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@@ -2042,1253 +2042,1238 @@ configurations; the following names are supported:
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TQM850L_config TQM855L_config TQM860L_config
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WALNUT405_config ZPC1900_config
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- Note: for some board special configuration names may exist; check if
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- additional information is available from the board vendor; for
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- instance, the TQM8xxL systems run normally at 50 MHz and use a
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- SCC for 10baseT ethernet; there are also systems with 80 MHz
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- CPU clock, and an optional Fast Ethernet module is available
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- for CPU's with FEC. You can select such additional "features"
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- when chosing the configuration, i. e.
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-
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- make TQM860L_config
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- - will configure for a plain TQM860L, i. e. 50MHz, no FEC
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-
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- make TQM860L_FEC_config
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- - will configure for a TQM860L at 50MHz with FEC for ethernet
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-
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- make TQM860L_80MHz_config
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- - will configure for a TQM860L at 80 MHz, with normal 10baseT
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- interface
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-
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- make TQM860L_FEC_80MHz_config
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- - will configure for a TQM860L at 80 MHz with FEC for ethernet
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-
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- make TQM823L_LCD_config
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- - will configure for a TQM823L with U-Boot console on LCD
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-
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- make TQM823L_LCD_80MHz_config
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- - will configure for a TQM823L at 80 MHz with U-Boot console on LCD
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-
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- etc.
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-
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-
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- Finally, type "make all", and you should get some working U-Boot
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- images ready for download to / installation on your system:
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-
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- - "u-boot.bin" is a raw binary image
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- - "u-boot" is an image in ELF binary format
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- - "u-boot.srec" is in Motorola S-Record format
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-
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-
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- Please be aware that the Makefiles assume you are using GNU make, so
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- for instance on NetBSD you might need to use "gmake" instead of
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- native "make".
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-
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-
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- If the system board that you have is not listed, then you will need
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- to port U-Boot to your hardware platform. To do this, follow these
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- steps:
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-
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- 1. Add a new configuration option for your board to the toplevel
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- "Makefile" and to the "MAKEALL" script, using the existing
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- entries as examples. Note that here and at many other places
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- boards and other names are listed in alphabetical sort order. Please
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- keep this order.
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- 2. Create a new directory to hold your board specific code. Add any
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- files you need. In your board directory, you will need at least
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- the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
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- 3. Create a new configuration file "include/configs/<board>.h" for
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- your board
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- 3. If you're porting U-Boot to a new CPU, then also create a new
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- directory to hold your CPU specific code. Add any files you need.
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- 4. Run "make <board>_config" with your new name.
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- 5. Type "make", and you should get a working "u-boot.srec" file
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- to be installed on your target system.
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- 6. Debug and solve any problems that might arise.
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- [Of course, this last step is much harder than it sounds.]
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-
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-
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- Testing of U-Boot Modifications, Ports to New Hardware, etc.:
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- ==============================================================
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-
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- If you have modified U-Boot sources (for instance added a new board
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- or support for new devices, a new CPU, etc.) you are expected to
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- provide feedback to the other developers. The feedback normally takes
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- the form of a "patch", i. e. a context diff against a certain (latest
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- official or latest in CVS) version of U-Boot sources.
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-
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- But before you submit such a patch, please verify that your modifi-
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- cation did not break existing code. At least make sure that *ALL* of
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- the supported boards compile WITHOUT ANY compiler warnings. To do so,
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- just run the "MAKEALL" script, which will configure and build U-Boot
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- for ALL supported system. Be warned, this will take a while. You can
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- select which (cross) compiler to use by passing a `CROSS_COMPILE'
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- environment variable to the script, i. e. to use the cross tools from
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- MontaVista's Hard Hat Linux you can type
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-
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- CROSS_COMPILE=ppc_8xx- MAKEALL
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-
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- or to build on a native PowerPC system you can type
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-
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- CROSS_COMPILE=' ' MAKEALL
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-
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- See also "U-Boot Porting Guide" below.
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-
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-
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- Monitor Commands - Overview:
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- ============================
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-
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- go - start application at address 'addr'
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- run - run commands in an environment variable
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- bootm - boot application image from memory
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- bootp - boot image via network using BootP/TFTP protocol
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- tftpboot- boot image via network using TFTP protocol
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- and env variables "ipaddr" and "serverip"
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- (and eventually "gatewayip")
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- rarpboot- boot image via network using RARP/TFTP protocol
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- diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
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- loads - load S-Record file over serial line
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- loadb - load binary file over serial line (kermit mode)
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- md - memory display
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- mm - memory modify (auto-incrementing)
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- nm - memory modify (constant address)
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- mw - memory write (fill)
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- cp - memory copy
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- cmp - memory compare
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- crc32 - checksum calculation
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- imd - i2c memory display
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- imm - i2c memory modify (auto-incrementing)
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- inm - i2c memory modify (constant address)
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- imw - i2c memory write (fill)
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- icrc32 - i2c checksum calculation
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- iprobe - probe to discover valid I2C chip addresses
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- iloop - infinite loop on address range
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- isdram - print SDRAM configuration information
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- sspi - SPI utility commands
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- base - print or set address offset
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- printenv- print environment variables
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- setenv - set environment variables
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- saveenv - save environment variables to persistent storage
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- protect - enable or disable FLASH write protection
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- erase - erase FLASH memory
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- flinfo - print FLASH memory information
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- bdinfo - print Board Info structure
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- iminfo - print header information for application image
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- coninfo - print console devices and informations
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- ide - IDE sub-system
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- loop - infinite loop on address range
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- mtest - simple RAM test
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- icache - enable or disable instruction cache
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- dcache - enable or disable data cache
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- reset - Perform RESET of the CPU
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- echo - echo args to console
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- version - print monitor version
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- help - print online help
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- ? - alias for 'help'
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-
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-
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- Monitor Commands - Detailed Description:
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- ========================================
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-
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- TODO.
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-
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- For now: just type "help <command>".
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-
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-
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- Environment Variables:
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- ======================
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-
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- U-Boot supports user configuration using Environment Variables which
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- can be made persistent by saving to Flash memory.
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-
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- Environment Variables are set using "setenv", printed using
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- "printenv", and saved to Flash using "saveenv". Using "setenv"
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- without a value can be used to delete a variable from the
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- environment. As long as you don't save the environment you are
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- working with an in-memory copy. In case the Flash area containing the
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- environment is erased by accident, a default environment is provided.
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-
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- Some configuration options can be set using Environment Variables:
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-
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- baudrate - see CONFIG_BAUDRATE
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-
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- bootdelay - see CONFIG_BOOTDELAY
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-
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- bootcmd - see CONFIG_BOOTCOMMAND
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-
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- bootargs - Boot arguments when booting an RTOS image
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-
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- bootfile - Name of the image to load with TFTP
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-
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- autoload - if set to "no" (any string beginning with 'n'),
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- "bootp" will just load perform a lookup of the
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- configuration from the BOOTP server, but not try to
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- load any image using TFTP
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-
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- autostart - if set to "yes", an image loaded using the "bootp",
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- "rarpboot", "tftpboot" or "diskboot" commands will
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- be automatically started (by internally calling
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- "bootm")
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-
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- If set to "no", a standalone image passed to the
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- "bootm" command will be copied to the load address
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- (and eventually uncompressed), but NOT be started.
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- This can be used to load and uncompress arbitrary
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- data.
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-
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- initrd_high - restrict positioning of initrd images:
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- If this variable is not set, initrd images will be
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- copied to the highest possible address in RAM; this
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- is usually what you want since it allows for
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- maximum initrd size. If for some reason you want to
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- make sure that the initrd image is loaded below the
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- CFG_BOOTMAPSZ limit, you can set this environment
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- variable to a value of "no" or "off" or "0".
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- Alternatively, you can set it to a maximum upper
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- address to use (U-Boot will still check that it
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- does not overwrite the U-Boot stack and data).
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-
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- For instance, when you have a system with 16 MB
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- RAM, and want to reserve 4 MB from use by Linux,
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- you can do this by adding "mem=12M" to the value of
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- the "bootargs" variable. However, now you must make
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- sure that the initrd image is placed in the first
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- 12 MB as well - this can be done with
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-
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- setenv initrd_high 00c00000
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-
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- If you set initrd_high to 0xFFFFFFFF, this is an
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- indication to U-Boot that all addresses are legal
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- for the Linux kernel, including addresses in flash
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- memory. In this case U-Boot will NOT COPY the
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- ramdisk at all. This may be useful to reduce the
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- boot time on your system, but requires that this
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- feature is supported by your Linux kernel.
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+Note: for some board special configuration names may exist; check if
|
|
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+ additional information is available from the board vendor; for
|
|
|
+ instance, the TQM823L systems are available without (standard)
|
|
|
+ or with LCD support. You can select such additional "features"
|
|
|
+ when chosing the configuration, i. e.
|
|
|
+
|
|
|
+ make TQM823L_config
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+ - will configure for a plain TQM823L, i. e. no LCD support
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+
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+ make TQM823L_LCD_config
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+ - will configure for a TQM823L with U-Boot console on LCD
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+
|
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+ etc.
|
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+
|
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+
|
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+Finally, type "make all", and you should get some working U-Boot
|
|
|
+images ready for download to / installation on your system:
|
|
|
+
|
|
|
+- "u-boot.bin" is a raw binary image
|
|
|
+- "u-boot" is an image in ELF binary format
|
|
|
+- "u-boot.srec" is in Motorola S-Record format
|
|
|
+
|
|
|
+
|
|
|
+Please be aware that the Makefiles assume you are using GNU make, so
|
|
|
+for instance on NetBSD you might need to use "gmake" instead of
|
|
|
+native "make".
|
|
|
+
|
|
|
+
|
|
|
+If the system board that you have is not listed, then you will need
|
|
|
+to port U-Boot to your hardware platform. To do this, follow these
|
|
|
+steps:
|
|
|
+
|
|
|
+1. Add a new configuration option for your board to the toplevel
|
|
|
+ "Makefile" and to the "MAKEALL" script, using the existing
|
|
|
+ entries as examples. Note that here and at many other places
|
|
|
+ boards and other names are listed in alphabetical sort order. Please
|
|
|
+ keep this order.
|
|
|
+2. Create a new directory to hold your board specific code. Add any
|
|
|
+ files you need. In your board directory, you will need at least
|
|
|
+ the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
|
|
|
+3. Create a new configuration file "include/configs/<board>.h" for
|
|
|
+ your board
|
|
|
+3. If you're porting U-Boot to a new CPU, then also create a new
|
|
|
+ directory to hold your CPU specific code. Add any files you need.
|
|
|
+4. Run "make <board>_config" with your new name.
|
|
|
+5. Type "make", and you should get a working "u-boot.srec" file
|
|
|
+ to be installed on your target system.
|
|
|
+6. Debug and solve any problems that might arise.
|
|
|
+ [Of course, this last step is much harder than it sounds.]
|
|
|
+
|
|
|
+
|
|
|
+Testing of U-Boot Modifications, Ports to New Hardware, etc.:
|
|
|
+==============================================================
|
|
|
+
|
|
|
+If you have modified U-Boot sources (for instance added a new board
|
|
|
+or support for new devices, a new CPU, etc.) you are expected to
|
|
|
+provide feedback to the other developers. The feedback normally takes
|
|
|
+the form of a "patch", i. e. a context diff against a certain (latest
|
|
|
+official or latest in CVS) version of U-Boot sources.
|
|
|
+
|
|
|
+But before you submit such a patch, please verify that your modifi-
|
|
|
+cation did not break existing code. At least make sure that *ALL* of
|
|
|
+the supported boards compile WITHOUT ANY compiler warnings. To do so,
|
|
|
+just run the "MAKEALL" script, which will configure and build U-Boot
|
|
|
+for ALL supported system. Be warned, this will take a while. You can
|
|
|
+select which (cross) compiler to use by passing a `CROSS_COMPILE'
|
|
|
+environment variable to the script, i. e. to use the cross tools from
|
|
|
+MontaVista's Hard Hat Linux you can type
|
|
|
+
|
|
|
+ CROSS_COMPILE=ppc_8xx- MAKEALL
|
|
|
+
|
|
|
+or to build on a native PowerPC system you can type
|
|
|
+
|
|
|
+ CROSS_COMPILE=' ' MAKEALL
|
|
|
+
|
|
|
+See also "U-Boot Porting Guide" below.
|
|
|
+
|
|
|
+
|
|
|
+Monitor Commands - Overview:
|
|
|
+============================
|
|
|
+
|
|
|
+go - start application at address 'addr'
|
|
|
+run - run commands in an environment variable
|
|
|
+bootm - boot application image from memory
|
|
|
+bootp - boot image via network using BootP/TFTP protocol
|
|
|
+tftpboot- boot image via network using TFTP protocol
|
|
|
+ and env variables "ipaddr" and "serverip"
|
|
|
+ (and eventually "gatewayip")
|
|
|
+rarpboot- boot image via network using RARP/TFTP protocol
|
|
|
+diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
|
|
|
+loads - load S-Record file over serial line
|
|
|
+loadb - load binary file over serial line (kermit mode)
|
|
|
+md - memory display
|
|
|
+mm - memory modify (auto-incrementing)
|
|
|
+nm - memory modify (constant address)
|
|
|
+mw - memory write (fill)
|
|
|
+cp - memory copy
|
|
|
+cmp - memory compare
|
|
|
+crc32 - checksum calculation
|
|
|
+imd - i2c memory display
|
|
|
+imm - i2c memory modify (auto-incrementing)
|
|
|
+inm - i2c memory modify (constant address)
|
|
|
+imw - i2c memory write (fill)
|
|
|
+icrc32 - i2c checksum calculation
|
|
|
+iprobe - probe to discover valid I2C chip addresses
|
|
|
+iloop - infinite loop on address range
|
|
|
+isdram - print SDRAM configuration information
|
|
|
+sspi - SPI utility commands
|
|
|
+base - print or set address offset
|
|
|
+printenv- print environment variables
|
|
|
+setenv - set environment variables
|
|
|
+saveenv - save environment variables to persistent storage
|
|
|
+protect - enable or disable FLASH write protection
|
|
|
+erase - erase FLASH memory
|
|
|
+flinfo - print FLASH memory information
|
|
|
+bdinfo - print Board Info structure
|
|
|
+iminfo - print header information for application image
|
|
|
+coninfo - print console devices and informations
|
|
|
+ide - IDE sub-system
|
|
|
+loop - infinite loop on address range
|
|
|
+mtest - simple RAM test
|
|
|
+icache - enable or disable instruction cache
|
|
|
+dcache - enable or disable data cache
|
|
|
+reset - Perform RESET of the CPU
|
|
|
+echo - echo args to console
|
|
|
+version - print monitor version
|
|
|
+help - print online help
|
|
|
+? - alias for 'help'
|
|
|
+
|
|
|
+
|
|
|
+Monitor Commands - Detailed Description:
|
|
|
+========================================
|
|
|
+
|
|
|
+TODO.
|
|
|
+
|
|
|
+For now: just type "help <command>".
|
|
|
+
|
|
|
+
|
|
|
+Environment Variables:
|
|
|
+======================
|
|
|
+
|
|
|
+U-Boot supports user configuration using Environment Variables which
|
|
|
+can be made persistent by saving to Flash memory.
|
|
|
|
|
|
- ipaddr - IP address; needed for tftpboot command
|
|
|
+Environment Variables are set using "setenv", printed using
|
|
|
+"printenv", and saved to Flash using "saveenv". Using "setenv"
|
|
|
+without a value can be used to delete a variable from the
|
|
|
+environment. As long as you don't save the environment you are
|
|
|
+working with an in-memory copy. In case the Flash area containing the
|
|
|
+environment is erased by accident, a default environment is provided.
|
|
|
|
|
|
- loadaddr - Default load address for commands like "bootp",
|
|
|
- "rarpboot", "tftpboot", "loadb" or "diskboot"
|
|
|
+Some configuration options can be set using Environment Variables:
|
|
|
|
|
|
- loads_echo - see CONFIG_LOADS_ECHO
|
|
|
+ baudrate - see CONFIG_BAUDRATE
|
|
|
|
|
|
- serverip - TFTP server IP address; needed for tftpboot command
|
|
|
+ bootdelay - see CONFIG_BOOTDELAY
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|
|
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|
- bootretry - see CONFIG_BOOT_RETRY_TIME
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+ bootcmd - see CONFIG_BOOTCOMMAND
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- bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
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|
|
+ bootargs - Boot arguments when booting an RTOS image
|
|
|
|
|
|
- bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
|
|
|
+ bootfile - Name of the image to load with TFTP
|
|
|
|
|
|
- ethprime - When CONFIG_NET_MULTI is enabled controls which
|
|
|
- interface is used first.
|
|
|
+ autoload - if set to "no" (any string beginning with 'n'),
|
|
|
+ "bootp" will just load perform a lookup of the
|
|
|
+ configuration from the BOOTP server, but not try to
|
|
|
+ load any image using TFTP
|
|
|
|
|
|
- ethact - When CONFIG_NET_MULTI is enabled controls which
|
|
|
- interface is currently active. For example you
|
|
|
- can do the following
|
|
|
+ autostart - if set to "yes", an image loaded using the "bootp",
|
|
|
+ "rarpboot", "tftpboot" or "diskboot" commands will
|
|
|
+ be automatically started (by internally calling
|
|
|
+ "bootm")
|
|
|
|
|
|
- => setenv ethact FEC ETHERNET
|
|
|
- => ping 192.168.0.1 # traffic sent on FEC ETHERNET
|
|
|
- => setenv ethact SCC ETHERNET
|
|
|
- => ping 10.0.0.1 # traffic sent on SCC ETHERNET
|
|
|
+ If set to "no", a standalone image passed to the
|
|
|
+ "bootm" command will be copied to the load address
|
|
|
+ (and eventually uncompressed), but NOT be started.
|
|
|
+ This can be used to load and uncompress arbitrary
|
|
|
+ data.
|
|
|
|
|
|
- netretry - When set to "no" each network operation will
|
|
|
- either succeed or fail without retrying.
|
|
|
- When set to "once" the network operation will
|
|
|
- fail when all the available network interfaces
|
|
|
- are tried once without success.
|
|
|
- Useful on scripts which control the retry operation
|
|
|
- themselves.
|
|
|
+ initrd_high - restrict positioning of initrd images:
|
|
|
+ If this variable is not set, initrd images will be
|
|
|
+ copied to the highest possible address in RAM; this
|
|
|
+ is usually what you want since it allows for
|
|
|
+ maximum initrd size. If for some reason you want to
|
|
|
+ make sure that the initrd image is loaded below the
|
|
|
+ CFG_BOOTMAPSZ limit, you can set this environment
|
|
|
+ variable to a value of "no" or "off" or "0".
|
|
|
+ Alternatively, you can set it to a maximum upper
|
|
|
+ address to use (U-Boot will still check that it
|
|
|
+ does not overwrite the U-Boot stack and data).
|
|
|
|
|
|
- vlan - When set to a value < 4095 the traffic over
|
|
|
- ethernet is encapsulated/received over 802.1q
|
|
|
- VLAN tagged frames.
|
|
|
+ For instance, when you have a system with 16 MB
|
|
|
+ RAM, and want to reserve 4 MB from use by Linux,
|
|
|
+ you can do this by adding "mem=12M" to the value of
|
|
|
+ the "bootargs" variable. However, now you must make
|
|
|
+ sure that the initrd image is placed in the first
|
|
|
+ 12 MB as well - this can be done with
|
|
|
|
|
|
- The following environment variables may be used and automatically
|
|
|
- updated by the network boot commands ("bootp" and "rarpboot"),
|
|
|
- depending the information provided by your boot server:
|
|
|
+ setenv initrd_high 00c00000
|
|
|
|
|
|
- bootfile - see above
|
|
|
- dnsip - IP address of your Domain Name Server
|
|
|
- dnsip2 - IP address of your secondary Domain Name Server
|
|
|
- gatewayip - IP address of the Gateway (Router) to use
|
|
|
- hostname - Target hostname
|
|
|
- ipaddr - see above
|
|
|
- netmask - Subnet Mask
|
|
|
- rootpath - Pathname of the root filesystem on the NFS server
|
|
|
- serverip - see above
|
|
|
+ If you set initrd_high to 0xFFFFFFFF, this is an
|
|
|
+ indication to U-Boot that all addresses are legal
|
|
|
+ for the Linux kernel, including addresses in flash
|
|
|
+ memory. In this case U-Boot will NOT COPY the
|
|
|
+ ramdisk at all. This may be useful to reduce the
|
|
|
+ boot time on your system, but requires that this
|
|
|
+ feature is supported by your Linux kernel.
|
|
|
|
|
|
+ ipaddr - IP address; needed for tftpboot command
|
|
|
|
|
|
- There are two special Environment Variables:
|
|
|
+ loadaddr - Default load address for commands like "bootp",
|
|
|
+ "rarpboot", "tftpboot", "loadb" or "diskboot"
|
|
|
|
|
|
- serial# - contains hardware identification information such
|
|
|
- as type string and/or serial number
|
|
|
- ethaddr - Ethernet address
|
|
|
+ loads_echo - see CONFIG_LOADS_ECHO
|
|
|
|
|
|
- These variables can be set only once (usually during manufacturing of
|
|
|
- the board). U-Boot refuses to delete or overwrite these variables
|
|
|
- once they have been set once.
|
|
|
+ serverip - TFTP server IP address; needed for tftpboot command
|
|
|
|
|
|
+ bootretry - see CONFIG_BOOT_RETRY_TIME
|
|
|
|
|
|
- Further special Environment Variables:
|
|
|
+ bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
|
|
|
|
|
|
- ver - Contains the U-Boot version string as printed
|
|
|
- with the "version" command. This variable is
|
|
|
- readonly (see CONFIG_VERSION_VARIABLE).
|
|
|
+ bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
|
|
|
|
|
|
+ ethprime - When CONFIG_NET_MULTI is enabled controls which
|
|
|
+ interface is used first.
|
|
|
|
|
|
- Please note that changes to some configuration parameters may take
|
|
|
- only effect after the next boot (yes, that's just like Windoze :-).
|
|
|
-
|
|
|
+ ethact - When CONFIG_NET_MULTI is enabled controls which
|
|
|
+ interface is currently active. For example you
|
|
|
+ can do the following
|
|
|
|
|
|
- Command Line Parsing:
|
|
|
- =====================
|
|
|
+ => setenv ethact FEC ETHERNET
|
|
|
+ => ping 192.168.0.1 # traffic sent on FEC ETHERNET
|
|
|
+ => setenv ethact SCC ETHERNET
|
|
|
+ => ping 10.0.0.1 # traffic sent on SCC ETHERNET
|
|
|
|
|
|
- There are two different command line parsers available with U-Boot:
|
|
|
- the old "simple" one, and the much more powerful "hush" shell:
|
|
|
+ netretry - When set to "no" each network operation will
|
|
|
+ either succeed or fail without retrying.
|
|
|
+ When set to "once" the network operation will
|
|
|
+ fail when all the available network interfaces
|
|
|
+ are tried once without success.
|
|
|
+ Useful on scripts which control the retry operation
|
|
|
+ themselves.
|
|
|
|
|
|
- Old, simple command line parser:
|
|
|
- --------------------------------
|
|
|
+ vlan - When set to a value < 4095 the traffic over
|
|
|
+ ethernet is encapsulated/received over 802.1q
|
|
|
+ VLAN tagged frames.
|
|
|
|
|
|
- - supports environment variables (through setenv / saveenv commands)
|
|
|
- - several commands on one line, separated by ';'
|
|
|
- - variable substitution using "... $(name) ..." syntax
|
|
|
- - special characters ('$', ';') can be escaped by prefixing with '\',
|
|
|
- for example:
|
|
|
- setenv bootcmd bootm \$(address)
|
|
|
- - You can also escape text by enclosing in single apostrophes, for example:
|
|
|
- setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
|
|
|
+The following environment variables may be used and automatically
|
|
|
+updated by the network boot commands ("bootp" and "rarpboot"),
|
|
|
+depending the information provided by your boot server:
|
|
|
|
|
|
- Hush shell:
|
|
|
- -----------
|
|
|
+ bootfile - see above
|
|
|
+ dnsip - IP address of your Domain Name Server
|
|
|
+ dnsip2 - IP address of your secondary Domain Name Server
|
|
|
+ gatewayip - IP address of the Gateway (Router) to use
|
|
|
+ hostname - Target hostname
|
|
|
+ ipaddr - see above
|
|
|
+ netmask - Subnet Mask
|
|
|
+ rootpath - Pathname of the root filesystem on the NFS server
|
|
|
+ serverip - see above
|
|
|
|
|
|
- - similar to Bourne shell, with control structures like
|
|
|
- if...then...else...fi, for...do...done; while...do...done,
|
|
|
- until...do...done, ...
|
|
|
- - supports environment ("global") variables (through setenv / saveenv
|
|
|
- commands) and local shell variables (through standard shell syntax
|
|
|
- "name=value"); only environment variables can be used with "run"
|
|
|
- command
|
|
|
|
|
|
- General rules:
|
|
|
- --------------
|
|
|
+There are two special Environment Variables:
|
|
|
|
|
|
- (1) If a command line (or an environment variable executed by a "run"
|
|
|
- command) contains several commands separated by semicolon, and
|
|
|
- one of these commands fails, then the remaining commands will be
|
|
|
- executed anyway.
|
|
|
+ serial# - contains hardware identification information such
|
|
|
+ as type string and/or serial number
|
|
|
+ ethaddr - Ethernet address
|
|
|
|
|
|
- (2) If you execute several variables with one call to run (i. e.
|
|
|
- calling run with a list af variables as arguments), any failing
|
|
|
- command will cause "run" to terminate, i. e. the remaining
|
|
|
- variables are not executed.
|
|
|
+These variables can be set only once (usually during manufacturing of
|
|
|
+the board). U-Boot refuses to delete or overwrite these variables
|
|
|
+once they have been set once.
|
|
|
|
|
|
- Note for Redundant Ethernet Interfaces:
|
|
|
- =======================================
|
|
|
|
|
|
- Some boards come with redundant ethernet interfaces; U-Boot supports
|
|
|
- such configurations and is capable of automatic selection of a
|
|
|
- "working" interface when needed. MAC assignment works as follows:
|
|
|
+Further special Environment Variables:
|
|
|
|
|
|
- Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
|
|
|
- MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
|
|
|
- "eth1addr" (=>eth1), "eth2addr", ...
|
|
|
+ ver - Contains the U-Boot version string as printed
|
|
|
+ with the "version" command. This variable is
|
|
|
+ readonly (see CONFIG_VERSION_VARIABLE).
|
|
|
|
|
|
- If the network interface stores some valid MAC address (for instance
|
|
|
- in SROM), this is used as default address if there is NO correspon-
|
|
|
- ding setting in the environment; if the corresponding environment
|
|
|
- variable is set, this overrides the settings in the card; that means:
|
|
|
|
|
|
- o If the SROM has a valid MAC address, and there is no address in the
|
|
|
- environment, the SROM's address is used.
|
|
|
+Please note that changes to some configuration parameters may take
|
|
|
+only effect after the next boot (yes, that's just like Windoze :-).
|
|
|
|
|
|
- o If there is no valid address in the SROM, and a definition in the
|
|
|
- environment exists, then the value from the environment variable is
|
|
|
- used.
|
|
|
|
|
|
- o If both the SROM and the environment contain a MAC address, and
|
|
|
- both addresses are the same, this MAC address is used.
|
|
|
+Command Line Parsing:
|
|
|
+=====================
|
|
|
|
|
|
- o If both the SROM and the environment contain a MAC address, and the
|
|
|
- addresses differ, the value from the environment is used and a
|
|
|
- warning is printed.
|
|
|
+There are two different command line parsers available with U-Boot:
|
|
|
+the old "simple" one, and the much more powerful "hush" shell:
|
|
|
|
|
|
- o If neither SROM nor the environment contain a MAC address, an error
|
|
|
- is raised.
|
|
|
+Old, simple command line parser:
|
|
|
+--------------------------------
|
|
|
|
|
|
+- supports environment variables (through setenv / saveenv commands)
|
|
|
+- several commands on one line, separated by ';'
|
|
|
+- variable substitution using "... $(name) ..." syntax
|
|
|
+- special characters ('$', ';') can be escaped by prefixing with '\',
|
|
|
+ for example:
|
|
|
+ setenv bootcmd bootm \$(address)
|
|
|
+- You can also escape text by enclosing in single apostrophes, for example:
|
|
|
+ setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
|
|
|
|
|
|
- Image Formats:
|
|
|
- ==============
|
|
|
+Hush shell:
|
|
|
+-----------
|
|
|
|
|
|
- The "boot" commands of this monitor operate on "image" files which
|
|
|
- can be basicly anything, preceeded by a special header; see the
|
|
|
- definitions in include/image.h for details; basicly, the header
|
|
|
- defines the following image properties:
|
|
|
+- similar to Bourne shell, with control structures like
|
|
|
+ if...then...else...fi, for...do...done; while...do...done,
|
|
|
+ until...do...done, ...
|
|
|
+- supports environment ("global") variables (through setenv / saveenv
|
|
|
+ commands) and local shell variables (through standard shell syntax
|
|
|
+ "name=value"); only environment variables can be used with "run"
|
|
|
+ command
|
|
|
+
|
|
|
+General rules:
|
|
|
+--------------
|
|
|
|
|
|
- * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
|
|
|
- 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
|
|
|
- LynxOS, pSOS, QNX, RTEMS, ARTOS;
|
|
|
- Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
|
|
|
- * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
|
|
|
- IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
|
|
|
- Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC).
|
|
|
- * Compression Type (uncompressed, gzip, bzip2)
|
|
|
- * Load Address
|
|
|
- * Entry Point
|
|
|
- * Image Name
|
|
|
- * Image Timestamp
|
|
|
+(1) If a command line (or an environment variable executed by a "run"
|
|
|
+ command) contains several commands separated by semicolon, and
|
|
|
+ one of these commands fails, then the remaining commands will be
|
|
|
+ executed anyway.
|
|
|
|
|
|
- The header is marked by a special Magic Number, and both the header
|
|
|
- and the data portions of the image are secured against corruption by
|
|
|
- CRC32 checksums.
|
|
|
+(2) If you execute several variables with one call to run (i. e.
|
|
|
+ calling run with a list af variables as arguments), any failing
|
|
|
+ command will cause "run" to terminate, i. e. the remaining
|
|
|
+ variables are not executed.
|
|
|
|
|
|
+Note for Redundant Ethernet Interfaces:
|
|
|
+=======================================
|
|
|
|
|
|
- Linux Support:
|
|
|
- ==============
|
|
|
+Some boards come with redundant ethernet interfaces; U-Boot supports
|
|
|
+such configurations and is capable of automatic selection of a
|
|
|
+"working" interface when needed. MAC assignment works as follows:
|
|
|
|
|
|
- Although U-Boot should support any OS or standalone application
|
|
|
- easily, the main focus has always been on Linux during the design of
|
|
|
- U-Boot.
|
|
|
+Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
|
|
|
+MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
|
|
|
+"eth1addr" (=>eth1), "eth2addr", ...
|
|
|
|
|
|
- U-Boot includes many features that so far have been part of some
|
|
|
- special "boot loader" code within the Linux kernel. Also, any
|
|
|
- "initrd" images to be used are no longer part of one big Linux image;
|
|
|
- instead, kernel and "initrd" are separate images. This implementation
|
|
|
- serves several purposes:
|
|
|
+If the network interface stores some valid MAC address (for instance
|
|
|
+in SROM), this is used as default address if there is NO correspon-
|
|
|
+ding setting in the environment; if the corresponding environment
|
|
|
+variable is set, this overrides the settings in the card; that means:
|
|
|
|
|
|
- - the same features can be used for other OS or standalone
|
|
|
- applications (for instance: using compressed images to reduce the
|
|
|
- Flash memory footprint)
|
|
|
+o If the SROM has a valid MAC address, and there is no address in the
|
|
|
+ environment, the SROM's address is used.
|
|
|
|
|
|
- - it becomes much easier to port new Linux kernel versions because
|
|
|
- lots of low-level, hardware dependent stuff are done by U-Boot
|
|
|
+o If there is no valid address in the SROM, and a definition in the
|
|
|
+ environment exists, then the value from the environment variable is
|
|
|
+ used.
|
|
|
|
|
|
- - the same Linux kernel image can now be used with different "initrd"
|
|
|
- images; of course this also means that different kernel images can
|
|
|
- be run with the same "initrd". This makes testing easier (you don't
|
|
|
- have to build a new "zImage.initrd" Linux image when you just
|
|
|
- change a file in your "initrd"). Also, a field-upgrade of the
|
|
|
- software is easier now.
|
|
|
+o If both the SROM and the environment contain a MAC address, and
|
|
|
+ both addresses are the same, this MAC address is used.
|
|
|
|
|
|
+o If both the SROM and the environment contain a MAC address, and the
|
|
|
+ addresses differ, the value from the environment is used and a
|
|
|
+ warning is printed.
|
|
|
|
|
|
- Linux HOWTO:
|
|
|
- ============
|
|
|
+o If neither SROM nor the environment contain a MAC address, an error
|
|
|
+ is raised.
|
|
|
|
|
|
- Porting Linux to U-Boot based systems:
|
|
|
- ---------------------------------------
|
|
|
|
|
|
- U-Boot cannot save you from doing all the necessary modifications to
|
|
|
- configure the Linux device drivers for use with your target hardware
|
|
|
- (no, we don't intend to provide a full virtual machine interface to
|
|
|
- Linux :-).
|
|
|
+Image Formats:
|
|
|
+==============
|
|
|
|
|
|
- But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
|
|
|
+The "boot" commands of this monitor operate on "image" files which
|
|
|
+can be basicly anything, preceeded by a special header; see the
|
|
|
+definitions in include/image.h for details; basicly, the header
|
|
|
+defines the following image properties:
|
|
|
|
|
|
- Just make sure your machine specific header file (for instance
|
|
|
- include/asm-ppc/tqm8xx.h) includes the same definition of the Board
|
|
|
- Information structure as we define in include/u-boot.h, and make
|
|
|
- sure that your definition of IMAP_ADDR uses the same value as your
|
|
|
- U-Boot configuration in CFG_IMMR.
|
|
|
+* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
|
|
|
+ 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
|
|
|
+ LynxOS, pSOS, QNX, RTEMS, ARTOS;
|
|
|
+ Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
|
|
|
+* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
|
|
|
+ IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
|
|
|
+ Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC).
|
|
|
+* Compression Type (uncompressed, gzip, bzip2)
|
|
|
+* Load Address
|
|
|
+* Entry Point
|
|
|
+* Image Name
|
|
|
+* Image Timestamp
|
|
|
|
|
|
+The header is marked by a special Magic Number, and both the header
|
|
|
+and the data portions of the image are secured against corruption by
|
|
|
+CRC32 checksums.
|
|
|
|
|
|
- Configuring the Linux kernel:
|
|
|
- -----------------------------
|
|
|
|
|
|
- No specific requirements for U-Boot. Make sure you have some root
|
|
|
- device (initial ramdisk, NFS) for your target system.
|
|
|
+Linux Support:
|
|
|
+==============
|
|
|
|
|
|
+Although U-Boot should support any OS or standalone application
|
|
|
+easily, the main focus has always been on Linux during the design of
|
|
|
+U-Boot.
|
|
|
|
|
|
- Building a Linux Image:
|
|
|
- -----------------------
|
|
|
+U-Boot includes many features that so far have been part of some
|
|
|
+special "boot loader" code within the Linux kernel. Also, any
|
|
|
+"initrd" images to be used are no longer part of one big Linux image;
|
|
|
+instead, kernel and "initrd" are separate images. This implementation
|
|
|
+serves several purposes:
|
|
|
|
|
|
- With U-Boot, "normal" build targets like "zImage" or "bzImage" are
|
|
|
- not used. If you use recent kernel source, a new build target
|
|
|
- "uImage" will exist which automatically builds an image usable by
|
|
|
- U-Boot. Most older kernels also have support for a "pImage" target,
|
|
|
- which was introduced for our predecessor project PPCBoot and uses a
|
|
|
- 100% compatible format.
|
|
|
+- the same features can be used for other OS or standalone
|
|
|
+ applications (for instance: using compressed images to reduce the
|
|
|
+ Flash memory footprint)
|
|
|
|
|
|
- Example:
|
|
|
+- it becomes much easier to port new Linux kernel versions because
|
|
|
+ lots of low-level, hardware dependent stuff are done by U-Boot
|
|
|
|
|
|
- make TQM850L_config
|
|
|
- make oldconfig
|
|
|
- make dep
|
|
|
- make uImage
|
|
|
+- the same Linux kernel image can now be used with different "initrd"
|
|
|
+ images; of course this also means that different kernel images can
|
|
|
+ be run with the same "initrd". This makes testing easier (you don't
|
|
|
+ have to build a new "zImage.initrd" Linux image when you just
|
|
|
+ change a file in your "initrd"). Also, a field-upgrade of the
|
|
|
+ software is easier now.
|
|
|
|
|
|
- The "uImage" build target uses a special tool (in 'tools/mkimage') to
|
|
|
- encapsulate a compressed Linux kernel image with header information,
|
|
|
- CRC32 checksum etc. for use with U-Boot. This is what we are doing:
|
|
|
|
|
|
- * build a standard "vmlinux" kernel image (in ELF binary format):
|
|
|
-
|
|
|
- * convert the kernel into a raw binary image:
|
|
|
-
|
|
|
- ${CROSS_COMPILE}-objcopy -O binary \
|
|
|
- -R .note -R .comment \
|
|
|
- -S vmlinux linux.bin
|
|
|
-
|
|
|
- * compress the binary image:
|
|
|
-
|
|
|
- gzip -9 linux.bin
|
|
|
+Linux HOWTO:
|
|
|
+============
|
|
|
|
|
|
- * package compressed binary image for U-Boot:
|
|
|
+Porting Linux to U-Boot based systems:
|
|
|
+---------------------------------------
|
|
|
|
|
|
- mkimage -A ppc -O linux -T kernel -C gzip \
|
|
|
- -a 0 -e 0 -n "Linux Kernel Image" \
|
|
|
- -d linux.bin.gz uImage
|
|
|
+U-Boot cannot save you from doing all the necessary modifications to
|
|
|
+configure the Linux device drivers for use with your target hardware
|
|
|
+(no, we don't intend to provide a full virtual machine interface to
|
|
|
+Linux :-).
|
|
|
|
|
|
+But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
|
|
|
|
|
|
- The "mkimage" tool can also be used to create ramdisk images for use
|
|
|
- with U-Boot, either separated from the Linux kernel image, or
|
|
|
- combined into one file. "mkimage" encapsulates the images with a 64
|
|
|
- byte header containing information about target architecture,
|
|
|
- operating system, image type, compression method, entry points, time
|
|
|
- stamp, CRC32 checksums, etc.
|
|
|
+Just make sure your machine specific header file (for instance
|
|
|
+include/asm-ppc/tqm8xx.h) includes the same definition of the Board
|
|
|
+Information structure as we define in include/u-boot.h, and make
|
|
|
+sure that your definition of IMAP_ADDR uses the same value as your
|
|
|
+U-Boot configuration in CFG_IMMR.
|
|
|
|
|
|
- "mkimage" can be called in two ways: to verify existing images and
|
|
|
- print the header information, or to build new images.
|
|
|
|
|
|
- In the first form (with "-l" option) mkimage lists the information
|
|
|
- contained in the header of an existing U-Boot image; this includes
|
|
|
- checksum verification:
|
|
|
+Configuring the Linux kernel:
|
|
|
+-----------------------------
|
|
|
|
|
|
- tools/mkimage -l image
|
|
|
- -l ==> list image header information
|
|
|
+No specific requirements for U-Boot. Make sure you have some root
|
|
|
+device (initial ramdisk, NFS) for your target system.
|
|
|
+
|
|
|
+
|
|
|
+Building a Linux Image:
|
|
|
+-----------------------
|
|
|
|
|
|
- The second form (with "-d" option) is used to build a U-Boot image
|
|
|
- from a "data file" which is used as image payload:
|
|
|
+With U-Boot, "normal" build targets like "zImage" or "bzImage" are
|
|
|
+not used. If you use recent kernel source, a new build target
|
|
|
+"uImage" will exist which automatically builds an image usable by
|
|
|
+U-Boot. Most older kernels also have support for a "pImage" target,
|
|
|
+which was introduced for our predecessor project PPCBoot and uses a
|
|
|
+100% compatible format.
|
|
|
+
|
|
|
+Example:
|
|
|
+
|
|
|
+ make TQM850L_config
|
|
|
+ make oldconfig
|
|
|
+ make dep
|
|
|
+ make uImage
|
|
|
+
|
|
|
+The "uImage" build target uses a special tool (in 'tools/mkimage') to
|
|
|
+encapsulate a compressed Linux kernel image with header information,
|
|
|
+CRC32 checksum etc. for use with U-Boot. This is what we are doing:
|
|
|
+
|
|
|
+* build a standard "vmlinux" kernel image (in ELF binary format):
|
|
|
+
|
|
|
+* convert the kernel into a raw binary image:
|
|
|
+
|
|
|
+ ${CROSS_COMPILE}-objcopy -O binary \
|
|
|
+ -R .note -R .comment \
|
|
|
+ -S vmlinux linux.bin
|
|
|
+
|
|
|
+* compress the binary image:
|
|
|
+
|
|
|
+ gzip -9 linux.bin
|
|
|
+
|
|
|
+* package compressed binary image for U-Boot:
|
|
|
+
|
|
|
+ mkimage -A ppc -O linux -T kernel -C gzip \
|
|
|
+ -a 0 -e 0 -n "Linux Kernel Image" \
|
|
|
+ -d linux.bin.gz uImage
|
|
|
|
|
|
- tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
|
|
|
- -n name -d data_file image
|
|
|
- -A ==> set architecture to 'arch'
|
|
|
- -O ==> set operating system to 'os'
|
|
|
- -T ==> set image type to 'type'
|
|
|
- -C ==> set compression type 'comp'
|
|
|
- -a ==> set load address to 'addr' (hex)
|
|
|
- -e ==> set entry point to 'ep' (hex)
|
|
|
- -n ==> set image name to 'name'
|
|
|
- -d ==> use image data from 'datafile'
|
|
|
|
|
|
- Right now, all Linux kernels use the same load address (0x00000000),
|
|
|
- but the entry point address depends on the kernel version:
|
|
|
+The "mkimage" tool can also be used to create ramdisk images for use
|
|
|
+with U-Boot, either separated from the Linux kernel image, or
|
|
|
+combined into one file. "mkimage" encapsulates the images with a 64
|
|
|
+byte header containing information about target architecture,
|
|
|
+operating system, image type, compression method, entry points, time
|
|
|
+stamp, CRC32 checksums, etc.
|
|
|
+
|
|
|
+"mkimage" can be called in two ways: to verify existing images and
|
|
|
+print the header information, or to build new images.
|
|
|
+
|
|
|
+In the first form (with "-l" option) mkimage lists the information
|
|
|
+contained in the header of an existing U-Boot image; this includes
|
|
|
+checksum verification:
|
|
|
|
|
|
- - 2.2.x kernels have the entry point at 0x0000000C,
|
|
|
- - 2.3.x and later kernels have the entry point at 0x00000000.
|
|
|
+ tools/mkimage -l image
|
|
|
+ -l ==> list image header information
|
|
|
+
|
|
|
+The second form (with "-d" option) is used to build a U-Boot image
|
|
|
+from a "data file" which is used as image payload:
|
|
|
+
|
|
|
+ tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
|
|
|
+ -n name -d data_file image
|
|
|
+ -A ==> set architecture to 'arch'
|
|
|
+ -O ==> set operating system to 'os'
|
|
|
+ -T ==> set image type to 'type'
|
|
|
+ -C ==> set compression type 'comp'
|
|
|
+ -a ==> set load address to 'addr' (hex)
|
|
|
+ -e ==> set entry point to 'ep' (hex)
|
|
|
+ -n ==> set image name to 'name'
|
|
|
+ -d ==> use image data from 'datafile'
|
|
|
+
|
|
|
+Right now, all Linux kernels use the same load address (0x00000000),
|
|
|
+but the entry point address depends on the kernel version:
|
|
|
+
|
|
|
+- 2.2.x kernels have the entry point at 0x0000000C,
|
|
|
+- 2.3.x and later kernels have the entry point at 0x00000000.
|
|
|
+
|
|
|
+So a typical call to build a U-Boot image would read:
|
|
|
+
|
|
|
+ -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
|
|
|
+ > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
|
|
|
+ > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
|
|
|
+ > examples/uImage.TQM850L
|
|
|
+ Image Name: 2.4.4 kernel for TQM850L
|
|
|
+ Created: Wed Jul 19 02:34:59 2000
|
|
|
+ Image Type: PowerPC Linux Kernel Image (gzip compressed)
|
|
|
+ Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
|
|
|
+ Load Address: 0x00000000
|
|
|
+ Entry Point: 0x00000000
|
|
|
+
|
|
|
+To verify the contents of the image (or check for corruption):
|
|
|
+
|
|
|
+ -> tools/mkimage -l examples/uImage.TQM850L
|
|
|
+ Image Name: 2.4.4 kernel for TQM850L
|
|
|
+ Created: Wed Jul 19 02:34:59 2000
|
|
|
+ Image Type: PowerPC Linux Kernel Image (gzip compressed)
|
|
|
+ Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
|
|
|
+ Load Address: 0x00000000
|
|
|
+ Entry Point: 0x00000000
|
|
|
+
|
|
|
+NOTE: for embedded systems where boot time is critical you can trade
|
|
|
+speed for memory and install an UNCOMPRESSED image instead: this
|
|
|
+needs more space in Flash, but boots much faster since it does not
|
|
|
+need to be uncompressed:
|
|
|
+
|
|
|
+ -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
|
|
|
+ -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
|
|
|
+ > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
|
|
|
+ > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
|
|
|
+ > examples/uImage.TQM850L-uncompressed
|
|
|
+ Image Name: 2.4.4 kernel for TQM850L
|
|
|
+ Created: Wed Jul 19 02:34:59 2000
|
|
|
+ Image Type: PowerPC Linux Kernel Image (uncompressed)
|
|
|
+ Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
|
|
|
+ Load Address: 0x00000000
|
|
|
+ Entry Point: 0x00000000
|
|
|
+
|
|
|
+
|
|
|
+Similar you can build U-Boot images from a 'ramdisk.image.gz' file
|
|
|
+when your kernel is intended to use an initial ramdisk:
|
|
|
+
|
|
|
+ -> tools/mkimage -n 'Simple Ramdisk Image' \
|
|
|
+ > -A ppc -O linux -T ramdisk -C gzip \
|
|
|
+ > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
|
|
|
+ Image Name: Simple Ramdisk Image
|
|
|
+ Created: Wed Jan 12 14:01:50 2000
|
|
|
+ Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
|
|
|
+ Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
|
|
|
+ Load Address: 0x00000000
|
|
|
+ Entry Point: 0x00000000
|
|
|
+
|
|
|
+
|
|
|
+Installing a Linux Image:
|
|
|
+-------------------------
|
|
|
+
|
|
|
+To downloading a U-Boot image over the serial (console) interface,
|
|
|
+you must convert the image to S-Record format:
|
|
|
+
|
|
|
+ objcopy -I binary -O srec examples/image examples/image.srec
|
|
|
+
|
|
|
+The 'objcopy' does not understand the information in the U-Boot
|
|
|
+image header, so the resulting S-Record file will be relative to
|
|
|
+address 0x00000000. To load it to a given address, you need to
|
|
|
+specify the target address as 'offset' parameter with the 'loads'
|
|
|
+command.
|
|
|
+
|
|
|
+Example: install the image to address 0x40100000 (which on the
|
|
|
+TQM8xxL is in the first Flash bank):
|
|
|
+
|
|
|
+ => erase 40100000 401FFFFF
|
|
|
+
|
|
|
+ .......... done
|
|
|
+ Erased 8 sectors
|
|
|
+
|
|
|
+ => loads 40100000
|
|
|
+ ## Ready for S-Record download ...
|
|
|
+ ~>examples/image.srec
|
|
|
+ 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
|
|
|
+ ...
|
|
|
+ 15989 15990 15991 15992
|
|
|
+ [file transfer complete]
|
|
|
+ [connected]
|
|
|
+ ## Start Addr = 0x00000000
|
|
|
+
|
|
|
+
|
|
|
+You can check the success of the download using the 'iminfo' command;
|
|
|
+this includes a checksum verification so you can be sure no data
|
|
|
+corruption happened:
|
|
|
+
|
|
|
+ => imi 40100000
|
|
|
+
|
|
|
+ ## Checking Image at 40100000 ...
|
|
|
+ Image Name: 2.2.13 for initrd on TQM850L
|
|
|
+ Image Type: PowerPC Linux Kernel Image (gzip compressed)
|
|
|
+ Data Size: 335725 Bytes = 327 kB = 0 MB
|
|
|
+ Load Address: 00000000
|
|
|
+ Entry Point: 0000000c
|
|
|
+ Verifying Checksum ... OK
|
|
|
+
|
|
|
+
|
|
|
+Boot Linux:
|
|
|
+-----------
|
|
|
+
|
|
|
+The "bootm" command is used to boot an application that is stored in
|
|
|
+memory (RAM or Flash). In case of a Linux kernel image, the contents
|
|
|
+of the "bootargs" environment variable is passed to the kernel as
|
|
|
+parameters. You can check and modify this variable using the
|
|
|
+"printenv" and "setenv" commands:
|
|
|
+
|
|
|
+
|
|
|
+ => printenv bootargs
|
|
|
+ bootargs=root=/dev/ram
|
|
|
+
|
|
|
+ => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
|
|
|
+
|
|
|
+ => printenv bootargs
|
|
|
+ bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
|
|
|
+
|
|
|
+ => bootm 40020000
|
|
|
+ ## Booting Linux kernel at 40020000 ...
|
|
|
+ Image Name: 2.2.13 for NFS on TQM850L
|
|
|
+ Image Type: PowerPC Linux Kernel Image (gzip compressed)
|
|
|
+ Data Size: 381681 Bytes = 372 kB = 0 MB
|
|
|
+ Load Address: 00000000
|
|
|
+ Entry Point: 0000000c
|
|
|
+ Verifying Checksum ... OK
|
|
|
+ Uncompressing Kernel Image ... OK
|
|
|
+ Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
|
|
|
+ Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
|
|
|
+ time_init: decrementer frequency = 187500000/60
|
|
|
+ Calibrating delay loop... 49.77 BogoMIPS
|
|
|
+ Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
|
|
|
+ ...
|
|
|
+
|
|
|
+If you want to boot a Linux kernel with initial ram disk, you pass
|
|
|
+the memory addresses of both the kernel and the initrd image (PPBCOOT
|
|
|
+format!) to the "bootm" command:
|
|
|
+
|
|
|
+ => imi 40100000 40200000
|
|
|
+
|
|
|
+ ## Checking Image at 40100000 ...
|
|
|
+ Image Name: 2.2.13 for initrd on TQM850L
|
|
|
+ Image Type: PowerPC Linux Kernel Image (gzip compressed)
|
|
|
+ Data Size: 335725 Bytes = 327 kB = 0 MB
|
|
|
+ Load Address: 00000000
|
|
|
+ Entry Point: 0000000c
|
|
|
+ Verifying Checksum ... OK
|
|
|
+
|
|
|
+ ## Checking Image at 40200000 ...
|
|
|
+ Image Name: Simple Ramdisk Image
|
|
|
+ Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
|
|
|
+ Data Size: 566530 Bytes = 553 kB = 0 MB
|
|
|
+ Load Address: 00000000
|
|
|
+ Entry Point: 00000000
|
|
|
+ Verifying Checksum ... OK
|
|
|
+
|
|
|
+ => bootm 40100000 40200000
|
|
|
+ ## Booting Linux kernel at 40100000 ...
|
|
|
+ Image Name: 2.2.13 for initrd on TQM850L
|
|
|
+ Image Type: PowerPC Linux Kernel Image (gzip compressed)
|
|
|
+ Data Size: 335725 Bytes = 327 kB = 0 MB
|
|
|
+ Load Address: 00000000
|
|
|
+ Entry Point: 0000000c
|
|
|
+ Verifying Checksum ... OK
|
|
|
+ Uncompressing Kernel Image ... OK
|
|
|
+ ## Loading RAMDisk Image at 40200000 ...
|
|
|
+ Image Name: Simple Ramdisk Image
|
|
|
+ Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
|
|
|
+ Data Size: 566530 Bytes = 553 kB = 0 MB
|
|
|
+ Load Address: 00000000
|
|
|
+ Entry Point: 00000000
|
|
|
+ Verifying Checksum ... OK
|
|
|
+ Loading Ramdisk ... OK
|
|
|
+ Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
|
|
|
+ Boot arguments: root=/dev/ram
|
|
|
+ time_init: decrementer frequency = 187500000/60
|
|
|
+ Calibrating delay loop... 49.77 BogoMIPS
|
|
|
+ ...
|
|
|
+ RAMDISK: Compressed image found at block 0
|
|
|
+ VFS: Mounted root (ext2 filesystem).
|
|
|
+
|
|
|
+ bash#
|
|
|
+
|
|
|
+More About U-Boot Image Types:
|
|
|
+------------------------------
|
|
|
+
|
|
|
+U-Boot supports the following image types:
|
|
|
+
|
|
|
+ "Standalone Programs" are directly runnable in the environment
|
|
|
+ provided by U-Boot; it is expected that (if they behave
|
|
|
+ well) you can continue to work in U-Boot after return from
|
|
|
+ the Standalone Program.
|
|
|
+ "OS Kernel Images" are usually images of some Embedded OS which
|
|
|
+ will take over control completely. Usually these programs
|
|
|
+ will install their own set of exception handlers, device
|
|
|
+ drivers, set up the MMU, etc. - this means, that you cannot
|
|
|
+ expect to re-enter U-Boot except by resetting the CPU.
|
|
|
+ "RAMDisk Images" are more or less just data blocks, and their
|
|
|
+ parameters (address, size) are passed to an OS kernel that is
|
|
|
+ being started.
|
|
|
+ "Multi-File Images" contain several images, typically an OS
|
|
|
+ (Linux) kernel image and one or more data images like
|
|
|
+ RAMDisks. This construct is useful for instance when you want
|
|
|
+ to boot over the network using BOOTP etc., where the boot
|
|
|
+ server provides just a single image file, but you want to get
|
|
|
+ for instance an OS kernel and a RAMDisk image.
|
|
|
+
|
|
|
+ "Multi-File Images" start with a list of image sizes, each
|
|
|
+ image size (in bytes) specified by an "uint32_t" in network
|
|
|
+ byte order. This list is terminated by an "(uint32_t)0".
|
|
|
+ Immediately after the terminating 0 follow the images, one by
|
|
|
+ one, all aligned on "uint32_t" boundaries (size rounded up to
|
|
|
+ a multiple of 4 bytes).
|
|
|
+
|
|
|
+ "Firmware Images" are binary images containing firmware (like
|
|
|
+ U-Boot or FPGA images) which usually will be programmed to
|
|
|
+ flash memory.
|
|
|
+
|
|
|
+ "Script files" are command sequences that will be executed by
|
|
|
+ U-Boot's command interpreter; this feature is especially
|
|
|
+ useful when you configure U-Boot to use a real shell (hush)
|
|
|
+ as command interpreter.
|
|
|
+
|
|
|
+
|
|
|
+Standalone HOWTO:
|
|
|
+=================
|
|
|
+
|
|
|
+One of the features of U-Boot is that you can dynamically load and
|
|
|
+run "standalone" applications, which can use some resources of
|
|
|
+U-Boot like console I/O functions or interrupt services.
|
|
|
+
|
|
|
+Two simple examples are included with the sources:
|
|
|
+
|
|
|
+"Hello World" Demo:
|
|
|
+-------------------
|
|
|
+
|
|
|
+'examples/hello_world.c' contains a small "Hello World" Demo
|
|
|
+application; it is automatically compiled when you build U-Boot.
|
|
|
+It's configured to run at address 0x00040004, so you can play with it
|
|
|
+like that:
|
|
|
+
|
|
|
+ => loads
|
|
|
+ ## Ready for S-Record download ...
|
|
|
+ ~>examples/hello_world.srec
|
|
|
+ 1 2 3 4 5 6 7 8 9 10 11 ...
|
|
|
+ [file transfer complete]
|
|
|
+ [connected]
|
|
|
+ ## Start Addr = 0x00040004
|
|
|
+
|
|
|
+ => go 40004 Hello World! This is a test.
|
|
|
+ ## Starting application at 0x00040004 ...
|
|
|
+ Hello World
|
|
|
+ argc = 7
|
|
|
+ argv[0] = "40004"
|
|
|
+ argv[1] = "Hello"
|
|
|
+ argv[2] = "World!"
|
|
|
+ argv[3] = "This"
|
|
|
+ argv[4] = "is"
|
|
|
+ argv[5] = "a"
|
|
|
+ argv[6] = "test."
|
|
|
+ argv[7] = "<NULL>"
|
|
|
+ Hit any key to exit ...
|
|
|
+
|
|
|
+ ## Application terminated, rc = 0x0
|
|
|
+
|
|
|
+Another example, which demonstrates how to register a CPM interrupt
|
|
|
+handler with the U-Boot code, can be found in 'examples/timer.c'.
|
|
|
+Here, a CPM timer is set up to generate an interrupt every second.
|
|
|
+The interrupt service routine is trivial, just printing a '.'
|
|
|
+character, but this is just a demo program. The application can be
|
|
|
+controlled by the following keys:
|
|
|
+
|
|
|
+ ? - print current values og the CPM Timer registers
|
|
|
+ b - enable interrupts and start timer
|
|
|
+ e - stop timer and disable interrupts
|
|
|
+ q - quit application
|
|
|
+
|
|
|
+ => loads
|
|
|
+ ## Ready for S-Record download ...
|
|
|
+ ~>examples/timer.srec
|
|
|
+ 1 2 3 4 5 6 7 8 9 10 11 ...
|
|
|
+ [file transfer complete]
|
|
|
+ [connected]
|
|
|
+ ## Start Addr = 0x00040004
|
|
|
+
|
|
|
+ => go 40004
|
|
|
+ ## Starting application at 0x00040004 ...
|
|
|
+ TIMERS=0xfff00980
|
|
|
+ Using timer 1
|
|
|
+ tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
|
|
|
+
|
|
|
+Hit 'b':
|
|
|
+ [q, b, e, ?] Set interval 1000000 us
|
|
|
+ Enabling timer
|
|
|
+Hit '?':
|
|
|
+ [q, b, e, ?] ........
|
|
|
+ tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
|
|
|
+Hit '?':
|
|
|
+ [q, b, e, ?] .
|
|
|
+ tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
|
|
|
+Hit '?':
|
|
|
+ [q, b, e, ?] .
|
|
|
+ tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
|
|
|
+Hit '?':
|
|
|
+ [q, b, e, ?] .
|
|
|
+ tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
|
|
|
+Hit 'e':
|
|
|
+ [q, b, e, ?] ...Stopping timer
|
|
|
+Hit 'q':
|
|
|
+ [q, b, e, ?] ## Application terminated, rc = 0x0
|
|
|
+
|
|
|
+
|
|
|
+Minicom warning:
|
|
|
+================
|
|
|
+
|
|
|
+Over time, many people have reported problems when trying to use the
|
|
|
+"minicom" terminal emulation program for serial download. I (wd)
|
|
|
+consider minicom to be broken, and recommend not to use it. Under
|
|
|
+Unix, I recommend to use C-Kermit for general purpose use (and
|
|
|
+especially for kermit binary protocol download ("loadb" command), and
|
|
|
+use "cu" for S-Record download ("loads" command).
|
|
|
+
|
|
|
+Nevertheless, if you absolutely want to use it try adding this
|
|
|
+configuration to your "File transfer protocols" section:
|
|
|
+
|
|
|
+ Name Program Name U/D FullScr IO-Red. Multi
|
|
|
+ X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
|
|
|
+ Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
|
|
|
+
|
|
|
+
|
|
|
+NetBSD Notes:
|
|
|
+=============
|
|
|
+
|
|
|
+Starting at version 0.9.2, U-Boot supports NetBSD both as host
|
|
|
+(build U-Boot) and target system (boots NetBSD/mpc8xx).
|
|
|
+
|
|
|
+Building requires a cross environment; it is known to work on
|
|
|
+NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
|
|
|
+need gmake since the Makefiles are not compatible with BSD make).
|
|
|
+Note that the cross-powerpc package does not install include files;
|
|
|
+attempting to build U-Boot will fail because <machine/ansi.h> is
|
|
|
+missing. This file has to be installed and patched manually:
|
|
|
+
|
|
|
+ # cd /usr/pkg/cross/powerpc-netbsd/include
|
|
|
+ # mkdir powerpc
|
|
|
+ # ln -s powerpc machine
|
|
|
+ # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
|
|
|
+ # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
|
|
|
+
|
|
|
+Native builds *don't* work due to incompatibilities between native
|
|
|
+and U-Boot include files.
|
|
|
+
|
|
|
+Booting assumes that (the first part of) the image booted is a
|
|
|
+stage-2 loader which in turn loads and then invokes the kernel
|
|
|
+proper. Loader sources will eventually appear in the NetBSD source
|
|
|
+tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
|
|
|
+meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for
|
|
|
+details.
|
|
|
+
|
|
|
+
|
|
|
+Implementation Internals:
|
|
|
+=========================
|
|
|
+
|
|
|
+The following is not intended to be a complete description of every
|
|
|
+implementation detail. However, it should help to understand the
|
|
|
+inner workings of U-Boot and make it easier to port it to custom
|
|
|
+hardware.
|
|
|
+
|
|
|
+
|
|
|
+Initial Stack, Global Data:
|
|
|
+---------------------------
|
|
|
+
|
|
|
+The implementation of U-Boot is complicated by the fact that U-Boot
|
|
|
+starts running out of ROM (flash memory), usually without access to
|
|
|
+system RAM (because the memory controller is not initialized yet).
|
|
|
+This means that we don't have writable Data or BSS segments, and BSS
|
|
|
+is not initialized as zero. To be able to get a C environment working
|
|
|
+at all, we have to allocate at least a minimal stack. Implementation
|
|
|
+options for this are defined and restricted by the CPU used: Some CPU
|
|
|
+models provide on-chip memory (like the IMMR area on MPC8xx and
|
|
|
+MPC826x processors), on others (parts of) the data cache can be
|
|
|
+locked as (mis-) used as memory, etc.
|
|
|
+
|
|
|
+ Chris Hallinan posted a good summary of these issues to the
|
|
|
+ u-boot-users mailing list:
|
|
|
+
|
|
|
+ Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
|
|
|
+ From: "Chris Hallinan" <clh@net1plus.com>
|
|
|
+ Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
|
|
|
+ ...
|
|
|
+
|
|
|
+ Correct me if I'm wrong, folks, but the way I understand it
|
|
|
+ is this: Using DCACHE as initial RAM for Stack, etc, does not
|
|
|
+ require any physical RAM backing up the cache. The cleverness
|
|
|
+ is that the cache is being used as a temporary supply of
|
|
|
+ necessary storage before the SDRAM controller is setup. It's
|
|
|
+ beyond the scope of this list to expain the details, but you
|
|
|
+ can see how this works by studying the cache architecture and
|
|
|
+ operation in the architecture and processor-specific manuals.
|
|
|
+
|
|
|
+ OCM is On Chip Memory, which I believe the 405GP has 4K. It
|
|
|
+ is another option for the system designer to use as an
|
|
|
+ initial stack/ram area prior to SDRAM being available. Either
|
|
|
+ option should work for you. Using CS 4 should be fine if your
|
|
|
+ board designers haven't used it for something that would
|
|
|
+ cause you grief during the initial boot! It is frequently not
|
|
|
+ used.
|
|
|
+
|
|
|
+ CFG_INIT_RAM_ADDR should be somewhere that won't interfere
|
|
|
+ with your processor/board/system design. The default value
|
|
|
+ you will find in any recent u-boot distribution in
|
|
|
+ Walnut405.h should work for you. I'd set it to a value larger
|
|
|
+ than your SDRAM module. If you have a 64MB SDRAM module, set
|
|
|
+ it above 400_0000. Just make sure your board has no resources
|
|
|
+ that are supposed to respond to that address! That code in
|
|
|
+ start.S has been around a while and should work as is when
|
|
|
+ you get the config right.
|
|
|
+
|
|
|
+ -Chris Hallinan
|
|
|
+ DS4.COM, Inc.
|
|
|
+
|
|
|
+It is essential to remember this, since it has some impact on the C
|
|
|
+code for the initialization procedures:
|
|
|
+
|
|
|
+* Initialized global data (data segment) is read-only. Do not attempt
|
|
|
+ to write it.
|
|
|
+
|
|
|
+* Do not use any unitialized global data (or implicitely initialized
|
|
|
+ as zero data - BSS segment) at all - this is undefined, initiali-
|
|
|
+ zation is performed later (when relocating to RAM).
|
|
|
+
|
|
|
+* Stack space is very limited. Avoid big data buffers or things like
|
|
|
+ that.
|
|
|
+
|
|
|
+Having only the stack as writable memory limits means we cannot use
|
|
|
+normal global data to share information beween the code. But it
|
|
|
+turned out that the implementation of U-Boot can be greatly
|
|
|
+simplified by making a global data structure (gd_t) available to all
|
|
|
+functions. We could pass a pointer to this data as argument to _all_
|
|
|
+functions, but this would bloat the code. Instead we use a feature of
|
|
|
+the GCC compiler (Global Register Variables) to share the data: we
|
|
|
+place a pointer (gd) to the global data into a register which we
|
|
|
+reserve for this purpose.
|
|
|
+
|
|
|
+When choosing a register for such a purpose we are restricted by the
|
|
|
+relevant (E)ABI specifications for the current architecture, and by
|
|
|
+GCC's implementation.
|
|
|
+
|
|
|
+For PowerPC, the following registers have specific use:
|
|
|
+ R1: stack pointer
|
|
|
+ R2: TOC pointer
|
|
|
+ R3-R4: parameter passing and return values
|
|
|
+ R5-R10: parameter passing
|
|
|
+ R13: small data area pointer
|
|
|
+ R30: GOT pointer
|
|
|
+ R31: frame pointer
|
|
|
+
|
|
|
+ (U-Boot also uses R14 as internal GOT pointer.)
|
|
|
+
|
|
|
+ ==> U-Boot will use R29 to hold a pointer to the global data
|
|
|
+
|
|
|
+ Note: on PPC, we could use a static initializer (since the
|
|
|
+ address of the global data structure is known at compile time),
|
|
|
+ but it turned out that reserving a register results in somewhat
|
|
|
+ smaller code - although the code savings are not that big (on
|
|
|
+ average for all boards 752 bytes for the whole U-Boot image,
|
|
|
+ 624 text + 127 data).
|
|
|
+
|
|
|
+On ARM, the following registers are used:
|
|
|
+
|
|
|
+ R0: function argument word/integer result
|
|
|
+ R1-R3: function argument word
|
|
|
+ R9: GOT pointer
|
|
|
+ R10: stack limit (used only if stack checking if enabled)
|
|
|
+ R11: argument (frame) pointer
|
|
|
+ R12: temporary workspace
|
|
|
+ R13: stack pointer
|
|
|
+ R14: link register
|
|
|
+ R15: program counter
|
|
|
+
|
|
|
+ ==> U-Boot will use R8 to hold a pointer to the global data
|
|
|
+
|
|
|
+
|
|
|
+Memory Management:
|
|
|
+------------------
|
|
|
+
|
|
|
+U-Boot runs in system state and uses physical addresses, i.e. the
|
|
|
+MMU is not used either for address mapping nor for memory protection.
|
|
|
+
|
|
|
+The available memory is mapped to fixed addresses using the memory
|
|
|
+controller. In this process, a contiguous block is formed for each
|
|
|
+memory type (Flash, SDRAM, SRAM), even when it consists of several
|
|
|
+physical memory banks.
|
|
|
+
|
|
|
+U-Boot is installed in the first 128 kB of the first Flash bank (on
|
|
|
+TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
|
|
|
+booting and sizing and initializing DRAM, the code relocates itself
|
|
|
+to the upper end of DRAM. Immediately below the U-Boot code some
|
|
|
+memory is reserved for use by malloc() [see CFG_MALLOC_LEN
|
|
|
+configuration setting]. Below that, a structure with global Board
|
|
|
+Info data is placed, followed by the stack (growing downward).
|
|
|
+
|
|
|
+Additionally, some exception handler code is copied to the low 8 kB
|
|
|
+of DRAM (0x00000000 ... 0x00001FFF).
|
|
|
+
|
|
|
+So a typical memory configuration with 16 MB of DRAM could look like
|
|
|
+this:
|
|
|
+
|
|
|
+ 0x0000 0000 Exception Vector code
|
|
|
+ :
|
|
|
+ 0x0000 1FFF
|
|
|
+ 0x0000 2000 Free for Application Use
|
|
|
+ :
|
|
|
+ :
|
|
|
+
|
|
|
+ :
|
|
|
+ :
|
|
|
+ 0x00FB FF20 Monitor Stack (Growing downward)
|
|
|
+ 0x00FB FFAC Board Info Data and permanent copy of global data
|
|
|
+ 0x00FC 0000 Malloc Arena
|
|
|
+ :
|
|
|
+ 0x00FD FFFF
|
|
|
+ 0x00FE 0000 RAM Copy of Monitor Code
|
|
|
+ ... eventually: LCD or video framebuffer
|
|
|
+ ... eventually: pRAM (Protected RAM - unchanged by reset)
|
|
|
+ 0x00FF FFFF [End of RAM]
|
|
|
+
|
|
|
+
|
|
|
+System Initialization:
|
|
|
+----------------------
|
|
|
|
|
|
- So a typical call to build a U-Boot image would read:
|
|
|
+In the reset configuration, U-Boot starts at the reset entry point
|
|
|
+(on most PowerPC systens at address 0x00000100). Because of the reset
|
|
|
+configuration for CS0# this is a mirror of the onboard Flash memory.
|
|
|
+To be able to re-map memory U-Boot then jumps to its link address.
|
|
|
+To be able to implement the initialization code in C, a (small!)
|
|
|
+initial stack is set up in the internal Dual Ported RAM (in case CPUs
|
|
|
+which provide such a feature like MPC8xx or MPC8260), or in a locked
|
|
|
+part of the data cache. After that, U-Boot initializes the CPU core,
|
|
|
+the caches and the SIU.
|
|
|
+
|
|
|
+Next, all (potentially) available memory banks are mapped using a
|
|
|
+preliminary mapping. For example, we put them on 512 MB boundaries
|
|
|
+(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
|
|
|
+on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
|
|
|
+programmed for SDRAM access. Using the temporary configuration, a
|
|
|
+simple memory test is run that determines the size of the SDRAM
|
|
|
+banks.
|
|
|
+
|
|
|
+When there is more than one SDRAM bank, and the banks are of
|
|
|
+different size, the largest is mapped first. For equal size, the first
|
|
|
+bank (CS2#) is mapped first. The first mapping is always for address
|
|
|
+0x00000000, with any additional banks following immediately to create
|
|
|
+contiguous memory starting from 0.
|
|
|
+
|
|
|
+Then, the monitor installs itself at the upper end of the SDRAM area
|
|
|
+and allocates memory for use by malloc() and for the global Board
|
|
|
+Info data; also, the exception vector code is copied to the low RAM
|
|
|
+pages, and the final stack is set up.
|
|
|
+
|
|
|
+Only after this relocation will you have a "normal" C environment;
|
|
|
+until that you are restricted in several ways, mostly because you are
|
|
|
+running from ROM, and because the code will have to be relocated to a
|
|
|
+new address in RAM.
|
|
|
+
|
|
|
+
|
|
|
+U-Boot Porting Guide:
|
|
|
+----------------------
|
|
|
|
|
|
- -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
|
|
|
- > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
|
|
|
- > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
|
|
|
- > examples/uImage.TQM850L
|
|
|
- Image Name: 2.4.4 kernel for TQM850L
|
|
|
- Created: Wed Jul 19 02:34:59 2000
|
|
|
- Image Type: PowerPC Linux Kernel Image (gzip compressed)
|
|
|
- Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
|
|
|
- Load Address: 0x00000000
|
|
|
- Entry Point: 0x00000000
|
|
|
+[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
|
|
|
+list, October 2002]
|
|
|
|
|
|
- To verify the contents of the image (or check for corruption):
|
|
|
|
|
|
- -> tools/mkimage -l examples/uImage.TQM850L
|
|
|
- Image Name: 2.4.4 kernel for TQM850L
|
|
|
- Created: Wed Jul 19 02:34:59 2000
|
|
|
- Image Type: PowerPC Linux Kernel Image (gzip compressed)
|
|
|
- Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
|
|
|
- Load Address: 0x00000000
|
|
|
- Entry Point: 0x00000000
|
|
|
+int main (int argc, char *argv[])
|
|
|
+{
|
|
|
+ sighandler_t no_more_time;
|
|
|
|
|
|
- NOTE: for embedded systems where boot time is critical you can trade
|
|
|
- speed for memory and install an UNCOMPRESSED image instead: this
|
|
|
- needs more space in Flash, but boots much faster since it does not
|
|
|
- need to be uncompressed:
|
|
|
-
|
|
|
- -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
|
|
|
- -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
|
|
|
- > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
|
|
|
- > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
|
|
|
- > examples/uImage.TQM850L-uncompressed
|
|
|
- Image Name: 2.4.4 kernel for TQM850L
|
|
|
- Created: Wed Jul 19 02:34:59 2000
|
|
|
- Image Type: PowerPC Linux Kernel Image (uncompressed)
|
|
|
- Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
|
|
|
- Load Address: 0x00000000
|
|
|
- Entry Point: 0x00000000
|
|
|
-
|
|
|
-
|
|
|
- Similar you can build U-Boot images from a 'ramdisk.image.gz' file
|
|
|
- when your kernel is intended to use an initial ramdisk:
|
|
|
-
|
|
|
- -> tools/mkimage -n 'Simple Ramdisk Image' \
|
|
|
- > -A ppc -O linux -T ramdisk -C gzip \
|
|
|
- > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
|
|
|
- Image Name: Simple Ramdisk Image
|
|
|
- Created: Wed Jan 12 14:01:50 2000
|
|
|
- Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
|
|
|
- Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
|
|
|
- Load Address: 0x00000000
|
|
|
- Entry Point: 0x00000000
|
|
|
-
|
|
|
-
|
|
|
- Installing a Linux Image:
|
|
|
- -------------------------
|
|
|
-
|
|
|
- To downloading a U-Boot image over the serial (console) interface,
|
|
|
- you must convert the image to S-Record format:
|
|
|
-
|
|
|
- objcopy -I binary -O srec examples/image examples/image.srec
|
|
|
-
|
|
|
- The 'objcopy' does not understand the information in the U-Boot
|
|
|
- image header, so the resulting S-Record file will be relative to
|
|
|
- address 0x00000000. To load it to a given address, you need to
|
|
|
- specify the target address as 'offset' parameter with the 'loads'
|
|
|
- command.
|
|
|
-
|
|
|
- Example: install the image to address 0x40100000 (which on the
|
|
|
- TQM8xxL is in the first Flash bank):
|
|
|
-
|
|
|
- => erase 40100000 401FFFFF
|
|
|
-
|
|
|
- .......... done
|
|
|
- Erased 8 sectors
|
|
|
-
|
|
|
- => loads 40100000
|
|
|
- ## Ready for S-Record download ...
|
|
|
- ~>examples/image.srec
|
|
|
- 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
|
|
|
- ...
|
|
|
- 15989 15990 15991 15992
|
|
|
- [file transfer complete]
|
|
|
- [connected]
|
|
|
- ## Start Addr = 0x00000000
|
|
|
-
|
|
|
-
|
|
|
- You can check the success of the download using the 'iminfo' command;
|
|
|
- this includes a checksum verification so you can be sure no data
|
|
|
- corruption happened:
|
|
|
-
|
|
|
- => imi 40100000
|
|
|
-
|
|
|
- ## Checking Image at 40100000 ...
|
|
|
- Image Name: 2.2.13 for initrd on TQM850L
|
|
|
- Image Type: PowerPC Linux Kernel Image (gzip compressed)
|
|
|
- Data Size: 335725 Bytes = 327 kB = 0 MB
|
|
|
- Load Address: 00000000
|
|
|
- Entry Point: 0000000c
|
|
|
- Verifying Checksum ... OK
|
|
|
-
|
|
|
-
|
|
|
- Boot Linux:
|
|
|
- -----------
|
|
|
-
|
|
|
- The "bootm" command is used to boot an application that is stored in
|
|
|
- memory (RAM or Flash). In case of a Linux kernel image, the contents
|
|
|
- of the "bootargs" environment variable is passed to the kernel as
|
|
|
- parameters. You can check and modify this variable using the
|
|
|
- "printenv" and "setenv" commands:
|
|
|
-
|
|
|
-
|
|
|
- => printenv bootargs
|
|
|
- bootargs=root=/dev/ram
|
|
|
-
|
|
|
- => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
|
|
|
-
|
|
|
- => printenv bootargs
|
|
|
- bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
|
|
|
-
|
|
|
- => bootm 40020000
|
|
|
- ## Booting Linux kernel at 40020000 ...
|
|
|
- Image Name: 2.2.13 for NFS on TQM850L
|
|
|
- Image Type: PowerPC Linux Kernel Image (gzip compressed)
|
|
|
- Data Size: 381681 Bytes = 372 kB = 0 MB
|
|
|
- Load Address: 00000000
|
|
|
- Entry Point: 0000000c
|
|
|
- Verifying Checksum ... OK
|
|
|
- Uncompressing Kernel Image ... OK
|
|
|
- Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
|
|
|
- Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
|
|
|
- time_init: decrementer frequency = 187500000/60
|
|
|
- Calibrating delay loop... 49.77 BogoMIPS
|
|
|
- Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
|
|
|
- ...
|
|
|
-
|
|
|
- If you want to boot a Linux kernel with initial ram disk, you pass
|
|
|
- the memory addresses of both the kernel and the initrd image (PPBCOOT
|
|
|
- format!) to the "bootm" command:
|
|
|
-
|
|
|
- => imi 40100000 40200000
|
|
|
-
|
|
|
- ## Checking Image at 40100000 ...
|
|
|
- Image Name: 2.2.13 for initrd on TQM850L
|
|
|
- Image Type: PowerPC Linux Kernel Image (gzip compressed)
|
|
|
- Data Size: 335725 Bytes = 327 kB = 0 MB
|
|
|
- Load Address: 00000000
|
|
|
- Entry Point: 0000000c
|
|
|
- Verifying Checksum ... OK
|
|
|
-
|
|
|
- ## Checking Image at 40200000 ...
|
|
|
- Image Name: Simple Ramdisk Image
|
|
|
- Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
|
|
|
- Data Size: 566530 Bytes = 553 kB = 0 MB
|
|
|
- Load Address: 00000000
|
|
|
- Entry Point: 00000000
|
|
|
- Verifying Checksum ... OK
|
|
|
-
|
|
|
- => bootm 40100000 40200000
|
|
|
- ## Booting Linux kernel at 40100000 ...
|
|
|
- Image Name: 2.2.13 for initrd on TQM850L
|
|
|
- Image Type: PowerPC Linux Kernel Image (gzip compressed)
|
|
|
- Data Size: 335725 Bytes = 327 kB = 0 MB
|
|
|
- Load Address: 00000000
|
|
|
- Entry Point: 0000000c
|
|
|
- Verifying Checksum ... OK
|
|
|
- Uncompressing Kernel Image ... OK
|
|
|
- ## Loading RAMDisk Image at 40200000 ...
|
|
|
- Image Name: Simple Ramdisk Image
|
|
|
- Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
|
|
|
- Data Size: 566530 Bytes = 553 kB = 0 MB
|
|
|
- Load Address: 00000000
|
|
|
- Entry Point: 00000000
|
|
|
- Verifying Checksum ... OK
|
|
|
- Loading Ramdisk ... OK
|
|
|
- Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
|
|
|
- Boot arguments: root=/dev/ram
|
|
|
- time_init: decrementer frequency = 187500000/60
|
|
|
- Calibrating delay loop... 49.77 BogoMIPS
|
|
|
- ...
|
|
|
- RAMDISK: Compressed image found at block 0
|
|
|
- VFS: Mounted root (ext2 filesystem).
|
|
|
-
|
|
|
- bash#
|
|
|
-
|
|
|
- More About U-Boot Image Types:
|
|
|
- ------------------------------
|
|
|
-
|
|
|
- U-Boot supports the following image types:
|
|
|
-
|
|
|
- "Standalone Programs" are directly runnable in the environment
|
|
|
- provided by U-Boot; it is expected that (if they behave
|
|
|
- well) you can continue to work in U-Boot after return from
|
|
|
- the Standalone Program.
|
|
|
- "OS Kernel Images" are usually images of some Embedded OS which
|
|
|
- will take over control completely. Usually these programs
|
|
|
- will install their own set of exception handlers, device
|
|
|
- drivers, set up the MMU, etc. - this means, that you cannot
|
|
|
- expect to re-enter U-Boot except by resetting the CPU.
|
|
|
- "RAMDisk Images" are more or less just data blocks, and their
|
|
|
- parameters (address, size) are passed to an OS kernel that is
|
|
|
- being started.
|
|
|
- "Multi-File Images" contain several images, typically an OS
|
|
|
- (Linux) kernel image and one or more data images like
|
|
|
- RAMDisks. This construct is useful for instance when you want
|
|
|
- to boot over the network using BOOTP etc., where the boot
|
|
|
- server provides just a single image file, but you want to get
|
|
|
- for instance an OS kernel and a RAMDisk image.
|
|
|
-
|
|
|
- "Multi-File Images" start with a list of image sizes, each
|
|
|
- image size (in bytes) specified by an "uint32_t" in network
|
|
|
- byte order. This list is terminated by an "(uint32_t)0".
|
|
|
- Immediately after the terminating 0 follow the images, one by
|
|
|
- one, all aligned on "uint32_t" boundaries (size rounded up to
|
|
|
- a multiple of 4 bytes).
|
|
|
-
|
|
|
- "Firmware Images" are binary images containing firmware (like
|
|
|
- U-Boot or FPGA images) which usually will be programmed to
|
|
|
- flash memory.
|
|
|
-
|
|
|
- "Script files" are command sequences that will be executed by
|
|
|
- U-Boot's command interpreter; this feature is especially
|
|
|
- useful when you configure U-Boot to use a real shell (hush)
|
|
|
- as command interpreter.
|
|
|
-
|
|
|
-
|
|
|
- Standalone HOWTO:
|
|
|
- =================
|
|
|
-
|
|
|
- One of the features of U-Boot is that you can dynamically load and
|
|
|
- run "standalone" applications, which can use some resources of
|
|
|
- U-Boot like console I/O functions or interrupt services.
|
|
|
-
|
|
|
- Two simple examples are included with the sources:
|
|
|
-
|
|
|
- "Hello World" Demo:
|
|
|
- -------------------
|
|
|
-
|
|
|
- 'examples/hello_world.c' contains a small "Hello World" Demo
|
|
|
- application; it is automatically compiled when you build U-Boot.
|
|
|
- It's configured to run at address 0x00040004, so you can play with it
|
|
|
- like that:
|
|
|
-
|
|
|
- => loads
|
|
|
- ## Ready for S-Record download ...
|
|
|
- ~>examples/hello_world.srec
|
|
|
- 1 2 3 4 5 6 7 8 9 10 11 ...
|
|
|
- [file transfer complete]
|
|
|
- [connected]
|
|
|
- ## Start Addr = 0x00040004
|
|
|
-
|
|
|
- => go 40004 Hello World! This is a test.
|
|
|
- ## Starting application at 0x00040004 ...
|
|
|
- Hello World
|
|
|
- argc = 7
|
|
|
- argv[0] = "40004"
|
|
|
- argv[1] = "Hello"
|
|
|
- argv[2] = "World!"
|
|
|
- argv[3] = "This"
|
|
|
- argv[4] = "is"
|
|
|
- argv[5] = "a"
|
|
|
- argv[6] = "test."
|
|
|
- argv[7] = "<NULL>"
|
|
|
- Hit any key to exit ...
|
|
|
-
|
|
|
- ## Application terminated, rc = 0x0
|
|
|
-
|
|
|
- Another example, which demonstrates how to register a CPM interrupt
|
|
|
- handler with the U-Boot code, can be found in 'examples/timer.c'.
|
|
|
- Here, a CPM timer is set up to generate an interrupt every second.
|
|
|
- The interrupt service routine is trivial, just printing a '.'
|
|
|
- character, but this is just a demo program. The application can be
|
|
|
- controlled by the following keys:
|
|
|
-
|
|
|
- ? - print current values og the CPM Timer registers
|
|
|
- b - enable interrupts and start timer
|
|
|
- e - stop timer and disable interrupts
|
|
|
- q - quit application
|
|
|
-
|
|
|
- => loads
|
|
|
- ## Ready for S-Record download ...
|
|
|
- ~>examples/timer.srec
|
|
|
- 1 2 3 4 5 6 7 8 9 10 11 ...
|
|
|
- [file transfer complete]
|
|
|
- [connected]
|
|
|
- ## Start Addr = 0x00040004
|
|
|
-
|
|
|
- => go 40004
|
|
|
- ## Starting application at 0x00040004 ...
|
|
|
- TIMERS=0xfff00980
|
|
|
- Using timer 1
|
|
|
- tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
|
|
|
-
|
|
|
- Hit 'b':
|
|
|
- [q, b, e, ?] Set interval 1000000 us
|
|
|
- Enabling timer
|
|
|
- Hit '?':
|
|
|
- [q, b, e, ?] ........
|
|
|
- tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
|
|
|
- Hit '?':
|
|
|
- [q, b, e, ?] .
|
|
|
- tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
|
|
|
- Hit '?':
|
|
|
- [q, b, e, ?] .
|
|
|
- tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
|
|
|
- Hit '?':
|
|
|
- [q, b, e, ?] .
|
|
|
- tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
|
|
|
- Hit 'e':
|
|
|
- [q, b, e, ?] ...Stopping timer
|
|
|
- Hit 'q':
|
|
|
- [q, b, e, ?] ## Application terminated, rc = 0x0
|
|
|
-
|
|
|
-
|
|
|
- Minicom warning:
|
|
|
- ================
|
|
|
-
|
|
|
- Over time, many people have reported problems when trying to use the
|
|
|
- "minicom" terminal emulation program for serial download. I (wd)
|
|
|
- consider minicom to be broken, and recommend not to use it. Under
|
|
|
- Unix, I recommend to use C-Kermit for general purpose use (and
|
|
|
- especially for kermit binary protocol download ("loadb" command), and
|
|
|
- use "cu" for S-Record download ("loads" command).
|
|
|
-
|
|
|
- Nevertheless, if you absolutely want to use it try adding this
|
|
|
- configuration to your "File transfer protocols" section:
|
|
|
-
|
|
|
- Name Program Name U/D FullScr IO-Red. Multi
|
|
|
- X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
|
|
|
- Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
|
|
|
-
|
|
|
-
|
|
|
- NetBSD Notes:
|
|
|
- =============
|
|
|
-
|
|
|
- Starting at version 0.9.2, U-Boot supports NetBSD both as host
|
|
|
- (build U-Boot) and target system (boots NetBSD/mpc8xx).
|
|
|
-
|
|
|
- Building requires a cross environment; it is known to work on
|
|
|
- NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
|
|
|
- need gmake since the Makefiles are not compatible with BSD make).
|
|
|
- Note that the cross-powerpc package does not install include files;
|
|
|
- attempting to build U-Boot will fail because <machine/ansi.h> is
|
|
|
- missing. This file has to be installed and patched manually:
|
|
|
-
|
|
|
- # cd /usr/pkg/cross/powerpc-netbsd/include
|
|
|
- # mkdir powerpc
|
|
|
- # ln -s powerpc machine
|
|
|
- # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
|
|
|
- # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
|
|
|
-
|
|
|
- Native builds *don't* work due to incompatibilities between native
|
|
|
- and U-Boot include files.
|
|
|
-
|
|
|
- Booting assumes that (the first part of) the image booted is a
|
|
|
- stage-2 loader which in turn loads and then invokes the kernel
|
|
|
- proper. Loader sources will eventually appear in the NetBSD source
|
|
|
- tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
|
|
|
- meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for
|
|
|
- details.
|
|
|
-
|
|
|
-
|
|
|
- Implementation Internals:
|
|
|
- =========================
|
|
|
-
|
|
|
- The following is not intended to be a complete description of every
|
|
|
- implementation detail. However, it should help to understand the
|
|
|
- inner workings of U-Boot and make it easier to port it to custom
|
|
|
- hardware.
|
|
|
-
|
|
|
-
|
|
|
- Initial Stack, Global Data:
|
|
|
- ---------------------------
|
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-
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- The implementation of U-Boot is complicated by the fact that U-Boot
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- starts running out of ROM (flash memory), usually without access to
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- system RAM (because the memory controller is not initialized yet).
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- This means that we don't have writable Data or BSS segments, and BSS
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- is not initialized as zero. To be able to get a C environment working
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- at all, we have to allocate at least a minimal stack. Implementation
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- options for this are defined and restricted by the CPU used: Some CPU
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- models provide on-chip memory (like the IMMR area on MPC8xx and
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- MPC826x processors), on others (parts of) the data cache can be
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- locked as (mis-) used as memory, etc.
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-
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- Chris Hallinan posted a good summary of these issues to the
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- u-boot-users mailing list:
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-
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- Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
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- From: "Chris Hallinan" <clh@net1plus.com>
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- Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
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- ...
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-
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- Correct me if I'm wrong, folks, but the way I understand it
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- is this: Using DCACHE as initial RAM for Stack, etc, does not
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- require any physical RAM backing up the cache. The cleverness
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- is that the cache is being used as a temporary supply of
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- necessary storage before the SDRAM controller is setup. It's
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- beyond the scope of this list to expain the details, but you
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- can see how this works by studying the cache architecture and
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- operation in the architecture and processor-specific manuals.
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-
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- OCM is On Chip Memory, which I believe the 405GP has 4K. It
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- is another option for the system designer to use as an
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- initial stack/ram area prior to SDRAM being available. Either
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- option should work for you. Using CS 4 should be fine if your
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- board designers haven't used it for something that would
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- cause you grief during the initial boot! It is frequently not
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- used.
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-
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- CFG_INIT_RAM_ADDR should be somewhere that won't interfere
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- with your processor/board/system design. The default value
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- you will find in any recent u-boot distribution in
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- Walnut405.h should work for you. I'd set it to a value larger
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- than your SDRAM module. If you have a 64MB SDRAM module, set
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- it above 400_0000. Just make sure your board has no resources
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- that are supposed to respond to that address! That code in
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- start.S has been around a while and should work as is when
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- you get the config right.
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-
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- -Chris Hallinan
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- DS4.COM, Inc.
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-
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- It is essential to remember this, since it has some impact on the C
|
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- code for the initialization procedures:
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-
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- * Initialized global data (data segment) is read-only. Do not attempt
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- to write it.
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-
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- * Do not use any unitialized global data (or implicitely initialized
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- as zero data - BSS segment) at all - this is undefined, initiali-
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- zation is performed later (when relocating to RAM).
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-
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- * Stack space is very limited. Avoid big data buffers or things like
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- that.
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-
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- Having only the stack as writable memory limits means we cannot use
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- normal global data to share information beween the code. But it
|
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- turned out that the implementation of U-Boot can be greatly
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- simplified by making a global data structure (gd_t) available to all
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- functions. We could pass a pointer to this data as argument to _all_
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- functions, but this would bloat the code. Instead we use a feature of
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|
- the GCC compiler (Global Register Variables) to share the data: we
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- place a pointer (gd) to the global data into a register which we
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- reserve for this purpose.
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-
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- When choosing a register for such a purpose we are restricted by the
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|
- relevant (E)ABI specifications for the current architecture, and by
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|
- GCC's implementation.
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-
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- For PowerPC, the following registers have specific use:
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- R1: stack pointer
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|
- R2: TOC pointer
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- R3-R4: parameter passing and return values
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|
- R5-R10: parameter passing
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- R13: small data area pointer
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- R30: GOT pointer
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- R31: frame pointer
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-
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- (U-Boot also uses R14 as internal GOT pointer.)
|
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-
|
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- ==> U-Boot will use R29 to hold a pointer to the global data
|
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-
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- Note: on PPC, we could use a static initializer (since the
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|
|
- address of the global data structure is known at compile time),
|
|
|
- but it turned out that reserving a register results in somewhat
|
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|
- smaller code - although the code savings are not that big (on
|
|
|
- average for all boards 752 bytes for the whole U-Boot image,
|
|
|
- 624 text + 127 data).
|
|
|
-
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|
- On ARM, the following registers are used:
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-
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- R0: function argument word/integer result
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|
- R1-R3: function argument word
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|
- R9: GOT pointer
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|
- R10: stack limit (used only if stack checking if enabled)
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|
- R11: argument (frame) pointer
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|
|
- R12: temporary workspace
|
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|
- R13: stack pointer
|
|
|
- R14: link register
|
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|
- R15: program counter
|
|
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-
|
|
|
- ==> U-Boot will use R8 to hold a pointer to the global data
|
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-
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|
-
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|
- Memory Management:
|
|
|
- ------------------
|
|
|
-
|
|
|
- U-Boot runs in system state and uses physical addresses, i.e. the
|
|
|
- MMU is not used either for address mapping nor for memory protection.
|
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|
-
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|
|
- The available memory is mapped to fixed addresses using the memory
|
|
|
- controller. In this process, a contiguous block is formed for each
|
|
|
- memory type (Flash, SDRAM, SRAM), even when it consists of several
|
|
|
- physical memory banks.
|
|
|
-
|
|
|
- U-Boot is installed in the first 128 kB of the first Flash bank (on
|
|
|
- TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
|
|
|
- booting and sizing and initializing DRAM, the code relocates itself
|
|
|
- to the upper end of DRAM. Immediately below the U-Boot code some
|
|
|
- memory is reserved for use by malloc() [see CFG_MALLOC_LEN
|
|
|
- configuration setting]. Below that, a structure with global Board
|
|
|
- Info data is placed, followed by the stack (growing downward).
|
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-
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|
|
- Additionally, some exception handler code is copied to the low 8 kB
|
|
|
- of DRAM (0x00000000 ... 0x00001FFF).
|
|
|
-
|
|
|
- So a typical memory configuration with 16 MB of DRAM could look like
|
|
|
- this:
|
|
|
-
|
|
|
- 0x0000 0000 Exception Vector code
|
|
|
- :
|
|
|
- 0x0000 1FFF
|
|
|
- 0x0000 2000 Free for Application Use
|
|
|
- :
|
|
|
- :
|
|
|
-
|
|
|
- :
|
|
|
- :
|
|
|
- 0x00FB FF20 Monitor Stack (Growing downward)
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|
|
- 0x00FB FFAC Board Info Data and permanent copy of global data
|
|
|
- 0x00FC 0000 Malloc Arena
|
|
|
- :
|
|
|
- 0x00FD FFFF
|
|
|
- 0x00FE 0000 RAM Copy of Monitor Code
|
|
|
- ... eventually: LCD or video framebuffer
|
|
|
- ... eventually: pRAM (Protected RAM - unchanged by reset)
|
|
|
- 0x00FF FFFF [End of RAM]
|
|
|
-
|
|
|
-
|
|
|
- System Initialization:
|
|
|
- ----------------------
|
|
|
-
|
|
|
- In the reset configuration, U-Boot starts at the reset entry point
|
|
|
- (on most PowerPC systens at address 0x00000100). Because of the reset
|
|
|
- configuration for CS0# this is a mirror of the onboard Flash memory.
|
|
|
- To be able to re-map memory U-Boot then jumps to its link address.
|
|
|
- To be able to implement the initialization code in C, a (small!)
|
|
|
- initial stack is set up in the internal Dual Ported RAM (in case CPUs
|
|
|
- which provide such a feature like MPC8xx or MPC8260), or in a locked
|
|
|
- part of the data cache. After that, U-Boot initializes the CPU core,
|
|
|
- the caches and the SIU.
|
|
|
-
|
|
|
- Next, all (potentially) available memory banks are mapped using a
|
|
|
- preliminary mapping. For example, we put them on 512 MB boundaries
|
|
|
- (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
|
|
|
- on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
|
|
|
- programmed for SDRAM access. Using the temporary configuration, a
|
|
|
- simple memory test is run that determines the size of the SDRAM
|
|
|
- banks.
|
|
|
-
|
|
|
- When there is more than one SDRAM bank, and the banks are of
|
|
|
- different size, the largest is mapped first. For equal size, the first
|
|
|
- bank (CS2#) is mapped first. The first mapping is always for address
|
|
|
- 0x00000000, with any additional banks following immediately to create
|
|
|
- contiguous memory starting from 0.
|
|
|
-
|
|
|
- Then, the monitor installs itself at the upper end of the SDRAM area
|
|
|
- and allocates memory for use by malloc() and for the global Board
|
|
|
- Info data; also, the exception vector code is copied to the low RAM
|
|
|
- pages, and the final stack is set up.
|
|
|
-
|
|
|
- Only after this relocation will you have a "normal" C environment;
|
|
|
- until that you are restricted in several ways, mostly because you are
|
|
|
- running from ROM, and because the code will have to be relocated to a
|
|
|
- new address in RAM.
|
|
|
-
|
|
|
-
|
|
|
- U-Boot Porting Guide:
|
|
|
- ----------------------
|
|
|
-
|
|
|
- [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
|
|
|
- list, October 2002]
|
|
|
-
|
|
|
-
|
|
|
- int main (int argc, char *argv[])
|
|
|
- {
|
|
|
- sighandler_t no_more_time;
|
|
|
-
|
|
|
- signal (SIGALRM, no_more_time);
|
|
|
- alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
|
|
|
-
|
|
|
- if (available_money > available_manpower) {
|
|
|
- pay consultant to port U-Boot;
|
|
|
- return 0;
|
|
|
- }
|
|
|
-
|
|
|
- Download latest U-Boot source;
|
|
|
-
|
|
|
- Subscribe to u-boot-users mailing list;
|
|
|
-
|
|
|
- if (clueless) {
|
|
|
- email ("Hi, I am new to U-Boot, how do I get started?");
|
|
|
- }
|
|
|
-
|
|
|
- while (learning) {
|
|
|
- Read the README file in the top level directory;
|
|
|
- Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
|
|
|
- Read the source, Luke;
|
|
|
- }
|
|
|
-
|
|
|
- if (available_money > toLocalCurrency ($2500)) {
|
|
|
- Buy a BDI2000;
|
|
|
- } else {
|
|
|
- Add a lot of aggravation and time;
|
|
|
- }
|
|
|
-
|
|
|
- Create your own board support subdirectory;
|
|
|
-
|
|
|
- Create your own board config file;
|
|
|
-
|
|
|
- while (!running) {
|
|
|
- do {
|
|
|
- Add / modify source code;
|
|
|
- } until (compiles);
|
|
|
- Debug;
|
|
|
- if (clueless)
|
|
|
- email ("Hi, I am having problems...");
|
|
|
- }
|
|
|
- Send patch file to Wolfgang;
|
|
|
+ signal (SIGALRM, no_more_time);
|
|
|
+ alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
|
|
|
|
|
|
+ if (available_money > available_manpower) {
|
|
|
+ pay consultant to port U-Boot;
|
|
|
return 0;
|
|
|
}
|
|
|
|
|
|
- void no_more_time (int sig)
|
|
|
- {
|
|
|
- hire_a_guru();
|
|
|
+ Download latest U-Boot source;
|
|
|
+
|
|
|
+ Subscribe to u-boot-users mailing list;
|
|
|
+
|
|
|
+ if (clueless) {
|
|
|
+ email ("Hi, I am new to U-Boot, how do I get started?");
|
|
|
+ }
|
|
|
+
|
|
|
+ while (learning) {
|
|
|
+ Read the README file in the top level directory;
|
|
|
+ Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
|
|
|
+ Read the source, Luke;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (available_money > toLocalCurrency ($2500)) {
|
|
|
+ Buy a BDI2000;
|
|
|
+ } else {
|
|
|
+ Add a lot of aggravation and time;
|
|
|
}
|
|
|
|
|
|
+ Create your own board support subdirectory;
|
|
|
+
|
|
|
+ Create your own board config file;
|
|
|
+
|
|
|
+ while (!running) {
|
|
|
+ do {
|
|
|
+ Add / modify source code;
|
|
|
+ } until (compiles);
|
|
|
+ Debug;
|
|
|
+ if (clueless)
|
|
|
+ email ("Hi, I am having problems...");
|
|
|
+ }
|
|
|
+ Send patch file to Wolfgang;
|
|
|
+
|
|
|
+ return 0;
|
|
|
+}
|
|
|
+
|
|
|
+void no_more_time (int sig)
|
|
|
+{
|
|
|
+ hire_a_guru();
|
|
|
+}
|
|
|
+
|
|
|
|
|
|
- Coding Standards:
|
|
|
- -----------------
|
|
|
+Coding Standards:
|
|
|
+-----------------
|
|
|
|
|
|
- All contributions to U-Boot should conform to the Linux kernel
|
|
|
- coding style; see the file "Documentation/CodingStyle" in your Linux
|
|
|
- kernel source directory.
|
|
|
+All contributions to U-Boot should conform to the Linux kernel
|
|
|
+coding style; see the file "Documentation/CodingStyle" in your Linux
|
|
|
+kernel source directory.
|
|
|
|
|
|
- Please note that U-Boot is implemented in C (and to some small parts
|
|
|
- in Assembler); no C++ is used, so please do not use C++ style
|
|
|
- comments (//) in your code.
|
|
|
+Please note that U-Boot is implemented in C (and to some small parts
|
|
|
+in Assembler); no C++ is used, so please do not use C++ style
|
|
|
+comments (//) in your code.
|
|
|
|
|
|
- Please also stick to the following formatting rules:
|
|
|
- - remove any trailing white space
|
|
|
- - use TAB characters for indentation, not spaces
|
|
|
- - make sure NOT to use DOS '\r\n' line feeds
|
|
|
- - do not add more than 2 empty lines to source files
|
|
|
- - do not add trailing empty lines to source files
|
|
|
+Please also stick to the following formatting rules:
|
|
|
+- remove any trailing white space
|
|
|
+- use TAB characters for indentation, not spaces
|
|
|
+- make sure NOT to use DOS '\r\n' line feeds
|
|
|
+- do not add more than 2 empty lines to source files
|
|
|
+- do not add trailing empty lines to source files
|
|
|
|
|
|
- Submissions which do not conform to the standards may be returned
|
|
|
- with a request to reformat the changes.
|
|
|
+Submissions which do not conform to the standards may be returned
|
|
|
+with a request to reformat the changes.
|
|
|
|
|
|
|
|
|
- Submitting Patches:
|
|
|
- -------------------
|
|
|
+Submitting Patches:
|
|
|
+-------------------
|
|
|
|
|
|
- Since the number of patches for U-Boot is growing, we need to
|
|
|
- establish some rules. Submissions which do not conform to these rules
|
|
|
- may be rejected, even when they contain important and valuable stuff.
|
|
|
+Since the number of patches for U-Boot is growing, we need to
|
|
|
+establish some rules. Submissions which do not conform to these rules
|
|
|
+may be rejected, even when they contain important and valuable stuff.
|
|
|
|
|
|
|
|
|
- When you send a patch, please include the following information with
|
|
|
- it:
|
|
|
+When you send a patch, please include the following information with
|
|
|
+it:
|
|
|
|
|
|
- * For bug fixes: a description of the bug and how your patch fixes
|
|
|
- this bug. Please try to include a way of demonstrating that the
|
|
|
- patch actually fixes something.
|
|
|
+* For bug fixes: a description of the bug and how your patch fixes
|
|
|
+ this bug. Please try to include a way of demonstrating that the
|
|
|
+ patch actually fixes something.
|
|
|
|
|
|
- * For new features: a description of the feature and your
|
|
|
- implementation.
|
|
|
+* For new features: a description of the feature and your
|
|
|
+ implementation.
|
|
|
|
|
|
- * A CHANGELOG entry as plaintext (separate from the patch)
|
|
|
+* A CHANGELOG entry as plaintext (separate from the patch)
|
|
|
|
|
|
- * For major contributions, your entry to the CREDITS file
|
|
|
+* For major contributions, your entry to the CREDITS file
|
|
|
|
|
|
- * When you add support for a new board, don't forget to add this
|
|
|
- board to the MAKEALL script, too.
|
|
|
+* When you add support for a new board, don't forget to add this
|
|
|
+ board to the MAKEALL script, too.
|
|
|
|
|
|
- * If your patch adds new configuration options, don't forget to
|
|
|
- document these in the README file.
|
|
|
+* If your patch adds new configuration options, don't forget to
|
|
|
+ document these in the README file.
|
|
|
|
|
|
- * The patch itself. If you are accessing the CVS repository use "cvs
|
|
|
- update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
|
|
|
- version of diff does not support these options, then get the latest
|
|
|
- version of GNU diff.
|
|
|
+* The patch itself. If you are accessing the CVS repository use "cvs
|
|
|
+ update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
|
|
|
+ version of diff does not support these options, then get the latest
|
|
|
+ version of GNU diff.
|
|
|
|
|
|
- The current directory when running this command shall be the top
|
|
|
- level directory of the U-Boot source tree, or it's parent directory
|
|
|
- (i. e. please make sure that your patch includes sufficient
|
|
|
- directory information for the affected files).
|
|
|
+ The current directory when running this command shall be the top
|
|
|
+ level directory of the U-Boot source tree, or it's parent directory
|
|
|
+ (i. e. please make sure that your patch includes sufficient
|
|
|
+ directory information for the affected files).
|
|
|
|
|
|
- We accept patches as plain text, MIME attachments or as uuencoded
|
|
|
- gzipped text.
|
|
|
+ We accept patches as plain text, MIME attachments or as uuencoded
|
|
|
+ gzipped text.
|
|
|
|
|
|
- * If one logical set of modifications affects or creates several
|
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|
- files, all these changes shall be submitted in a SINGLE patch file.
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+* If one logical set of modifications affects or creates several
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+ files, all these changes shall be submitted in a SINGLE patch file.
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- * Changesets that contain different, unrelated modifications shall be
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- submitted as SEPARATE patches, one patch per changeset.
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+* Changesets that contain different, unrelated modifications shall be
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+ submitted as SEPARATE patches, one patch per changeset.
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- Notes:
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+Notes:
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- * Before sending the patch, run the MAKEALL script on your patched
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- source tree and make sure that no errors or warnings are reported
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- for any of the boards.
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+* Before sending the patch, run the MAKEALL script on your patched
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+ source tree and make sure that no errors or warnings are reported
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+ for any of the boards.
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- * Keep your modifications to the necessary minimum: A patch
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- containing several unrelated changes or arbitrary reformats will be
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- returned with a request to re-formatting / split it.
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+* Keep your modifications to the necessary minimum: A patch
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+ containing several unrelated changes or arbitrary reformats will be
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+ returned with a request to re-formatting / split it.
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- * If you modify existing code, make sure that your new code does not
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- add to the memory footprint of the code ;-) Small is beautiful!
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- When adding new features, these should compile conditionally only
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- (using #ifdef), and the resulting code with the new feature
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- disabled must not need more memory than the old code without your
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- modification.
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+* If you modify existing code, make sure that your new code does not
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+ add to the memory footprint of the code ;-) Small is beautiful!
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+ When adding new features, these should compile conditionally only
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+ (using #ifdef), and the resulting code with the new feature
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+ disabled must not need more memory than the old code without your
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+ modification.
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wdenk