|
@@ -24,13 +24,14 @@
|
|
|
Summary:
|
|
|
========
|
|
|
|
|
|
-This directory contains the source code for U-Boot, a monitor for
|
|
|
-Embedded PowerPC boards, which can be installed in a boot ROM and
|
|
|
-used to test the hardware or download and run application code.
|
|
|
+This directory contains the source code for U-Boot, a boot loader for
|
|
|
+Embedded boards based on PowerPC and ARM processors, which can be
|
|
|
+installed in a boot ROM and used to initialize and test the hardware
|
|
|
+or to download and run application code.
|
|
|
|
|
|
The development of U-Boot is closely related to Linux: some parts of
|
|
|
-the source code originate in the Linux source tree, we still have
|
|
|
-some header files in common, and special provision has been made to
|
|
|
+the source code originate in the Linux source tree, we have some
|
|
|
+header files in common, and special provision has been made to
|
|
|
support booting of Linux images.
|
|
|
|
|
|
Some attention has been paid to make this software easily
|
|
@@ -45,23 +46,20 @@ Status:
|
|
|
=======
|
|
|
|
|
|
In general, all boards for which a configuration option exists in the
|
|
|
-Makefile have been tested to some extent and can be considered
|
|
|
+Makefile have been tested to some extent and can be considered
|
|
|
"working". In fact, many of them are used in production systems.
|
|
|
|
|
|
-In case of problems see the CHANGELOG and CREDITS files to find out
|
|
|
+In case of problems see the CHANGELOG and CREDITS files to find out
|
|
|
who contributed the specific port.
|
|
|
|
|
|
-Exception from this rule: the port to the Sandpoint 8240 has not been
|
|
|
-completed yet.
|
|
|
-
|
|
|
|
|
|
Where to get help:
|
|
|
==================
|
|
|
|
|
|
-In case you have questions about, problems with or contributions for
|
|
|
-U-Boot you should send a message to the U-Boot mailing list at
|
|
|
-<u-boot-users@lists.sourceforge.net>. There is also an archive of
|
|
|
-previous traffic on the mailing list - please search the archive
|
|
|
+In case you have questions about, problems with or contributions for
|
|
|
+U-Boot you should send a message to the U-Boot mailing list at
|
|
|
+<u-boot-users@lists.sourceforge.net>. There is also an archive of
|
|
|
+previous traffic on the mailing list - please search the archive
|
|
|
before asking FAQ's. Please see
|
|
|
http://lists.sourceforge.net/lists/listinfo/u-boot-users/
|
|
|
|
|
@@ -70,6 +68,7 @@ Where we come from:
|
|
|
===================
|
|
|
|
|
|
- start from 8xxrom sources
|
|
|
+- create PPCBoot project (http://sourceforge.net/projects/ppcboot)
|
|
|
- clean up code
|
|
|
- make it easier to add custom boards
|
|
|
- make it possible to add other [PowerPC] CPUs
|
|
@@ -78,7 +77,31 @@ Where we come from:
|
|
|
* S-Record download
|
|
|
* network boot
|
|
|
* PCMCIA / CompactFLash / ATA disk / SCSI ... boot
|
|
|
+- create ARMBoot project (http://sourceforge.net/projects/armboot)
|
|
|
- add other CPU families (starting with ARM)
|
|
|
+- create U-Boot project (http://sourceforge.net/projects/u-boot)
|
|
|
+
|
|
|
+
|
|
|
+Names and Spelling:
|
|
|
+===================
|
|
|
+
|
|
|
+The "official" name of this project is "Das U-Boot". The spelling
|
|
|
+"U-Boot" shall be used in all written text (documentation, comments
|
|
|
+in source files etc.). Example:
|
|
|
+
|
|
|
+ This is the README file for the U-Boot project.
|
|
|
+
|
|
|
+File names etc. shall be based on the string "u-boot". Examples:
|
|
|
+
|
|
|
+ include/asm-ppc/u-boot.h
|
|
|
+
|
|
|
+ #include <asm/u-boot.h>
|
|
|
+
|
|
|
+Variable names, preprocessor constants etc. shall be either based on
|
|
|
+the string "u_boot" or on "U_BOOT". Example:
|
|
|
+
|
|
|
+ U_BOOT_VERSION u_boot_logo
|
|
|
+ IH_OS_U_BOOT u_boot_hush_start
|
|
|
|
|
|
|
|
|
Directory Hierarchy:
|
|
@@ -1675,7 +1698,7 @@ Note: for some board special configuration names may exist; check if
|
|
|
|
|
|
|
|
|
|
|
|
-Finally, type "make all", and you should get some working U-Boot
|
|
|
+Finally, type "make all", and you should get some working U-Boot
|
|
|
images ready for downlod to / installation on your system:
|
|
|
|
|
|
- "u-boot.bin" is a raw binary image
|
|
@@ -2013,28 +2036,55 @@ device (initial ramdisk, NFS) for your target system.
|
|
|
Building a Linux Image:
|
|
|
-----------------------
|
|
|
|
|
|
-No specific requirements for U-Boot. There is no need to add a
|
|
|
-"ramdisk.image.gz" file when building the kernel, even when you
|
|
|
-intend to run it with initial ramdisk.
|
|
|
+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 zImage
|
|
|
+ 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:
|
|
|
|
|
|
-However, we don't use the 'zImage' (= 'arch/ppc/mbxboot/zvmlinux') we
|
|
|
-build this way. The 'zImage' includes the old boot loader code which
|
|
|
-we don't ned any more. Instead, we use the raw (compressed) Linux
|
|
|
-kernel image in 'arch/ppc/coffboot/vmlinux.gz'.
|
|
|
+* build a standard "vmlinux" kernel image (in ELF binary format):
|
|
|
|
|
|
-There is a special tool (in 'tools/mkimage') to encapsulate this
|
|
|
-image with header information, CRC32 checksum etc. for use with
|
|
|
-U-Boot:
|
|
|
+* convert the kernel into a raw binary image:
|
|
|
|
|
|
-In the first form (with "-l" option) mkimage lists the information
|
|
|
-contained in the header of an existing U-Boot image; this includes
|
|
|
+ ${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
|
|
|
+
|
|
|
+
|
|
|
+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:
|
|
|
|
|
|
tools/mkimage -l image
|
|
@@ -2058,47 +2108,47 @@ 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 2.4.x kernels have the entry point at 0x00000000.
|
|
|
+- 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 '2.2.13 for initrd on TQM850L' \
|
|
|
- > -A ppc -O linux -T kernel -C gzip -a 00000000 -e 0000000C \
|
|
|
- > -d /opt/mpc8xx/src/linux-2.2.13/arch/ppc/coffboot/vmlinux.gz \
|
|
|
- > examples/image-2.2.13-initrd
|
|
|
- Image Name: 2.2.13 for initrd on TQM850L
|
|
|
+ -> 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: 0x0000000c
|
|
|
+ Entry Point: 0x00000000
|
|
|
|
|
|
To verify the contents of the image (or check for corruption):
|
|
|
|
|
|
- -> tools/mkimage -l examples/image-2.2.13-initrd
|
|
|
- Image Name: 2.2.13 for initrd on TQM850L
|
|
|
+ -> 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: 0x0000000c
|
|
|
+ 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/mpc8xx/src/linux-2.2.13/arch/ppc/coffboot/vmlinux.gz
|
|
|
- -> tools/mkimage -n '2.2.13 for initrd on TQM850L' \
|
|
|
- > -A ppc -O linux -T kernel -C none -a 00000000 -e 0000000C \
|
|
|
- > -d /opt/mpc8xx/src/linux-2.2.13/arch/ppc/coffboot/vmlinux \
|
|
|
- > examples/image-2.2.13-initrd-uncompressed
|
|
|
- Image Name: 2.2.13 for initrd on TQM850L
|
|
|
+ -> 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: 0x0000000c
|
|
|
+ Entry Point: 0x00000000
|
|
|
|
|
|
|
|
|
Similar you can build U-Boot images from a 'ramdisk.image.gz' file
|