README 106 KB

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  1. #
  2. # (C) Copyright 2000 - 2002
  3. # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  4. #
  5. # See file CREDITS for list of people who contributed to this
  6. # project.
  7. #
  8. # This program is free software; you can redistribute it and/or
  9. # modify it under the terms of the GNU General Public License as
  10. # published by the Free Software Foundation; either version 2 of
  11. # the License, or (at your option) any later version.
  12. #
  13. # This program is distributed in the hope that it will be useful,
  14. # but WITHOUT ANY WARRANTY; without even the implied warranty of
  15. # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16. # GNU General Public License for more details.
  17. #
  18. # You should have received a copy of the GNU General Public License
  19. # along with this program; if not, write to the Free Software
  20. # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21. # MA 02111-1307 USA
  22. #
  23. Summary:
  24. ========
  25. This directory contains the source code for U-Boot, a boot loader for
  26. Embedded boards based on PowerPC and ARM processors, which can be
  27. installed in a boot ROM and used to initialize and test the hardware
  28. or to download and run application code.
  29. The development of U-Boot is closely related to Linux: some parts of
  30. the source code originate in the Linux source tree, we have some
  31. header files in common, and special provision has been made to
  32. support booting of Linux images.
  33. Some attention has been paid to make this software easily
  34. configurable and extendable. For instance, all monitor commands are
  35. implemented with the same call interface, so that it's very easy to
  36. add new commands. Also, instead of permanently adding rarely used
  37. code (for instance hardware test utilities) to the monitor, you can
  38. load and run it dynamically.
  39. Status:
  40. =======
  41. In general, all boards for which a configuration option exists in the
  42. Makefile have been tested to some extent and can be considered
  43. "working". In fact, many of them are used in production systems.
  44. In case of problems see the CHANGELOG and CREDITS files to find out
  45. who contributed the specific port.
  46. Where to get help:
  47. ==================
  48. In case you have questions about, problems with or contributions for
  49. U-Boot you should send a message to the U-Boot mailing list at
  50. <u-boot-users@lists.sourceforge.net>. There is also an archive of
  51. previous traffic on the mailing list - please search the archive
  52. before asking FAQ's. Please see
  53. http://lists.sourceforge.net/lists/listinfo/u-boot-users/
  54. Where we come from:
  55. ===================
  56. - start from 8xxrom sources
  57. - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
  58. - clean up code
  59. - make it easier to add custom boards
  60. - make it possible to add other [PowerPC] CPUs
  61. - extend functions, especially:
  62. * Provide extended interface to Linux boot loader
  63. * S-Record download
  64. * network boot
  65. * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
  66. - create ARMBoot project (http://sourceforge.net/projects/armboot)
  67. - add other CPU families (starting with ARM)
  68. - create U-Boot project (http://sourceforge.net/projects/u-boot)
  69. Names and Spelling:
  70. ===================
  71. The "official" name of this project is "Das U-Boot". The spelling
  72. "U-Boot" shall be used in all written text (documentation, comments
  73. in source files etc.). Example:
  74. This is the README file for the U-Boot project.
  75. File names etc. shall be based on the string "u-boot". Examples:
  76. include/asm-ppc/u-boot.h
  77. #include <asm/u-boot.h>
  78. Variable names, preprocessor constants etc. shall be either based on
  79. the string "u_boot" or on "U_BOOT". Example:
  80. U_BOOT_VERSION u_boot_logo
  81. IH_OS_U_BOOT u_boot_hush_start
  82. Versioning:
  83. ===========
  84. U-Boot uses a 3 level version number containing a version, a
  85. sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
  86. sub-version "34", and patchlevel "4".
  87. The patchlevel is used to indicate certain stages of development
  88. between released versions, i. e. officially released versions of
  89. U-Boot will always have a patchlevel of "0".
  90. Directory Hierarchy:
  91. ====================
  92. - board Board dependent files
  93. - common Misc architecture independent functions
  94. - cpu CPU specific files
  95. - disk Code for disk drive partition handling
  96. - doc Documentation (don't expect too much)
  97. - drivers Commonly used device drivers
  98. - dtt Digital Thermometer and Thermostat drivers
  99. - examples Example code for standalone applications, etc.
  100. - include Header Files
  101. - disk Harddisk interface code
  102. - net Networking code
  103. - ppc Files generic to PowerPC architecture
  104. - post Power On Self Test
  105. - post/arch Symlink to architecture specific Power On Self Test
  106. - post/arch-ppc PowerPC architecture specific Power On Self Test
  107. - post/cpu/mpc8260 MPC8260 CPU specific Power On Self Test
  108. - post/cpu/mpc8xx MPC8xx CPU specific Power On Self Test
  109. - rtc Real Time Clock drivers
  110. - tools Tools to build S-Record or U-Boot images, etc.
  111. - cpu/74xx_7xx Files specific to Motorola MPC74xx and 7xx CPUs
  112. - cpu/arm925t Files specific to ARM 925 CPUs
  113. - cpu/arm926ejs Files specific to ARM 926 CPUs
  114. - cpu/mpc5xx Files specific to Motorola MPC5xx CPUs
  115. - cpu/mpc8xx Files specific to Motorola MPC8xx CPUs
  116. - cpu/mpc824x Files specific to Motorola MPC824x CPUs
  117. - cpu/mpc8260 Files specific to Motorola MPC8260 CPU
  118. - cpu/ppc4xx Files specific to IBM 4xx CPUs
  119. - board/LEOX/ Files specific to boards manufactured by The LEOX team
  120. - board/LEOX/elpt860 Files specific to ELPT860 boards
  121. - board/RPXClassic
  122. Files specific to RPXClassic boards
  123. - board/RPXlite Files specific to RPXlite boards
  124. - board/at91rm9200dk Files specific to AT91RM9200DK boards
  125. - board/c2mon Files specific to c2mon boards
  126. - board/cmi Files specific to cmi boards
  127. - board/cogent Files specific to Cogent boards
  128. (need further configuration)
  129. Files specific to CPCIISER4 boards
  130. - board/cpu86 Files specific to CPU86 boards
  131. - board/cray/ Files specific to boards manufactured by Cray
  132. - board/cray/L1 Files specific to L1 boards
  133. - board/cu824 Files specific to CU824 boards
  134. - board/ebony Files specific to IBM Ebony board
  135. - board/eric Files specific to ERIC boards
  136. - board/esd/ Files specific to boards manufactured by ESD
  137. - board/esd/adciop Files specific to ADCIOP boards
  138. - board/esd/ar405 Files specific to AR405 boards
  139. - board/esd/canbt Files specific to CANBT boards
  140. - board/esd/cpci405 Files specific to CPCI405 boards
  141. - board/esd/cpciiser4 Files specific to CPCIISER4 boards
  142. - board/esd/common Common files for ESD boards
  143. - board/esd/dasa_sim Files specific to DASA_SIM boards
  144. - board/esd/du405 Files specific to DU405 boards
  145. - board/esd/ocrtc Files specific to OCRTC boards
  146. - board/esd/pci405 Files specific to PCI405 boards
  147. - board/esteem192e
  148. Files specific to ESTEEM192E boards
  149. - board/etx094 Files specific to ETX_094 boards
  150. - board/evb64260
  151. Files specific to EVB64260 boards
  152. - board/fads Files specific to FADS boards
  153. - board/flagadm Files specific to FLAGADM boards
  154. - board/gen860t Files specific to GEN860T and GEN860T_SC boards
  155. - board/genietv Files specific to GENIETV boards
  156. - board/gth Files specific to GTH boards
  157. - board/hermes Files specific to HERMES boards
  158. - board/hymod Files specific to HYMOD boards
  159. - board/icu862 Files specific to ICU862 boards
  160. - board/ip860 Files specific to IP860 boards
  161. - board/iphase4539
  162. Files specific to Interphase4539 boards
  163. - board/ivm Files specific to IVMS8/IVML24 boards
  164. - board/lantec Files specific to LANTEC boards
  165. - board/lwmon Files specific to LWMON boards
  166. - board/mbx8xx Files specific to MBX boards
  167. - board/mpc8260ads
  168. Files specific to MPC8260ADS and PQ2FADS-ZU boards
  169. - board/mpl/ Files specific to boards manufactured by MPL
  170. - board/mpl/common Common files for MPL boards
  171. - board/mpl/pip405 Files specific to PIP405 boards
  172. - board/mpl/mip405 Files specific to MIP405 boards
  173. - board/mpl/vcma9 Files specific to VCMA9 boards
  174. - board/musenki Files specific to MUSEKNI boards
  175. - board/mvs1 Files specific to MVS1 boards
  176. - board/nx823 Files specific to NX823 boards
  177. - board/oxc Files specific to OXC boards
  178. - board/omap1510inn
  179. Files specific to OMAP 1510 Innovator boards
  180. - board/omap1610inn
  181. Files specific to OMAP 1610 Innovator boards
  182. - board/pcippc2 Files specific to PCIPPC2/PCIPPC6 boards
  183. - board/pm826 Files specific to PM826 boards
  184. - board/ppmc8260
  185. Files specific to PPMC8260 boards
  186. - board/rpxsuper
  187. Files specific to RPXsuper boards
  188. - board/rsdproto
  189. Files specific to RSDproto boards
  190. - board/sandpoint
  191. Files specific to Sandpoint boards
  192. - board/sbc8260 Files specific to SBC8260 boards
  193. - board/sacsng Files specific to SACSng boards
  194. - board/siemens Files specific to boards manufactured by Siemens AG
  195. - board/siemens/CCM Files specific to CCM boards
  196. - board/siemens/IAD210 Files specific to IAD210 boards
  197. - board/siemens/SCM Files specific to SCM boards
  198. - board/siemens/pcu_e Files specific to PCU_E boards
  199. - board/sixnet Files specific to SIXNET boards
  200. - board/spd8xx Files specific to SPD8xxTS boards
  201. - board/tqm8260 Files specific to TQM8260 boards
  202. - board/tqm8xx Files specific to TQM8xxL boards
  203. - board/w7o Files specific to W7O boards
  204. - board/walnut405
  205. Files specific to Walnut405 boards
  206. - board/westel/ Files specific to boards manufactured by Westel Wireless
  207. - board/westel/amx860 Files specific to AMX860 boards
  208. - board/utx8245 Files specific to UTX8245 boards
  209. Software Configuration:
  210. =======================
  211. Configuration is usually done using C preprocessor defines; the
  212. rationale behind that is to avoid dead code whenever possible.
  213. There are two classes of configuration variables:
  214. * Configuration _OPTIONS_:
  215. These are selectable by the user and have names beginning with
  216. "CONFIG_".
  217. * Configuration _SETTINGS_:
  218. These depend on the hardware etc. and should not be meddled with if
  219. you don't know what you're doing; they have names beginning with
  220. "CFG_".
  221. Later we will add a configuration tool - probably similar to or even
  222. identical to what's used for the Linux kernel. Right now, we have to
  223. do the configuration by hand, which means creating some symbolic
  224. links and editing some configuration files. We use the TQM8xxL boards
  225. as an example here.
  226. Selection of Processor Architecture and Board Type:
  227. ---------------------------------------------------
  228. For all supported boards there are ready-to-use default
  229. configurations available; just type "make <board_name>_config".
  230. Example: For a TQM823L module type:
  231. cd u-boot
  232. make TQM823L_config
  233. For the Cogent platform, you need to specify the cpu type as well;
  234. e.g. "make cogent_mpc8xx_config". And also configure the cogent
  235. directory according to the instructions in cogent/README.
  236. Configuration Options:
  237. ----------------------
  238. Configuration depends on the combination of board and CPU type; all
  239. such information is kept in a configuration file
  240. "include/configs/<board_name>.h".
  241. Example: For a TQM823L module, all configuration settings are in
  242. "include/configs/TQM823L.h".
  243. Many of the options are named exactly as the corresponding Linux
  244. kernel configuration options. The intention is to make it easier to
  245. build a config tool - later.
  246. The following options need to be configured:
  247. - CPU Type: Define exactly one of
  248. PowerPC based CPUs:
  249. -------------------
  250. CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860
  251. or CONFIG_MPC5xx
  252. or CONFIG_MPC824X, CONFIG_MPC8260
  253. or CONFIG_IOP480
  254. or CONFIG_405GP
  255. or CONFIG_405EP
  256. or CONFIG_440
  257. or CONFIG_MPC74xx
  258. or CONFIG_750FX
  259. ARM based CPUs:
  260. ---------------
  261. CONFIG_SA1110
  262. CONFIG_ARM7
  263. CONFIG_PXA250
  264. - Board Type: Define exactly one of
  265. PowerPC based boards:
  266. ---------------------
  267. CONFIG_ADCIOP, CONFIG_ICU862 CONFIG_RPXsuper,
  268. CONFIG_ADS860, CONFIG_IP860, CONFIG_SM850,
  269. CONFIG_AMX860, CONFIG_IPHASE4539, CONFIG_SPD823TS,
  270. CONFIG_AR405, CONFIG_IVML24, CONFIG_SXNI855T,
  271. CONFIG_BAB7xx, CONFIG_IVML24_128, CONFIG_Sandpoint8240,
  272. CONFIG_CANBT, CONFIG_IVML24_256, CONFIG_Sandpoint8245,
  273. CONFIG_CCM, CONFIG_IVMS8, CONFIG_TQM823L,
  274. CONFIG_CPCI405, CONFIG_IVMS8_128, CONFIG_TQM850L,
  275. CONFIG_CPCI4052, CONFIG_IVMS8_256, CONFIG_TQM855L,
  276. CONFIG_CPCIISER4, CONFIG_LANTEC, CONFIG_TQM860L,
  277. CONFIG_CPU86, CONFIG_MBX, CONFIG_TQM8260,
  278. CONFIG_CRAYL1, CONFIG_MBX860T, CONFIG_TTTech,
  279. CONFIG_CU824, CONFIG_MHPC, CONFIG_UTX8245,
  280. CONFIG_DASA_SIM, CONFIG_MIP405, CONFIG_W7OLMC,
  281. CONFIG_DU405, CONFIG_MOUSSE, CONFIG_W7OLMG,
  282. CONFIG_ELPPC, CONFIG_MPC8260ADS, CONFIG_WALNUT405,
  283. CONFIG_ERIC, CONFIG_MUSENKI, CONFIG_ZUMA,
  284. CONFIG_ESTEEM192E, CONFIG_MVS1, CONFIG_c2mon,
  285. CONFIG_ETX094, CONFIG_NX823, CONFIG_cogent_mpc8260,
  286. CONFIG_EVB64260, CONFIG_OCRTC, CONFIG_cogent_mpc8xx,
  287. CONFIG_FADS823, CONFIG_ORSG, CONFIG_ep8260,
  288. CONFIG_FADS850SAR, CONFIG_OXC, CONFIG_gw8260,
  289. CONFIG_FADS860T, CONFIG_PCI405, CONFIG_hermes,
  290. CONFIG_FLAGADM, CONFIG_PCIPPC2, CONFIG_hymod,
  291. CONFIG_FPS850L, CONFIG_PCIPPC6, CONFIG_lwmon,
  292. CONFIG_GEN860T, CONFIG_PIP405, CONFIG_pcu_e,
  293. CONFIG_GENIETV, CONFIG_PM826, CONFIG_ppmc8260,
  294. CONFIG_GTH, CONFIG_RPXClassic, CONFIG_rsdproto,
  295. CONFIG_IAD210, CONFIG_RPXlite, CONFIG_sbc8260,
  296. CONFIG_EBONY, CONFIG_sacsng, CONFIG_FPS860L,
  297. CONFIG_V37, CONFIG_ELPT860, CONFIG_CMI,
  298. CONFIG_NETVIA, CONFIG_RBC823
  299. ARM based boards:
  300. -----------------
  301. CONFIG_HHP_CRADLE, CONFIG_DNP1110, CONFIG_EP7312,
  302. CONFIG_IMPA7, CONFIG_LART, CONFIG_LUBBOCK,
  303. CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610
  304. CONFIG_SHANNON, CONFIG_SMDK2400, CONFIG_SMDK2410,
  305. CONFIG_TRAB, CONFIG_VCMA9, CONFIG_AT91RM9200DK
  306. - CPU Module Type: (if CONFIG_COGENT is defined)
  307. Define exactly one of
  308. CONFIG_CMA286_60_OLD
  309. --- FIXME --- not tested yet:
  310. CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
  311. CONFIG_CMA287_23, CONFIG_CMA287_50
  312. - Motherboard Type: (if CONFIG_COGENT is defined)
  313. Define exactly one of
  314. CONFIG_CMA101, CONFIG_CMA102
  315. - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
  316. Define one or more of
  317. CONFIG_CMA302
  318. - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
  319. Define one or more of
  320. CONFIG_LCD_HEARTBEAT - update a character position on
  321. the lcd display every second with
  322. a "rotator" |\-/|\-/
  323. - Board flavour: (if CONFIG_MPC8260ADS is defined)
  324. CONFIG_ADSTYPE
  325. Possible values are:
  326. CFG_8260ADS - original MPC8260ADS
  327. CFG_8266ADS - MPC8266ADS (untested)
  328. CFG_PQ2FADS - PQ2FADS-ZU
  329. - MPC824X Family Member (if CONFIG_MPC824X is defined)
  330. Define exactly one of
  331. CONFIG_MPC8240, CONFIG_MPC8245
  332. - 8xx CPU Options: (if using an 8xx cpu)
  333. Define one or more of
  334. CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() can not work e.g.
  335. no 32KHz reference PIT/RTC clock
  336. - Clock Interface:
  337. CONFIG_CLOCKS_IN_MHZ
  338. U-Boot stores all clock information in Hz
  339. internally. For binary compatibility with older Linux
  340. kernels (which expect the clocks passed in the
  341. bd_info data to be in MHz) the environment variable
  342. "clocks_in_mhz" can be defined so that U-Boot
  343. converts clock data to MHZ before passing it to the
  344. Linux kernel.
  345. When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
  346. "clocks_in_mhz=1" is automatically included in the
  347. default environment.
  348. - Console Interface:
  349. Depending on board, define exactly one serial port
  350. (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
  351. CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
  352. console by defining CONFIG_8xx_CONS_NONE
  353. Note: if CONFIG_8xx_CONS_NONE is defined, the serial
  354. port routines must be defined elsewhere
  355. (i.e. serial_init(), serial_getc(), ...)
  356. CONFIG_CFB_CONSOLE
  357. Enables console device for a color framebuffer. Needs following
  358. defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
  359. VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
  360. (default big endian)
  361. VIDEO_HW_RECTFILL graphic chip supports
  362. rectangle fill
  363. (cf. smiLynxEM)
  364. VIDEO_HW_BITBLT graphic chip supports
  365. bit-blit (cf. smiLynxEM)
  366. VIDEO_VISIBLE_COLS visible pixel columns
  367. (cols=pitch)
  368. VIDEO_VISIBLE_ROWS visible pixel rows
  369. VIDEO_PIXEL_SIZE bytes per pixel
  370. VIDEO_DATA_FORMAT graphic data format
  371. (0-5, cf. cfb_console.c)
  372. VIDEO_FB_ADRS framebuffer address
  373. VIDEO_KBD_INIT_FCT keyboard int fct
  374. (i.e. i8042_kbd_init())
  375. VIDEO_TSTC_FCT test char fct
  376. (i.e. i8042_tstc)
  377. VIDEO_GETC_FCT get char fct
  378. (i.e. i8042_getc)
  379. CONFIG_CONSOLE_CURSOR cursor drawing on/off
  380. (requires blink timer
  381. cf. i8042.c)
  382. CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
  383. CONFIG_CONSOLE_TIME display time/date info in
  384. upper right corner
  385. (requires CFG_CMD_DATE)
  386. CONFIG_VIDEO_LOGO display Linux logo in
  387. upper left corner
  388. CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
  389. linux_logo.h for logo.
  390. Requires CONFIG_VIDEO_LOGO
  391. CONFIG_CONSOLE_EXTRA_INFO
  392. addional board info beside
  393. the logo
  394. When CONFIG_CFB_CONSOLE is defined, video console is
  395. default i/o. Serial console can be forced with
  396. environment 'console=serial'.
  397. - Console Baudrate:
  398. CONFIG_BAUDRATE - in bps
  399. Select one of the baudrates listed in
  400. CFG_BAUDRATE_TABLE, see below.
  401. - Interrupt driven serial port input:
  402. CONFIG_SERIAL_SOFTWARE_FIFO
  403. PPC405GP only.
  404. Use an interrupt handler for receiving data on the
  405. serial port. It also enables using hardware handshake
  406. (RTS/CTS) and UART's built-in FIFO. Set the number of
  407. bytes the interrupt driven input buffer should have.
  408. Set to 0 to disable this feature (this is the default).
  409. This will also disable hardware handshake.
  410. - Console UART Number:
  411. CONFIG_UART1_CONSOLE
  412. IBM PPC4xx only.
  413. If defined internal UART1 (and not UART0) is used
  414. as default U-Boot console.
  415. - Boot Delay: CONFIG_BOOTDELAY - in seconds
  416. Delay before automatically booting the default image;
  417. set to -1 to disable autoboot.
  418. See doc/README.autoboot for these options that
  419. work with CONFIG_BOOTDELAY. None are required.
  420. CONFIG_BOOT_RETRY_TIME
  421. CONFIG_BOOT_RETRY_MIN
  422. CONFIG_AUTOBOOT_KEYED
  423. CONFIG_AUTOBOOT_PROMPT
  424. CONFIG_AUTOBOOT_DELAY_STR
  425. CONFIG_AUTOBOOT_STOP_STR
  426. CONFIG_AUTOBOOT_DELAY_STR2
  427. CONFIG_AUTOBOOT_STOP_STR2
  428. CONFIG_ZERO_BOOTDELAY_CHECK
  429. CONFIG_RESET_TO_RETRY
  430. - Autoboot Command:
  431. CONFIG_BOOTCOMMAND
  432. Only needed when CONFIG_BOOTDELAY is enabled;
  433. define a command string that is automatically executed
  434. when no character is read on the console interface
  435. within "Boot Delay" after reset.
  436. CONFIG_BOOTARGS
  437. This can be used to pass arguments to the bootm
  438. command. The value of CONFIG_BOOTARGS goes into the
  439. environment value "bootargs".
  440. CONFIG_RAMBOOT and CONFIG_NFSBOOT
  441. The value of these goes into the environment as
  442. "ramboot" and "nfsboot" respectively, and can be used
  443. as a convenience, when switching between booting from
  444. ram and nfs.
  445. - Pre-Boot Commands:
  446. CONFIG_PREBOOT
  447. When this option is #defined, the existence of the
  448. environment variable "preboot" will be checked
  449. immediately before starting the CONFIG_BOOTDELAY
  450. countdown and/or running the auto-boot command resp.
  451. entering interactive mode.
  452. This feature is especially useful when "preboot" is
  453. automatically generated or modified. For an example
  454. see the LWMON board specific code: here "preboot" is
  455. modified when the user holds down a certain
  456. combination of keys on the (special) keyboard when
  457. booting the systems
  458. - Serial Download Echo Mode:
  459. CONFIG_LOADS_ECHO
  460. If defined to 1, all characters received during a
  461. serial download (using the "loads" command) are
  462. echoed back. This might be needed by some terminal
  463. emulations (like "cu"), but may as well just take
  464. time on others. This setting #define's the initial
  465. value of the "loads_echo" environment variable.
  466. - Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
  467. CONFIG_KGDB_BAUDRATE
  468. Select one of the baudrates listed in
  469. CFG_BAUDRATE_TABLE, see below.
  470. - Monitor Functions:
  471. CONFIG_COMMANDS
  472. Most monitor functions can be selected (or
  473. de-selected) by adjusting the definition of
  474. CONFIG_COMMANDS; to select individual functions,
  475. #define CONFIG_COMMANDS by "OR"ing any of the
  476. following values:
  477. #define enables commands:
  478. -------------------------
  479. CFG_CMD_ASKENV * ask for env variable
  480. CFG_CMD_AUTOSCRIPT Autoscript Support
  481. CFG_CMD_BDI bdinfo
  482. CFG_CMD_BEDBUG Include BedBug Debugger
  483. CFG_CMD_BMP * BMP support
  484. CFG_CMD_BOOTD bootd
  485. CFG_CMD_CACHE icache, dcache
  486. CFG_CMD_CONSOLE coninfo
  487. CFG_CMD_DATE * support for RTC, date/time...
  488. CFG_CMD_DHCP DHCP support
  489. CFG_CMD_DIAG * Diagnostics
  490. CFG_CMD_DOC * Disk-On-Chip Support
  491. CFG_CMD_DTT Digital Therm and Thermostat
  492. CFG_CMD_ECHO * echo arguments
  493. CFG_CMD_EEPROM * EEPROM read/write support
  494. CFG_CMD_ELF bootelf, bootvx
  495. CFG_CMD_ENV saveenv
  496. CFG_CMD_FDC * Floppy Disk Support
  497. CFG_CMD_FAT FAT partition support
  498. CFG_CMD_FDOS * Dos diskette Support
  499. CFG_CMD_FLASH flinfo, erase, protect
  500. CFG_CMD_FPGA FPGA device initialization support
  501. CFG_CMD_HWFLOW * RTS/CTS hw flow control
  502. CFG_CMD_I2C * I2C serial bus support
  503. CFG_CMD_IDE * IDE harddisk support
  504. CFG_CMD_IMI iminfo
  505. CFG_CMD_IMLS List all found images
  506. CFG_CMD_IMMAP * IMMR dump support
  507. CFG_CMD_IRQ * irqinfo
  508. CFG_CMD_JFFS2 * JFFS2 Support
  509. CFG_CMD_KGDB * kgdb
  510. CFG_CMD_LOADB loadb
  511. CFG_CMD_LOADS loads
  512. CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
  513. loop, mtest
  514. CFG_CMD_MISC Misc functions like sleep etc
  515. CFG_CMD_MMC MMC memory mapped support
  516. CFG_CMD_MII MII utility commands
  517. CFG_CMD_NAND * NAND support
  518. CFG_CMD_NET bootp, tftpboot, rarpboot
  519. CFG_CMD_PCI * pciinfo
  520. CFG_CMD_PCMCIA * PCMCIA support
  521. CFG_CMD_PING * send ICMP ECHO_REQUEST to network host
  522. CFG_CMD_PORTIO Port I/O
  523. CFG_CMD_REGINFO * Register dump
  524. CFG_CMD_RUN run command in env variable
  525. CFG_CMD_SAVES save S record dump
  526. CFG_CMD_SCSI * SCSI Support
  527. CFG_CMD_SDRAM * print SDRAM configuration information
  528. CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
  529. CFG_CMD_SPI * SPI serial bus support
  530. CFG_CMD_USB * USB support
  531. CFG_CMD_VFD * VFD support (TRAB)
  532. CFG_CMD_BSP * Board SPecific functions
  533. -----------------------------------------------
  534. CFG_CMD_ALL all
  535. CFG_CMD_DFL Default configuration; at the moment
  536. this is includes all commands, except
  537. the ones marked with "*" in the list
  538. above.
  539. If you don't define CONFIG_COMMANDS it defaults to
  540. CFG_CMD_DFL in include/cmd_confdefs.h. A board can
  541. override the default settings in the respective
  542. include file.
  543. EXAMPLE: If you want all functions except of network
  544. support you can write:
  545. #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
  546. Note: Don't enable the "icache" and "dcache" commands
  547. (configuration option CFG_CMD_CACHE) unless you know
  548. what you (and your U-Boot users) are doing. Data
  549. cache cannot be enabled on systems like the 8xx or
  550. 8260 (where accesses to the IMMR region must be
  551. uncached), and it cannot be disabled on all other
  552. systems where we (mis-) use the data cache to hold an
  553. initial stack and some data.
  554. XXX - this list needs to get updated!
  555. - Watchdog:
  556. CONFIG_WATCHDOG
  557. If this variable is defined, it enables watchdog
  558. support. There must be support in the platform specific
  559. code for a watchdog. For the 8xx and 8260 CPUs, the
  560. SIU Watchdog feature is enabled in the SYPCR
  561. register.
  562. - U-Boot Version:
  563. CONFIG_VERSION_VARIABLE
  564. If this variable is defined, an environment variable
  565. named "ver" is created by U-Boot showing the U-Boot
  566. version as printed by the "version" command.
  567. This variable is readonly.
  568. - Real-Time Clock:
  569. When CFG_CMD_DATE is selected, the type of the RTC
  570. has to be selected, too. Define exactly one of the
  571. following options:
  572. CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
  573. CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
  574. CONFIG_RTC_MC146818 - use MC146818 RTC
  575. CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
  576. CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
  577. CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
  578. CONFIG_RTC_DS164x - use Dallas DS164x RTC
  579. Note that if the RTC uses I2C, then the I2C interface
  580. must also be configured. See I2C Support, below.
  581. - Timestamp Support:
  582. When CONFIG_TIMESTAMP is selected, the timestamp
  583. (date and time) of an image is printed by image
  584. commands like bootm or iminfo. This option is
  585. automatically enabled when you select CFG_CMD_DATE .
  586. - Partition Support:
  587. CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
  588. and/or CONFIG_ISO_PARTITION
  589. If IDE or SCSI support is enabled (CFG_CMD_IDE or
  590. CFG_CMD_SCSI) you must configure support for at least
  591. one partition type as well.
  592. - IDE Reset method:
  593. CONFIG_IDE_RESET_ROUTINE
  594. Set this to define that instead of a reset Pin, the
  595. routine ide_set_reset(int idereset) will be used.
  596. - ATAPI Support:
  597. CONFIG_ATAPI
  598. Set this to enable ATAPI support.
  599. - SCSI Support:
  600. At the moment only there is only support for the
  601. SYM53C8XX SCSI controller; define
  602. CONFIG_SCSI_SYM53C8XX to enable it.
  603. CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
  604. CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
  605. CFG_SCSI_MAX_LUN] can be adjusted to define the
  606. maximum numbers of LUNs, SCSI ID's and target
  607. devices.
  608. CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
  609. - NETWORK Support (PCI):
  610. CONFIG_E1000
  611. Support for Intel 8254x gigabit chips.
  612. CONFIG_EEPRO100
  613. Support for Intel 82557/82559/82559ER chips.
  614. Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
  615. write routine for first time initialisation.
  616. CONFIG_TULIP
  617. Support for Digital 2114x chips.
  618. Optional CONFIG_TULIP_SELECT_MEDIA for board specific
  619. modem chip initialisation (KS8761/QS6611).
  620. CONFIG_NATSEMI
  621. Support for National dp83815 chips.
  622. CONFIG_NS8382X
  623. Support for National dp8382[01] gigabit chips.
  624. - NETWORK Support (other):
  625. CONFIG_DRIVER_LAN91C96
  626. Support for SMSC's LAN91C96 chips.
  627. CONFIG_LAN91C96_BASE
  628. Define this to hold the physical address
  629. of the LAN91C96's I/O space
  630. CONFIG_LAN91C96_USE_32_BIT
  631. Define this to enable 32 bit addressing
  632. - USB Support:
  633. At the moment only the UHCI host controller is
  634. supported (PIP405, MIP405); define
  635. CONFIG_USB_UHCI to enable it.
  636. define CONFIG_USB_KEYBOARD to enable the USB Keyboard
  637. end define CONFIG_USB_STORAGE to enable the USB
  638. storage devices.
  639. Note:
  640. Supported are USB Keyboards and USB Floppy drives
  641. (TEAC FD-05PUB).
  642. - MMC Support:
  643. The MMC controller on the Intel PXA is supported. To
  644. enable this define CONFIG_MMC. The MMC can be
  645. accessed from the boot prompt by mapping the device
  646. to physical memory similar to flash. Command line is
  647. enabled with CFG_CMD_MMC. The MMC driver also works with
  648. the FAT fs. This is enabled with CFG_CMD_FAT.
  649. - Keyboard Support:
  650. CONFIG_ISA_KEYBOARD
  651. Define this to enable standard (PC-Style) keyboard
  652. support
  653. CONFIG_I8042_KBD
  654. Standard PC keyboard driver with US (is default) and
  655. GERMAN key layout (switch via environment 'keymap=de') support.
  656. Export function i8042_kbd_init, i8042_tstc and i8042_getc
  657. for cfb_console. Supports cursor blinking.
  658. - Video support:
  659. CONFIG_VIDEO
  660. Define this to enable video support (for output to
  661. video).
  662. CONFIG_VIDEO_CT69000
  663. Enable Chips & Technologies 69000 Video chip
  664. CONFIG_VIDEO_SMI_LYNXEM
  665. Enable Silicon Motion SMI 712/710/810 Video chip
  666. Videomode are selected via environment 'videomode' with
  667. standard LiLo mode numbers.
  668. Following modes are supported (* is default):
  669. 800x600 1024x768 1280x1024
  670. 256 (8bit) 303* 305 307
  671. 65536 (16bit) 314 317 31a
  672. 16,7 Mill (24bit) 315 318 31b
  673. (i.e. setenv videomode 317; saveenv; reset;)
  674. CONFIG_VIDEO_SED13806
  675. Enable Epson SED13806 driver. This driver supports 8bpp
  676. and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
  677. or CONFIG_VIDEO_SED13806_16BPP
  678. - Keyboard Support:
  679. CONFIG_KEYBOARD
  680. Define this to enable a custom keyboard support.
  681. This simply calls drv_keyboard_init() which must be
  682. defined in your board-specific files.
  683. The only board using this so far is RBC823.
  684. - LCD Support: CONFIG_LCD
  685. Define this to enable LCD support (for output to LCD
  686. display); also select one of the supported displays
  687. by defining one of these:
  688. CONFIG_NEC_NL6648AC33:
  689. NEC NL6648AC33-18. Active, color, single scan.
  690. CONFIG_NEC_NL6648BC20
  691. NEC NL6648BC20-08. 6.5", 640x480.
  692. Active, color, single scan.
  693. CONFIG_SHARP_16x9
  694. Sharp 320x240. Active, color, single scan.
  695. It isn't 16x9, and I am not sure what it is.
  696. CONFIG_SHARP_LQ64D341
  697. Sharp LQ64D341 display, 640x480.
  698. Active, color, single scan.
  699. CONFIG_HLD1045
  700. HLD1045 display, 640x480.
  701. Active, color, single scan.
  702. CONFIG_OPTREX_BW
  703. Optrex CBL50840-2 NF-FW 99 22 M5
  704. or
  705. Hitachi LMG6912RPFC-00T
  706. or
  707. Hitachi SP14Q002
  708. 320x240. Black & white.
  709. Normally display is black on white background; define
  710. CFG_WHITE_ON_BLACK to get it inverted.
  711. - Splash Screen Support: CONFIG_SPLASH_SCREEN
  712. If this option is set, the environment is checked for
  713. a variable "splashimage". If found, the usual display
  714. of logo, copyright and system information on the LCD
  715. is supressed and the BMP image at the address
  716. specified in "splashimage" is loaded instead. The
  717. console is redirected to the "nulldev", too. This
  718. allows for a "silent" boot where a splash screen is
  719. loaded very quickly after power-on.
  720. - Compression support:
  721. CONFIG_BZIP2
  722. If this option is set, support for bzip2 compressed
  723. images is included. If not, only uncompressed and gzip
  724. compressed images are supported.
  725. NOTE: the bzip2 algorithm requires a lot of RAM, so
  726. the malloc area (as defined by CFG_MALLOC_LEN) should
  727. be at least 4MB.
  728. - Ethernet address:
  729. CONFIG_ETHADDR
  730. CONFIG_ETH2ADDR
  731. CONFIG_ETH3ADDR
  732. Define a default value for ethernet address to use
  733. for the respective ethernet interface, in case this
  734. is not determined automatically.
  735. - IP address:
  736. CONFIG_IPADDR
  737. Define a default value for the IP address to use for
  738. the default ethernet interface, in case this is not
  739. determined through e.g. bootp.
  740. - Server IP address:
  741. CONFIG_SERVERIP
  742. Defines a default value for theIP address of a TFTP
  743. server to contact when using the "tftboot" command.
  744. - BOOTP Recovery Mode:
  745. CONFIG_BOOTP_RANDOM_DELAY
  746. If you have many targets in a network that try to
  747. boot using BOOTP, you may want to avoid that all
  748. systems send out BOOTP requests at precisely the same
  749. moment (which would happen for instance at recovery
  750. from a power failure, when all systems will try to
  751. boot, thus flooding the BOOTP server. Defining
  752. CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
  753. inserted before sending out BOOTP requests. The
  754. following delays are insterted then:
  755. 1st BOOTP request: delay 0 ... 1 sec
  756. 2nd BOOTP request: delay 0 ... 2 sec
  757. 3rd BOOTP request: delay 0 ... 4 sec
  758. 4th and following
  759. BOOTP requests: delay 0 ... 8 sec
  760. - DHCP Advanced Options:
  761. CONFIG_BOOTP_MASK
  762. You can fine tune the DHCP functionality by adding
  763. these flags to the CONFIG_BOOTP_MASK define:
  764. CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
  765. serverip from a DHCP server, it is possible that more
  766. than one DNS serverip is offered to the client.
  767. If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
  768. serverip will be stored in the additional environment
  769. variable "dnsip2". The first DNS serverip is always
  770. stored in the variable "dnsip", when CONFIG_BOOTP_DNS
  771. is added to the CONFIG_BOOTP_MASK.
  772. CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
  773. to do a dynamic update of a DNS server. To do this, they
  774. need the hostname of the DHCP requester.
  775. If CONFIG_BOOP_SEND_HOSTNAME is added to the
  776. CONFIG_BOOTP_MASK, the content of the "hostname"
  777. environment variable is passed as option 12 to
  778. the DHCP server.
  779. - Status LED: CONFIG_STATUS_LED
  780. Several configurations allow to display the current
  781. status using a LED. For instance, the LED will blink
  782. fast while running U-Boot code, stop blinking as
  783. soon as a reply to a BOOTP request was received, and
  784. start blinking slow once the Linux kernel is running
  785. (supported by a status LED driver in the Linux
  786. kernel). Defining CONFIG_STATUS_LED enables this
  787. feature in U-Boot.
  788. - CAN Support: CONFIG_CAN_DRIVER
  789. Defining CONFIG_CAN_DRIVER enables CAN driver support
  790. on those systems that support this (optional)
  791. feature, like the TQM8xxL modules.
  792. - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
  793. These enable I2C serial bus commands. Defining either of
  794. (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
  795. include the appropriate I2C driver for the selected cpu.
  796. This will allow you to use i2c commands at the u-boot
  797. command line (as long as you set CFG_CMD_I2C in
  798. CONFIG_COMMANDS) and communicate with i2c based realtime
  799. clock chips. See common/cmd_i2c.c for a description of the
  800. command line interface.
  801. CONFIG_HARD_I2C selects the CPM hardware driver for I2C.
  802. CONFIG_SOFT_I2C configures u-boot to use a software (aka
  803. bit-banging) driver instead of CPM or similar hardware
  804. support for I2C.
  805. There are several other quantities that must also be
  806. defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
  807. In both cases you will need to define CFG_I2C_SPEED
  808. to be the frequency (in Hz) at which you wish your i2c bus
  809. to run and CFG_I2C_SLAVE to be the address of this node (ie
  810. the cpu's i2c node address).
  811. Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
  812. sets the cpu up as a master node and so its address should
  813. therefore be cleared to 0 (See, eg, MPC823e User's Manual
  814. p.16-473). So, set CFG_I2C_SLAVE to 0.
  815. That's all that's required for CONFIG_HARD_I2C.
  816. If you use the software i2c interface (CONFIG_SOFT_I2C)
  817. then the following macros need to be defined (examples are
  818. from include/configs/lwmon.h):
  819. I2C_INIT
  820. (Optional). Any commands necessary to enable the I2C
  821. controller or configure ports.
  822. eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
  823. I2C_PORT
  824. (Only for MPC8260 CPU). The I/O port to use (the code
  825. assumes both bits are on the same port). Valid values
  826. are 0..3 for ports A..D.
  827. I2C_ACTIVE
  828. The code necessary to make the I2C data line active
  829. (driven). If the data line is open collector, this
  830. define can be null.
  831. eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
  832. I2C_TRISTATE
  833. The code necessary to make the I2C data line tri-stated
  834. (inactive). If the data line is open collector, this
  835. define can be null.
  836. eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
  837. I2C_READ
  838. Code that returns TRUE if the I2C data line is high,
  839. FALSE if it is low.
  840. eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
  841. I2C_SDA(bit)
  842. If <bit> is TRUE, sets the I2C data line high. If it
  843. is FALSE, it clears it (low).
  844. eg: #define I2C_SDA(bit) \
  845. if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
  846. else immr->im_cpm.cp_pbdat &= ~PB_SDA
  847. I2C_SCL(bit)
  848. If <bit> is TRUE, sets the I2C clock line high. If it
  849. is FALSE, it clears it (low).
  850. eg: #define I2C_SCL(bit) \
  851. if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
  852. else immr->im_cpm.cp_pbdat &= ~PB_SCL
  853. I2C_DELAY
  854. This delay is invoked four times per clock cycle so this
  855. controls the rate of data transfer. The data rate thus
  856. is 1 / (I2C_DELAY * 4). Often defined to be something
  857. like:
  858. #define I2C_DELAY udelay(2)
  859. CFG_I2C_INIT_BOARD
  860. When a board is reset during an i2c bus transfer
  861. chips might think that the current transfer is still
  862. in progress. On some boards it is possible to access
  863. the i2c SCLK line directly, either by using the
  864. processor pin as a GPIO or by having a second pin
  865. connected to the bus. If this option is defined a
  866. custom i2c_init_board() routine in boards/xxx/board.c
  867. is run early in the boot sequence.
  868. - SPI Support: CONFIG_SPI
  869. Enables SPI driver (so far only tested with
  870. SPI EEPROM, also an instance works with Crystal A/D and
  871. D/As on the SACSng board)
  872. CONFIG_SPI_X
  873. Enables extended (16-bit) SPI EEPROM addressing.
  874. (symmetrical to CONFIG_I2C_X)
  875. CONFIG_SOFT_SPI
  876. Enables a software (bit-bang) SPI driver rather than
  877. using hardware support. This is a general purpose
  878. driver that only requires three general I/O port pins
  879. (two outputs, one input) to function. If this is
  880. defined, the board configuration must define several
  881. SPI configuration items (port pins to use, etc). For
  882. an example, see include/configs/sacsng.h.
  883. - FPGA Support: CONFIG_FPGA_COUNT
  884. Specify the number of FPGA devices to support.
  885. CONFIG_FPGA
  886. Used to specify the types of FPGA devices. For
  887. example,
  888. #define CONFIG_FPGA CFG_XILINX_VIRTEX2
  889. CFG_FPGA_PROG_FEEDBACK
  890. Enable printing of hash marks during FPGA
  891. configuration.
  892. CFG_FPGA_CHECK_BUSY
  893. Enable checks on FPGA configuration interface busy
  894. status by the configuration function. This option
  895. will require a board or device specific function to
  896. be written.
  897. CONFIG_FPGA_DELAY
  898. If defined, a function that provides delays in the
  899. FPGA configuration driver.
  900. CFG_FPGA_CHECK_CTRLC
  901. Allow Control-C to interrupt FPGA configuration
  902. CFG_FPGA_CHECK_ERROR
  903. Check for configuration errors during FPGA bitfile
  904. loading. For example, abort during Virtex II
  905. configuration if the INIT_B line goes low (which
  906. indicated a CRC error).
  907. CFG_FPGA_WAIT_INIT
  908. Maximum time to wait for the INIT_B line to deassert
  909. after PROB_B has been deasserted during a Virtex II
  910. FPGA configuration sequence. The default time is 500 mS.
  911. CFG_FPGA_WAIT_BUSY
  912. Maximum time to wait for BUSY to deassert during
  913. Virtex II FPGA configuration. The default is 5 mS.
  914. CFG_FPGA_WAIT_CONFIG
  915. Time to wait after FPGA configuration. The default is
  916. 200 mS.
  917. - FPGA Support: CONFIG_FPGA_COUNT
  918. Specify the number of FPGA devices to support.
  919. CONFIG_FPGA
  920. Used to specify the types of FPGA devices. For example,
  921. #define CONFIG_FPGA CFG_XILINX_VIRTEX2
  922. CFG_FPGA_PROG_FEEDBACK
  923. Enable printing of hash marks during FPGA configuration.
  924. CFG_FPGA_CHECK_BUSY
  925. Enable checks on FPGA configuration interface busy
  926. status by the configuration function. This option
  927. will require a board or device specific function to
  928. be written.
  929. CONFIG_FPGA_DELAY
  930. If defined, a function that provides delays in the FPGA
  931. configuration driver.
  932. CFG_FPGA_CHECK_CTRLC
  933. Allow Control-C to interrupt FPGA configuration
  934. CFG_FPGA_CHECK_ERROR
  935. Check for configuration errors during FPGA bitfile
  936. loading. For example, abort during Virtex II
  937. configuration if the INIT_B line goes low (which
  938. indicated a CRC error).
  939. CFG_FPGA_WAIT_INIT
  940. Maximum time to wait for the INIT_B line to deassert
  941. after PROB_B has been deasserted during a Virtex II
  942. FPGA configuration sequence. The default time is 500
  943. mS.
  944. CFG_FPGA_WAIT_BUSY
  945. Maximum time to wait for BUSY to deassert during
  946. Virtex II FPGA configuration. The default is 5 mS.
  947. CFG_FPGA_WAIT_CONFIG
  948. Time to wait after FPGA configuration. The default is
  949. 200 mS.
  950. - Configuration Management:
  951. CONFIG_IDENT_STRING
  952. If defined, this string will be added to the U-Boot
  953. version information (U_BOOT_VERSION)
  954. - Vendor Parameter Protection:
  955. U-Boot considers the values of the environment
  956. variables "serial#" (Board Serial Number) and
  957. "ethaddr" (Ethernet Address) to be parameters that
  958. are set once by the board vendor / manufacturer, and
  959. protects these variables from casual modification by
  960. the user. Once set, these variables are read-only,
  961. and write or delete attempts are rejected. You can
  962. change this behviour:
  963. If CONFIG_ENV_OVERWRITE is #defined in your config
  964. file, the write protection for vendor parameters is
  965. completely disabled. Anybody can change or delete
  966. these parameters.
  967. Alternatively, if you #define _both_ CONFIG_ETHADDR
  968. _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
  969. ethernet address is installed in the environment,
  970. which can be changed exactly ONCE by the user. [The
  971. serial# is unaffected by this, i. e. it remains
  972. read-only.]
  973. - Protected RAM:
  974. CONFIG_PRAM
  975. Define this variable to enable the reservation of
  976. "protected RAM", i. e. RAM which is not overwritten
  977. by U-Boot. Define CONFIG_PRAM to hold the number of
  978. kB you want to reserve for pRAM. You can overwrite
  979. this default value by defining an environment
  980. variable "pram" to the number of kB you want to
  981. reserve. Note that the board info structure will
  982. still show the full amount of RAM. If pRAM is
  983. reserved, a new environment variable "mem" will
  984. automatically be defined to hold the amount of
  985. remaining RAM in a form that can be passed as boot
  986. argument to Linux, for instance like that:
  987. setenv bootargs ... mem=\$(mem)
  988. saveenv
  989. This way you can tell Linux not to use this memory,
  990. either, which results in a memory region that will
  991. not be affected by reboots.
  992. *WARNING* If your board configuration uses automatic
  993. detection of the RAM size, you must make sure that
  994. this memory test is non-destructive. So far, the
  995. following board configurations are known to be
  996. "pRAM-clean":
  997. ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
  998. HERMES, IP860, RPXlite, LWMON, LANTEC,
  999. PCU_E, FLAGADM, TQM8260
  1000. - Error Recovery:
  1001. CONFIG_PANIC_HANG
  1002. Define this variable to stop the system in case of a
  1003. fatal error, so that you have to reset it manually.
  1004. This is probably NOT a good idea for an embedded
  1005. system where you want to system to reboot
  1006. automatically as fast as possible, but it may be
  1007. useful during development since you can try to debug
  1008. the conditions that lead to the situation.
  1009. CONFIG_NET_RETRY_COUNT
  1010. This variable defines the number of retries for
  1011. network operations like ARP, RARP, TFTP, or BOOTP
  1012. before giving up the operation. If not defined, a
  1013. default value of 5 is used.
  1014. - Command Interpreter:
  1015. CFG_HUSH_PARSER
  1016. Define this variable to enable the "hush" shell (from
  1017. Busybox) as command line interpreter, thus enabling
  1018. powerful command line syntax like
  1019. if...then...else...fi conditionals or `&&' and '||'
  1020. constructs ("shell scripts").
  1021. If undefined, you get the old, much simpler behaviour
  1022. with a somewhat smaller memory footprint.
  1023. CFG_PROMPT_HUSH_PS2
  1024. This defines the secondary prompt string, which is
  1025. printed when the command interpreter needs more input
  1026. to complete a command. Usually "> ".
  1027. Note:
  1028. In the current implementation, the local variables
  1029. space and global environment variables space are
  1030. separated. Local variables are those you define by
  1031. simply typing `name=value'. To access a local
  1032. variable later on, you have write `$name' or
  1033. `${name}'; to execute the contents of a variable
  1034. directly type `$name' at the command prompt.
  1035. Global environment variables are those you use
  1036. setenv/printenv to work with. To run a command stored
  1037. in such a variable, you need to use the run command,
  1038. and you must not use the '$' sign to access them.
  1039. To store commands and special characters in a
  1040. variable, please use double quotation marks
  1041. surrounding the whole text of the variable, instead
  1042. of the backslashes before semicolons and special
  1043. symbols.
  1044. - Default Environment
  1045. CONFIG_EXTRA_ENV_SETTINGS
  1046. Define this to contain any number of null terminated
  1047. strings (variable = value pairs) that will be part of
  1048. the default environment compiled into the boot image.
  1049. For example, place something like this in your
  1050. board's config file:
  1051. #define CONFIG_EXTRA_ENV_SETTINGS \
  1052. "myvar1=value1\0" \
  1053. "myvar2=value2\0"
  1054. Warning: This method is based on knowledge about the
  1055. internal format how the environment is stored by the
  1056. U-Boot code. This is NOT an official, exported
  1057. interface! Although it is unlikely that this format
  1058. will change soon, there is no guarantee either.
  1059. You better know what you are doing here.
  1060. Note: overly (ab)use of the default environment is
  1061. discouraged. Make sure to check other ways to preset
  1062. the environment like the autoscript function or the
  1063. boot command first.
  1064. - DataFlash Support
  1065. CONFIG_HAS_DATAFLASH
  1066. Defining this option enables DataFlash features and
  1067. allows to read/write in Dataflash via the standard
  1068. commands cp, md...
  1069. - Show boot progress
  1070. CONFIG_SHOW_BOOT_PROGRESS
  1071. Defining this option allows to add some board-
  1072. specific code (calling a user-provided function
  1073. "show_boot_progress(int)") that enables you to show
  1074. the system's boot progress on some display (for
  1075. example, some LED's) on your board. At the moment,
  1076. the following checkpoints are implemented:
  1077. Arg Where When
  1078. 1 common/cmd_bootm.c before attempting to boot an image
  1079. -1 common/cmd_bootm.c Image header has bad magic number
  1080. 2 common/cmd_bootm.c Image header has correct magic number
  1081. -2 common/cmd_bootm.c Image header has bad checksum
  1082. 3 common/cmd_bootm.c Image header has correct checksum
  1083. -3 common/cmd_bootm.c Image data has bad checksum
  1084. 4 common/cmd_bootm.c Image data has correct checksum
  1085. -4 common/cmd_bootm.c Image is for unsupported architecture
  1086. 5 common/cmd_bootm.c Architecture check OK
  1087. -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
  1088. 6 common/cmd_bootm.c Image Type check OK
  1089. -6 common/cmd_bootm.c gunzip uncompression error
  1090. -7 common/cmd_bootm.c Unimplemented compression type
  1091. 7 common/cmd_bootm.c Uncompression OK
  1092. -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
  1093. 8 common/cmd_bootm.c Image Type check OK
  1094. -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
  1095. 9 common/cmd_bootm.c Start initial ramdisk verification
  1096. -10 common/cmd_bootm.c Ramdisk header has bad magic number
  1097. -11 common/cmd_bootm.c Ramdisk header has bad checksum
  1098. 10 common/cmd_bootm.c Ramdisk header is OK
  1099. -12 common/cmd_bootm.c Ramdisk data has bad checksum
  1100. 11 common/cmd_bootm.c Ramdisk data has correct checksum
  1101. 12 common/cmd_bootm.c Ramdisk verification complete, start loading
  1102. -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
  1103. 13 common/cmd_bootm.c Start multifile image verification
  1104. 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
  1105. 15 common/cmd_bootm.c All preparation done, transferring control to OS
  1106. -1 common/cmd_doc.c Bad usage of "doc" command
  1107. -1 common/cmd_doc.c No boot device
  1108. -1 common/cmd_doc.c Unknown Chip ID on boot device
  1109. -1 common/cmd_doc.c Read Error on boot device
  1110. -1 common/cmd_doc.c Image header has bad magic number
  1111. -1 common/cmd_ide.c Bad usage of "ide" command
  1112. -1 common/cmd_ide.c No boot device
  1113. -1 common/cmd_ide.c Unknown boot device
  1114. -1 common/cmd_ide.c Unknown partition table
  1115. -1 common/cmd_ide.c Invalid partition type
  1116. -1 common/cmd_ide.c Read Error on boot device
  1117. -1 common/cmd_ide.c Image header has bad magic number
  1118. -1 common/cmd_nand.c Bad usage of "nand" command
  1119. -1 common/cmd_nand.c No boot device
  1120. -1 common/cmd_nand.c Unknown Chip ID on boot device
  1121. -1 common/cmd_nand.c Read Error on boot device
  1122. -1 common/cmd_nand.c Image header has bad magic number
  1123. -1 common/env_common.c Environment has a bad CRC, using default
  1124. Modem Support:
  1125. --------------
  1126. [so far only for SMDK2400 and TRAB boards]
  1127. - Modem support endable:
  1128. CONFIG_MODEM_SUPPORT
  1129. - RTS/CTS Flow control enable:
  1130. CONFIG_HWFLOW
  1131. - Modem debug support:
  1132. CONFIG_MODEM_SUPPORT_DEBUG
  1133. Enables debugging stuff (char screen[1024], dbg())
  1134. for modem support. Useful only with BDI2000.
  1135. - General:
  1136. In the target system modem support is enabled when a
  1137. specific key (key combination) is pressed during
  1138. power-on. Otherwise U-Boot will boot normally
  1139. (autoboot). The key_pressed() fuction is called from
  1140. board_init(). Currently key_pressed() is a dummy
  1141. function, returning 1 and thus enabling modem
  1142. initialization.
  1143. If there are no modem init strings in the
  1144. environment, U-Boot proceed to autoboot; the
  1145. previous output (banner, info printfs) will be
  1146. supressed, though.
  1147. See also: doc/README.Modem
  1148. Configuration Settings:
  1149. -----------------------
  1150. - CFG_LONGHELP: Defined when you want long help messages included;
  1151. undefine this when you're short of memory.
  1152. - CFG_PROMPT: This is what U-Boot prints on the console to
  1153. prompt for user input.
  1154. - CFG_CBSIZE: Buffer size for input from the Console
  1155. - CFG_PBSIZE: Buffer size for Console output
  1156. - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
  1157. - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
  1158. the application (usually a Linux kernel) when it is
  1159. booted
  1160. - CFG_BAUDRATE_TABLE:
  1161. List of legal baudrate settings for this board.
  1162. - CFG_CONSOLE_INFO_QUIET
  1163. Suppress display of console information at boot.
  1164. - CFG_CONSOLE_IS_IN_ENV
  1165. If the board specific function
  1166. extern int overwrite_console (void);
  1167. returns 1, the stdin, stderr and stdout are switched to the
  1168. serial port, else the settings in the environment are used.
  1169. - CFG_CONSOLE_OVERWRITE_ROUTINE
  1170. Enable the call to overwrite_console().
  1171. - CFG_CONSOLE_ENV_OVERWRITE
  1172. Enable overwrite of previous console environment settings.
  1173. - CFG_MEMTEST_START, CFG_MEMTEST_END:
  1174. Begin and End addresses of the area used by the
  1175. simple memory test.
  1176. - CFG_ALT_MEMTEST:
  1177. Enable an alternate, more extensive memory test.
  1178. - CFG_MEMTEST_SCRATCH:
  1179. Scratch address used by the alternate memory test
  1180. You only need to set this if address zero isn't writeable
  1181. - CFG_TFTP_LOADADDR:
  1182. Default load address for network file downloads
  1183. - CFG_LOADS_BAUD_CHANGE:
  1184. Enable temporary baudrate change while serial download
  1185. - CFG_SDRAM_BASE:
  1186. Physical start address of SDRAM. _Must_ be 0 here.
  1187. - CFG_MBIO_BASE:
  1188. Physical start address of Motherboard I/O (if using a
  1189. Cogent motherboard)
  1190. - CFG_FLASH_BASE:
  1191. Physical start address of Flash memory.
  1192. - CFG_MONITOR_BASE:
  1193. Physical start address of boot monitor code (set by
  1194. make config files to be same as the text base address
  1195. (TEXT_BASE) used when linking) - same as
  1196. CFG_FLASH_BASE when booting from flash.
  1197. - CFG_MONITOR_LEN:
  1198. Size of memory reserved for monitor code, used to
  1199. determine _at_compile_time_ (!) if the environment is
  1200. embedded within the U-Boot image, or in a separate
  1201. flash sector.
  1202. - CFG_MALLOC_LEN:
  1203. Size of DRAM reserved for malloc() use.
  1204. - CFG_BOOTMAPSZ:
  1205. Maximum size of memory mapped by the startup code of
  1206. the Linux kernel; all data that must be processed by
  1207. the Linux kernel (bd_info, boot arguments, eventually
  1208. initrd image) must be put below this limit.
  1209. - CFG_MAX_FLASH_BANKS:
  1210. Max number of Flash memory banks
  1211. - CFG_MAX_FLASH_SECT:
  1212. Max number of sectors on a Flash chip
  1213. - CFG_FLASH_ERASE_TOUT:
  1214. Timeout for Flash erase operations (in ms)
  1215. - CFG_FLASH_WRITE_TOUT:
  1216. Timeout for Flash write operations (in ms)
  1217. - CFG_FLASH_LOCK_TOUT
  1218. Timeout for Flash set sector lock bit operation (in ms)
  1219. - CFG_FLASH_UNLOCK_TOUT
  1220. Timeout for Flash clear lock bits operation (in ms)
  1221. - CFG_FLASH_PROTECTION
  1222. If defined, hardware flash sectors protection is used
  1223. instead of U-Boot software protection.
  1224. - CFG_DIRECT_FLASH_TFTP:
  1225. Enable TFTP transfers directly to flash memory;
  1226. without this option such a download has to be
  1227. performed in two steps: (1) download to RAM, and (2)
  1228. copy from RAM to flash.
  1229. The two-step approach is usually more reliable, since
  1230. you can check if the download worked before you erase
  1231. the flash, but in some situations (when sytem RAM is
  1232. too limited to allow for a tempory copy of the
  1233. downloaded image) this option may be very useful.
  1234. - CFG_FLASH_CFI:
  1235. Define if the flash driver uses extra elements in the
  1236. common flash structure for storing flash geometry
  1237. - CFG_RX_ETH_BUFFER:
  1238. Defines the number of ethernet receive buffers. On some
  1239. ethernet controllers it is recommended to set this value
  1240. to 8 or even higher (EEPRO100 or 405 EMAC), since all
  1241. buffers can be full shortly after enabling the interface
  1242. on high ethernet traffic.
  1243. Defaults to 4 if not defined.
  1244. The following definitions that deal with the placement and management
  1245. of environment data (variable area); in general, we support the
  1246. following configurations:
  1247. - CFG_ENV_IS_IN_FLASH:
  1248. Define this if the environment is in flash memory.
  1249. a) The environment occupies one whole flash sector, which is
  1250. "embedded" in the text segment with the U-Boot code. This
  1251. happens usually with "bottom boot sector" or "top boot
  1252. sector" type flash chips, which have several smaller
  1253. sectors at the start or the end. For instance, such a
  1254. layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
  1255. such a case you would place the environment in one of the
  1256. 4 kB sectors - with U-Boot code before and after it. With
  1257. "top boot sector" type flash chips, you would put the
  1258. environment in one of the last sectors, leaving a gap
  1259. between U-Boot and the environment.
  1260. - CFG_ENV_OFFSET:
  1261. Offset of environment data (variable area) to the
  1262. beginning of flash memory; for instance, with bottom boot
  1263. type flash chips the second sector can be used: the offset
  1264. for this sector is given here.
  1265. CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
  1266. - CFG_ENV_ADDR:
  1267. This is just another way to specify the start address of
  1268. the flash sector containing the environment (instead of
  1269. CFG_ENV_OFFSET).
  1270. - CFG_ENV_SECT_SIZE:
  1271. Size of the sector containing the environment.
  1272. b) Sometimes flash chips have few, equal sized, BIG sectors.
  1273. In such a case you don't want to spend a whole sector for
  1274. the environment.
  1275. - CFG_ENV_SIZE:
  1276. If you use this in combination with CFG_ENV_IS_IN_FLASH
  1277. and CFG_ENV_SECT_SIZE, you can specify to use only a part
  1278. of this flash sector for the environment. This saves
  1279. memory for the RAM copy of the environment.
  1280. It may also save flash memory if you decide to use this
  1281. when your environment is "embedded" within U-Boot code,
  1282. since then the remainder of the flash sector could be used
  1283. for U-Boot code. It should be pointed out that this is
  1284. STRONGLY DISCOURAGED from a robustness point of view:
  1285. updating the environment in flash makes it always
  1286. necessary to erase the WHOLE sector. If something goes
  1287. wrong before the contents has been restored from a copy in
  1288. RAM, your target system will be dead.
  1289. - CFG_ENV_ADDR_REDUND
  1290. CFG_ENV_SIZE_REDUND
  1291. These settings describe a second storage area used to hold
  1292. a redundand copy of the environment data, so that there is
  1293. a valid backup copy in case there is a power failure during
  1294. a "saveenv" operation.
  1295. BE CAREFUL! Any changes to the flash layout, and some changes to the
  1296. source code will make it necessary to adapt <board>/u-boot.lds*
  1297. accordingly!
  1298. - CFG_ENV_IS_IN_NVRAM:
  1299. Define this if you have some non-volatile memory device
  1300. (NVRAM, battery buffered SRAM) which you want to use for the
  1301. environment.
  1302. - CFG_ENV_ADDR:
  1303. - CFG_ENV_SIZE:
  1304. These two #defines are used to determin the memory area you
  1305. want to use for environment. It is assumed that this memory
  1306. can just be read and written to, without any special
  1307. provision.
  1308. BE CAREFUL! The first access to the environment happens quite early
  1309. in U-Boot initalization (when we try to get the setting of for the
  1310. console baudrate). You *MUST* have mappend your NVRAM area then, or
  1311. U-Boot will hang.
  1312. Please note that even with NVRAM we still use a copy of the
  1313. environment in RAM: we could work on NVRAM directly, but we want to
  1314. keep settings there always unmodified except somebody uses "saveenv"
  1315. to save the current settings.
  1316. - CFG_ENV_IS_IN_EEPROM:
  1317. Use this if you have an EEPROM or similar serial access
  1318. device and a driver for it.
  1319. - CFG_ENV_OFFSET:
  1320. - CFG_ENV_SIZE:
  1321. These two #defines specify the offset and size of the
  1322. environment area within the total memory of your EEPROM.
  1323. - CFG_I2C_EEPROM_ADDR:
  1324. If defined, specified the chip address of the EEPROM device.
  1325. The default address is zero.
  1326. - CFG_EEPROM_PAGE_WRITE_BITS:
  1327. If defined, the number of bits used to address bytes in a
  1328. single page in the EEPROM device. A 64 byte page, for example
  1329. would require six bits.
  1330. - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
  1331. If defined, the number of milliseconds to delay between
  1332. page writes. The default is zero milliseconds.
  1333. - CFG_I2C_EEPROM_ADDR_LEN:
  1334. The length in bytes of the EEPROM memory array address. Note
  1335. that this is NOT the chip address length!
  1336. - CFG_EEPROM_SIZE:
  1337. The size in bytes of the EEPROM device.
  1338. - CFG_SPI_INIT_OFFSET
  1339. Defines offset to the initial SPI buffer area in DPRAM. The
  1340. area is used at an early stage (ROM part) if the environment
  1341. is configured to reside in the SPI EEPROM: We need a 520 byte
  1342. scratch DPRAM area. It is used between the two initialization
  1343. calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
  1344. to be a good choice since it makes it far enough from the
  1345. start of the data area as well as from the stack pointer.
  1346. Please note that the environment is read-only as long as the monitor
  1347. has been relocated to RAM and a RAM copy of the environment has been
  1348. created; also, when using EEPROM you will have to use getenv_r()
  1349. until then to read environment variables.
  1350. The environment is protected by a CRC32 checksum. Before the monitor
  1351. is relocated into RAM, as a result of a bad CRC you will be working
  1352. with the compiled-in default environment - *silently*!!! [This is
  1353. necessary, because the first environment variable we need is the
  1354. "baudrate" setting for the console - if we have a bad CRC, we don't
  1355. have any device yet where we could complain.]
  1356. Note: once the monitor has been relocated, then it will complain if
  1357. the default environment is used; a new CRC is computed as soon as you
  1358. use the "saveenv" command to store a valid environment.
  1359. Low Level (hardware related) configuration options:
  1360. ---------------------------------------------------
  1361. - CFG_CACHELINE_SIZE:
  1362. Cache Line Size of the CPU.
  1363. - CFG_DEFAULT_IMMR:
  1364. Default address of the IMMR after system reset.
  1365. Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
  1366. and RPXsuper) to be able to adjust the position of
  1367. the IMMR register after a reset.
  1368. - Floppy Disk Support:
  1369. CFG_FDC_DRIVE_NUMBER
  1370. the default drive number (default value 0)
  1371. CFG_ISA_IO_STRIDE
  1372. defines the spacing between fdc chipset registers
  1373. (default value 1)
  1374. CFG_ISA_IO_OFFSET
  1375. defines the offset of register from address. It
  1376. depends on which part of the data bus is connected to
  1377. the fdc chipset. (default value 0)
  1378. If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
  1379. CFG_FDC_DRIVE_NUMBER are undefined, they take their
  1380. default value.
  1381. if CFG_FDC_HW_INIT is defined, then the function
  1382. fdc_hw_init() is called at the beginning of the FDC
  1383. setup. fdc_hw_init() must be provided by the board
  1384. source code. It is used to make hardware dependant
  1385. initializations.
  1386. - CFG_IMMR: Physical address of the Internal Memory Mapped
  1387. Register; DO NOT CHANGE! (11-4)
  1388. [MPC8xx systems only]
  1389. - CFG_INIT_RAM_ADDR:
  1390. Start address of memory area that can be used for
  1391. initial data and stack; please note that this must be
  1392. writable memory that is working WITHOUT special
  1393. initialization, i. e. you CANNOT use normal RAM which
  1394. will become available only after programming the
  1395. memory controller and running certain initialization
  1396. sequences.
  1397. U-Boot uses the following memory types:
  1398. - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
  1399. - MPC824X: data cache
  1400. - PPC4xx: data cache
  1401. - CFG_GBL_DATA_OFFSET:
  1402. Offset of the initial data structure in the memory
  1403. area defined by CFG_INIT_RAM_ADDR. Usually
  1404. CFG_GBL_DATA_OFFSET is chosen such that the initial
  1405. data is located at the end of the available space
  1406. (sometimes written as (CFG_INIT_RAM_END -
  1407. CFG_INIT_DATA_SIZE), and the initial stack is just
  1408. below that area (growing from (CFG_INIT_RAM_ADDR +
  1409. CFG_GBL_DATA_OFFSET) downward.
  1410. Note:
  1411. On the MPC824X (or other systems that use the data
  1412. cache for initial memory) the address chosen for
  1413. CFG_INIT_RAM_ADDR is basically arbitrary - it must
  1414. point to an otherwise UNUSED address space between
  1415. the top of RAM and the start of the PCI space.
  1416. - CFG_SIUMCR: SIU Module Configuration (11-6)
  1417. - CFG_SYPCR: System Protection Control (11-9)
  1418. - CFG_TBSCR: Time Base Status and Control (11-26)
  1419. - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
  1420. - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
  1421. - CFG_SCCR: System Clock and reset Control Register (15-27)
  1422. - CFG_OR_TIMING_SDRAM:
  1423. SDRAM timing
  1424. - CFG_MAMR_PTA:
  1425. periodic timer for refresh
  1426. - CFG_DER: Debug Event Register (37-47)
  1427. - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
  1428. CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
  1429. CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
  1430. CFG_BR1_PRELIM:
  1431. Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
  1432. - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
  1433. CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
  1434. CFG_OR3_PRELIM, CFG_BR3_PRELIM:
  1435. Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
  1436. - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
  1437. CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
  1438. Machine Mode Register and Memory Periodic Timer
  1439. Prescaler definitions (SDRAM timing)
  1440. - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
  1441. enable I2C microcode relocation patch (MPC8xx);
  1442. define relocation offset in DPRAM [DSP2]
  1443. - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
  1444. enable SPI microcode relocation patch (MPC8xx);
  1445. define relocation offset in DPRAM [SCC4]
  1446. - CFG_USE_OSCCLK:
  1447. Use OSCM clock mode on MBX8xx board. Be careful,
  1448. wrong setting might damage your board. Read
  1449. doc/README.MBX before setting this variable!
  1450. - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
  1451. Offset of the bootmode word in DPRAM used by post
  1452. (Power On Self Tests). This definition overrides
  1453. #define'd default value in commproc.h resp.
  1454. cpm_8260.h.
  1455. - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
  1456. CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
  1457. CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
  1458. CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
  1459. CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
  1460. CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
  1461. CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
  1462. CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
  1463. Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
  1464. Building the Software:
  1465. ======================
  1466. Building U-Boot has been tested in native PPC environments (on a
  1467. PowerBook G3 running LinuxPPC 2000) and in cross environments
  1468. (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
  1469. NetBSD 1.5 on x86).
  1470. If you are not using a native PPC environment, it is assumed that you
  1471. have the GNU cross compiling tools available in your path and named
  1472. with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
  1473. you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
  1474. the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
  1475. change it to:
  1476. CROSS_COMPILE = ppc_4xx-
  1477. U-Boot is intended to be simple to build. After installing the
  1478. sources you must configure U-Boot for one specific board type. This
  1479. is done by typing:
  1480. make NAME_config
  1481. where "NAME_config" is the name of one of the existing
  1482. configurations; the following names are supported:
  1483. ADCIOP_config GTH_config TQM850L_config
  1484. ADS860_config IP860_config TQM855L_config
  1485. AR405_config IVML24_config TQM860L_config
  1486. CANBT_config IVMS8_config WALNUT405_config
  1487. CPCI405_config LANTEC_config cogent_common_config
  1488. CPCIISER4_config MBX_config cogent_mpc8260_config
  1489. CU824_config MBX860T_config cogent_mpc8xx_config
  1490. ESTEEM192E_config RPXlite_config hermes_config
  1491. ETX094_config RPXsuper_config hymod_config
  1492. FADS823_config SM850_config lwmon_config
  1493. FADS850SAR_config SPD823TS_config pcu_e_config
  1494. FADS860T_config SXNI855T_config rsdproto_config
  1495. FPS850L_config Sandpoint8240_config sbc8260_config
  1496. GENIETV_config TQM823L_config PIP405_config
  1497. GEN860T_config EBONY_config FPS860L_config
  1498. ELPT860_config cmi_mpc5xx_config NETVIA_config
  1499. at91rm9200dk_config omap1510inn_config MPC8260ADS_config
  1500. omap1610inn_config
  1501. Note: for some board special configuration names may exist; check if
  1502. additional information is available from the board vendor; for
  1503. instance, the TQM8xxL systems run normally at 50 MHz and use a
  1504. SCC for 10baseT ethernet; there are also systems with 80 MHz
  1505. CPU clock, and an optional Fast Ethernet module is available
  1506. for CPU's with FEC. You can select such additional "features"
  1507. when chosing the configuration, i. e.
  1508. make TQM860L_config
  1509. - will configure for a plain TQM860L, i. e. 50MHz, no FEC
  1510. make TQM860L_FEC_config
  1511. - will configure for a TQM860L at 50MHz with FEC for ethernet
  1512. make TQM860L_80MHz_config
  1513. - will configure for a TQM860L at 80 MHz, with normal 10baseT
  1514. interface
  1515. make TQM860L_FEC_80MHz_config
  1516. - will configure for a TQM860L at 80 MHz with FEC for ethernet
  1517. make TQM823L_LCD_config
  1518. - will configure for a TQM823L with U-Boot console on LCD
  1519. make TQM823L_LCD_80MHz_config
  1520. - will configure for a TQM823L at 80 MHz with U-Boot console on LCD
  1521. etc.
  1522. Finally, type "make all", and you should get some working U-Boot
  1523. images ready for download to / installation on your system:
  1524. - "u-boot.bin" is a raw binary image
  1525. - "u-boot" is an image in ELF binary format
  1526. - "u-boot.srec" is in Motorola S-Record format
  1527. Please be aware that the Makefiles assume you are using GNU make, so
  1528. for instance on NetBSD you might need to use "gmake" instead of
  1529. native "make".
  1530. If the system board that you have is not listed, then you will need
  1531. to port U-Boot to your hardware platform. To do this, follow these
  1532. steps:
  1533. 1. Add a new configuration option for your board to the toplevel
  1534. "Makefile" and to the "MAKEALL" script, using the existing
  1535. entries as examples. Note that here and at many other places
  1536. boards and other names are listed in alphabetical sort order. Please
  1537. keep this order.
  1538. 2. Create a new directory to hold your board specific code. Add any
  1539. files you need. In your board directory, you will need at least
  1540. the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
  1541. 3. Create a new configuration file "include/configs/<board>.h" for
  1542. your board
  1543. 3. If you're porting U-Boot to a new CPU, then also create a new
  1544. directory to hold your CPU specific code. Add any files you need.
  1545. 4. Run "make <board>_config" with your new name.
  1546. 5. Type "make", and you should get a working "u-boot.srec" file
  1547. to be installed on your target system.
  1548. 6. Debug and solve any problems that might arise.
  1549. [Of course, this last step is much harder than it sounds.]
  1550. Testing of U-Boot Modifications, Ports to New Hardware, etc.:
  1551. ==============================================================
  1552. If you have modified U-Boot sources (for instance added a new board
  1553. or support for new devices, a new CPU, etc.) you are expected to
  1554. provide feedback to the other developers. The feedback normally takes
  1555. the form of a "patch", i. e. a context diff against a certain (latest
  1556. official or latest in CVS) version of U-Boot sources.
  1557. But before you submit such a patch, please verify that your modifi-
  1558. cation did not break existing code. At least make sure that *ALL* of
  1559. the supported boards compile WITHOUT ANY compiler warnings. To do so,
  1560. just run the "MAKEALL" script, which will configure and build U-Boot
  1561. for ALL supported system. Be warned, this will take a while. You can
  1562. select which (cross) compiler to use by passing a `CROSS_COMPILE'
  1563. environment variable to the script, i. e. to use the cross tools from
  1564. MontaVista's Hard Hat Linux you can type
  1565. CROSS_COMPILE=ppc_8xx- MAKEALL
  1566. or to build on a native PowerPC system you can type
  1567. CROSS_COMPILE=' ' MAKEALL
  1568. See also "U-Boot Porting Guide" below.
  1569. Monitor Commands - Overview:
  1570. ============================
  1571. go - start application at address 'addr'
  1572. run - run commands in an environment variable
  1573. bootm - boot application image from memory
  1574. bootp - boot image via network using BootP/TFTP protocol
  1575. tftpboot- boot image via network using TFTP protocol
  1576. and env variables "ipaddr" and "serverip"
  1577. (and eventually "gatewayip")
  1578. rarpboot- boot image via network using RARP/TFTP protocol
  1579. diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
  1580. loads - load S-Record file over serial line
  1581. loadb - load binary file over serial line (kermit mode)
  1582. md - memory display
  1583. mm - memory modify (auto-incrementing)
  1584. nm - memory modify (constant address)
  1585. mw - memory write (fill)
  1586. cp - memory copy
  1587. cmp - memory compare
  1588. crc32 - checksum calculation
  1589. imd - i2c memory display
  1590. imm - i2c memory modify (auto-incrementing)
  1591. inm - i2c memory modify (constant address)
  1592. imw - i2c memory write (fill)
  1593. icrc32 - i2c checksum calculation
  1594. iprobe - probe to discover valid I2C chip addresses
  1595. iloop - infinite loop on address range
  1596. isdram - print SDRAM configuration information
  1597. sspi - SPI utility commands
  1598. base - print or set address offset
  1599. printenv- print environment variables
  1600. setenv - set environment variables
  1601. saveenv - save environment variables to persistent storage
  1602. protect - enable or disable FLASH write protection
  1603. erase - erase FLASH memory
  1604. flinfo - print FLASH memory information
  1605. bdinfo - print Board Info structure
  1606. iminfo - print header information for application image
  1607. coninfo - print console devices and informations
  1608. ide - IDE sub-system
  1609. loop - infinite loop on address range
  1610. mtest - simple RAM test
  1611. icache - enable or disable instruction cache
  1612. dcache - enable or disable data cache
  1613. reset - Perform RESET of the CPU
  1614. echo - echo args to console
  1615. version - print monitor version
  1616. help - print online help
  1617. ? - alias for 'help'
  1618. Monitor Commands - Detailed Description:
  1619. ========================================
  1620. TODO.
  1621. For now: just type "help <command>".
  1622. Environment Variables:
  1623. ======================
  1624. U-Boot supports user configuration using Environment Variables which
  1625. can be made persistent by saving to Flash memory.
  1626. Environment Variables are set using "setenv", printed using
  1627. "printenv", and saved to Flash using "saveenv". Using "setenv"
  1628. without a value can be used to delete a variable from the
  1629. environment. As long as you don't save the environment you are
  1630. working with an in-memory copy. In case the Flash area containing the
  1631. environment is erased by accident, a default environment is provided.
  1632. Some configuration options can be set using Environment Variables:
  1633. baudrate - see CONFIG_BAUDRATE
  1634. bootdelay - see CONFIG_BOOTDELAY
  1635. bootcmd - see CONFIG_BOOTCOMMAND
  1636. bootargs - Boot arguments when booting an RTOS image
  1637. bootfile - Name of the image to load with TFTP
  1638. autoload - if set to "no" (any string beginning with 'n'),
  1639. "bootp" will just load perform a lookup of the
  1640. configuration from the BOOTP server, but not try to
  1641. load any image using TFTP
  1642. autostart - if set to "yes", an image loaded using the "bootp",
  1643. "rarpboot", "tftpboot" or "diskboot" commands will
  1644. be automatically started (by internally calling
  1645. "bootm")
  1646. If set to "no", a standalone image passed to the
  1647. "bootm" command will be copied to the load address
  1648. (and eventually uncompressed), but NOT be started.
  1649. This can be used to load and uncompress arbitrary
  1650. data.
  1651. initrd_high - restrict positioning of initrd images:
  1652. If this variable is not set, initrd images will be
  1653. copied to the highest possible address in RAM; this
  1654. is usually what you want since it allows for
  1655. maximum initrd size. If for some reason you want to
  1656. make sure that the initrd image is loaded below the
  1657. CFG_BOOTMAPSZ limit, you can set this environment
  1658. variable to a value of "no" or "off" or "0".
  1659. Alternatively, you can set it to a maximum upper
  1660. address to use (U-Boot will still check that it
  1661. does not overwrite the U-Boot stack and data).
  1662. For instance, when you have a system with 16 MB
  1663. RAM, and want to reserve 4 MB from use by Linux,
  1664. you can do this by adding "mem=12M" to the value of
  1665. the "bootargs" variable. However, now you must make
  1666. sure that the initrd image is placed in the first
  1667. 12 MB as well - this can be done with
  1668. setenv initrd_high 00c00000
  1669. If you set initrd_high to 0xFFFFFFFF, this is an
  1670. indication to U-Boot that all addresses are legal
  1671. for the Linux kernel, including addresses in flash
  1672. memory. In this case U-Boot will NOT COPY the
  1673. ramdisk at all. This may be useful to reduce the
  1674. boot time on your system, but requires that this
  1675. feature is supported by your Linux kernel.
  1676. ipaddr - IP address; needed for tftpboot command
  1677. loadaddr - Default load address for commands like "bootp",
  1678. "rarpboot", "tftpboot", "loadb" or "diskboot"
  1679. loads_echo - see CONFIG_LOADS_ECHO
  1680. serverip - TFTP server IP address; needed for tftpboot command
  1681. bootretry - see CONFIG_BOOT_RETRY_TIME
  1682. bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
  1683. bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
  1684. The following environment variables may be used and automatically
  1685. updated by the network boot commands ("bootp" and "rarpboot"),
  1686. depending the information provided by your boot server:
  1687. bootfile - see above
  1688. dnsip - IP address of your Domain Name Server
  1689. dnsip2 - IP address of your secondary Domain Name Server
  1690. gatewayip - IP address of the Gateway (Router) to use
  1691. hostname - Target hostname
  1692. ipaddr - see above
  1693. netmask - Subnet Mask
  1694. rootpath - Pathname of the root filesystem on the NFS server
  1695. serverip - see above
  1696. There are two special Environment Variables:
  1697. serial# - contains hardware identification information such
  1698. as type string and/or serial number
  1699. ethaddr - Ethernet address
  1700. These variables can be set only once (usually during manufacturing of
  1701. the board). U-Boot refuses to delete or overwrite these variables
  1702. once they have been set once.
  1703. Further special Environment Variables:
  1704. ver - Contains the U-Boot version string as printed
  1705. with the "version" command. This variable is
  1706. readonly (see CONFIG_VERSION_VARIABLE).
  1707. Please note that changes to some configuration parameters may take
  1708. only effect after the next boot (yes, that's just like Windoze :-).
  1709. Command Line Parsing:
  1710. =====================
  1711. There are two different command line parsers available with U-Boot:
  1712. the old "simple" one, and the much more powerful "hush" shell:
  1713. Old, simple command line parser:
  1714. --------------------------------
  1715. - supports environment variables (through setenv / saveenv commands)
  1716. - several commands on one line, separated by ';'
  1717. - variable substitution using "... $(name) ..." syntax
  1718. - special characters ('$', ';') can be escaped by prefixing with '\',
  1719. for example:
  1720. setenv bootcmd bootm \$(address)
  1721. - You can also escape text by enclosing in single apostrophes, for example:
  1722. setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
  1723. Hush shell:
  1724. -----------
  1725. - similar to Bourne shell, with control structures like
  1726. if...then...else...fi, for...do...done; while...do...done,
  1727. until...do...done, ...
  1728. - supports environment ("global") variables (through setenv / saveenv
  1729. commands) and local shell variables (through standard shell syntax
  1730. "name=value"); only environment variables can be used with "run"
  1731. command
  1732. General rules:
  1733. --------------
  1734. (1) If a command line (or an environment variable executed by a "run"
  1735. command) contains several commands separated by semicolon, and
  1736. one of these commands fails, then the remaining commands will be
  1737. executed anyway.
  1738. (2) If you execute several variables with one call to run (i. e.
  1739. calling run with a list af variables as arguments), any failing
  1740. command will cause "run" to terminate, i. e. the remaining
  1741. variables are not executed.
  1742. Note for Redundant Ethernet Interfaces:
  1743. =======================================
  1744. Some boards come with redundant ethernet interfaces; U-Boot supports
  1745. such configurations and is capable of automatic selection of a
  1746. "working" interface when needed. MAC assignment works as follows:
  1747. Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
  1748. MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
  1749. "eth1addr" (=>eth1), "eth2addr", ...
  1750. If the network interface stores some valid MAC address (for instance
  1751. in SROM), this is used as default address if there is NO correspon-
  1752. ding setting in the environment; if the corresponding environment
  1753. variable is set, this overrides the settings in the card; that means:
  1754. o If the SROM has a valid MAC address, and there is no address in the
  1755. environment, the SROM's address is used.
  1756. o If there is no valid address in the SROM, and a definition in the
  1757. environment exists, then the value from the environment variable is
  1758. used.
  1759. o If both the SROM and the environment contain a MAC address, and
  1760. both addresses are the same, this MAC address is used.
  1761. o If both the SROM and the environment contain a MAC address, and the
  1762. addresses differ, the value from the environment is used and a
  1763. warning is printed.
  1764. o If neither SROM nor the environment contain a MAC address, an error
  1765. is raised.
  1766. Image Formats:
  1767. ==============
  1768. The "boot" commands of this monitor operate on "image" files which
  1769. can be basicly anything, preceeded by a special header; see the
  1770. definitions in include/image.h for details; basicly, the header
  1771. defines the following image properties:
  1772. * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
  1773. 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
  1774. LynxOS, pSOS, QNX, RTEMS, ARTOS;
  1775. Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
  1776. * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
  1777. IA64, MIPS, MIPS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
  1778. Currently supported: PowerPC).
  1779. * Compression Type (uncompressed, gzip, bzip2)
  1780. * Load Address
  1781. * Entry Point
  1782. * Image Name
  1783. * Image Timestamp
  1784. The header is marked by a special Magic Number, and both the header
  1785. and the data portions of the image are secured against corruption by
  1786. CRC32 checksums.
  1787. Linux Support:
  1788. ==============
  1789. Although U-Boot should support any OS or standalone application
  1790. easily, the main focus has always been on Linux during the design of
  1791. U-Boot.
  1792. U-Boot includes many features that so far have been part of some
  1793. special "boot loader" code within the Linux kernel. Also, any
  1794. "initrd" images to be used are no longer part of one big Linux image;
  1795. instead, kernel and "initrd" are separate images. This implementation
  1796. serves several purposes:
  1797. - the same features can be used for other OS or standalone
  1798. applications (for instance: using compressed images to reduce the
  1799. Flash memory footprint)
  1800. - it becomes much easier to port new Linux kernel versions because
  1801. lots of low-level, hardware dependent stuff are done by U-Boot
  1802. - the same Linux kernel image can now be used with different "initrd"
  1803. images; of course this also means that different kernel images can
  1804. be run with the same "initrd". This makes testing easier (you don't
  1805. have to build a new "zImage.initrd" Linux image when you just
  1806. change a file in your "initrd"). Also, a field-upgrade of the
  1807. software is easier now.
  1808. Linux HOWTO:
  1809. ============
  1810. Porting Linux to U-Boot based systems:
  1811. ---------------------------------------
  1812. U-Boot cannot save you from doing all the necessary modifications to
  1813. configure the Linux device drivers for use with your target hardware
  1814. (no, we don't intend to provide a full virtual machine interface to
  1815. Linux :-).
  1816. But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
  1817. Just make sure your machine specific header file (for instance
  1818. include/asm-ppc/tqm8xx.h) includes the same definition of the Board
  1819. Information structure as we define in include/u-boot.h, and make
  1820. sure that your definition of IMAP_ADDR uses the same value as your
  1821. U-Boot configuration in CFG_IMMR.
  1822. Configuring the Linux kernel:
  1823. -----------------------------
  1824. No specific requirements for U-Boot. Make sure you have some root
  1825. device (initial ramdisk, NFS) for your target system.
  1826. Building a Linux Image:
  1827. -----------------------
  1828. With U-Boot, "normal" build targets like "zImage" or "bzImage" are
  1829. not used. If you use recent kernel source, a new build target
  1830. "uImage" will exist which automatically builds an image usable by
  1831. U-Boot. Most older kernels also have support for a "pImage" target,
  1832. which was introduced for our predecessor project PPCBoot and uses a
  1833. 100% compatible format.
  1834. Example:
  1835. make TQM850L_config
  1836. make oldconfig
  1837. make dep
  1838. make uImage
  1839. The "uImage" build target uses a special tool (in 'tools/mkimage') to
  1840. encapsulate a compressed Linux kernel image with header information,
  1841. CRC32 checksum etc. for use with U-Boot. This is what we are doing:
  1842. * build a standard "vmlinux" kernel image (in ELF binary format):
  1843. * convert the kernel into a raw binary image:
  1844. ${CROSS_COMPILE}-objcopy -O binary \
  1845. -R .note -R .comment \
  1846. -S vmlinux linux.bin
  1847. * compress the binary image:
  1848. gzip -9 linux.bin
  1849. * package compressed binary image for U-Boot:
  1850. mkimage -A ppc -O linux -T kernel -C gzip \
  1851. -a 0 -e 0 -n "Linux Kernel Image" \
  1852. -d linux.bin.gz uImage
  1853. The "mkimage" tool can also be used to create ramdisk images for use
  1854. with U-Boot, either separated from the Linux kernel image, or
  1855. combined into one file. "mkimage" encapsulates the images with a 64
  1856. byte header containing information about target architecture,
  1857. operating system, image type, compression method, entry points, time
  1858. stamp, CRC32 checksums, etc.
  1859. "mkimage" can be called in two ways: to verify existing images and
  1860. print the header information, or to build new images.
  1861. In the first form (with "-l" option) mkimage lists the information
  1862. contained in the header of an existing U-Boot image; this includes
  1863. checksum verification:
  1864. tools/mkimage -l image
  1865. -l ==> list image header information
  1866. The second form (with "-d" option) is used to build a U-Boot image
  1867. from a "data file" which is used as image payload:
  1868. tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
  1869. -n name -d data_file image
  1870. -A ==> set architecture to 'arch'
  1871. -O ==> set operating system to 'os'
  1872. -T ==> set image type to 'type'
  1873. -C ==> set compression type 'comp'
  1874. -a ==> set load address to 'addr' (hex)
  1875. -e ==> set entry point to 'ep' (hex)
  1876. -n ==> set image name to 'name'
  1877. -d ==> use image data from 'datafile'
  1878. Right now, all Linux kernels use the same load address (0x00000000),
  1879. but the entry point address depends on the kernel version:
  1880. - 2.2.x kernels have the entry point at 0x0000000C,
  1881. - 2.3.x and later kernels have the entry point at 0x00000000.
  1882. So a typical call to build a U-Boot image would read:
  1883. -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
  1884. > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
  1885. > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
  1886. > examples/uImage.TQM850L
  1887. Image Name: 2.4.4 kernel for TQM850L
  1888. Created: Wed Jul 19 02:34:59 2000
  1889. Image Type: PowerPC Linux Kernel Image (gzip compressed)
  1890. Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
  1891. Load Address: 0x00000000
  1892. Entry Point: 0x00000000
  1893. To verify the contents of the image (or check for corruption):
  1894. -> tools/mkimage -l examples/uImage.TQM850L
  1895. Image Name: 2.4.4 kernel for TQM850L
  1896. Created: Wed Jul 19 02:34:59 2000
  1897. Image Type: PowerPC Linux Kernel Image (gzip compressed)
  1898. Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
  1899. Load Address: 0x00000000
  1900. Entry Point: 0x00000000
  1901. NOTE: for embedded systems where boot time is critical you can trade
  1902. speed for memory and install an UNCOMPRESSED image instead: this
  1903. needs more space in Flash, but boots much faster since it does not
  1904. need to be uncompressed:
  1905. -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
  1906. -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
  1907. > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
  1908. > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
  1909. > examples/uImage.TQM850L-uncompressed
  1910. Image Name: 2.4.4 kernel for TQM850L
  1911. Created: Wed Jul 19 02:34:59 2000
  1912. Image Type: PowerPC Linux Kernel Image (uncompressed)
  1913. Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
  1914. Load Address: 0x00000000
  1915. Entry Point: 0x00000000
  1916. Similar you can build U-Boot images from a 'ramdisk.image.gz' file
  1917. when your kernel is intended to use an initial ramdisk:
  1918. -> tools/mkimage -n 'Simple Ramdisk Image' \
  1919. > -A ppc -O linux -T ramdisk -C gzip \
  1920. > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
  1921. Image Name: Simple Ramdisk Image
  1922. Created: Wed Jan 12 14:01:50 2000
  1923. Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
  1924. Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
  1925. Load Address: 0x00000000
  1926. Entry Point: 0x00000000
  1927. Installing a Linux Image:
  1928. -------------------------
  1929. To downloading a U-Boot image over the serial (console) interface,
  1930. you must convert the image to S-Record format:
  1931. objcopy -I binary -O srec examples/image examples/image.srec
  1932. The 'objcopy' does not understand the information in the U-Boot
  1933. image header, so the resulting S-Record file will be relative to
  1934. address 0x00000000. To load it to a given address, you need to
  1935. specify the target address as 'offset' parameter with the 'loads'
  1936. command.
  1937. Example: install the image to address 0x40100000 (which on the
  1938. TQM8xxL is in the first Flash bank):
  1939. => erase 40100000 401FFFFF
  1940. .......... done
  1941. Erased 8 sectors
  1942. => loads 40100000
  1943. ## Ready for S-Record download ...
  1944. ~>examples/image.srec
  1945. 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
  1946. ...
  1947. 15989 15990 15991 15992
  1948. [file transfer complete]
  1949. [connected]
  1950. ## Start Addr = 0x00000000
  1951. You can check the success of the download using the 'iminfo' command;
  1952. this includes a checksum verification so you can be sure no data
  1953. corruption happened:
  1954. => imi 40100000
  1955. ## Checking Image at 40100000 ...
  1956. Image Name: 2.2.13 for initrd on TQM850L
  1957. Image Type: PowerPC Linux Kernel Image (gzip compressed)
  1958. Data Size: 335725 Bytes = 327 kB = 0 MB
  1959. Load Address: 00000000
  1960. Entry Point: 0000000c
  1961. Verifying Checksum ... OK
  1962. Boot Linux:
  1963. -----------
  1964. The "bootm" command is used to boot an application that is stored in
  1965. memory (RAM or Flash). In case of a Linux kernel image, the contents
  1966. of the "bootargs" environment variable is passed to the kernel as
  1967. parameters. You can check and modify this variable using the
  1968. "printenv" and "setenv" commands:
  1969. => printenv bootargs
  1970. bootargs=root=/dev/ram
  1971. => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
  1972. => printenv bootargs
  1973. bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
  1974. => bootm 40020000
  1975. ## Booting Linux kernel at 40020000 ...
  1976. Image Name: 2.2.13 for NFS on TQM850L
  1977. Image Type: PowerPC Linux Kernel Image (gzip compressed)
  1978. Data Size: 381681 Bytes = 372 kB = 0 MB
  1979. Load Address: 00000000
  1980. Entry Point: 0000000c
  1981. Verifying Checksum ... OK
  1982. Uncompressing Kernel Image ... OK
  1983. 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
  1984. Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
  1985. time_init: decrementer frequency = 187500000/60
  1986. Calibrating delay loop... 49.77 BogoMIPS
  1987. Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
  1988. ...
  1989. If you want to boot a Linux kernel with initial ram disk, you pass
  1990. the memory addresses of both the kernel and the initrd image (PPBCOOT
  1991. format!) to the "bootm" command:
  1992. => imi 40100000 40200000
  1993. ## Checking Image at 40100000 ...
  1994. Image Name: 2.2.13 for initrd on TQM850L
  1995. Image Type: PowerPC Linux Kernel Image (gzip compressed)
  1996. Data Size: 335725 Bytes = 327 kB = 0 MB
  1997. Load Address: 00000000
  1998. Entry Point: 0000000c
  1999. Verifying Checksum ... OK
  2000. ## Checking Image at 40200000 ...
  2001. Image Name: Simple Ramdisk Image
  2002. Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
  2003. Data Size: 566530 Bytes = 553 kB = 0 MB
  2004. Load Address: 00000000
  2005. Entry Point: 00000000
  2006. Verifying Checksum ... OK
  2007. => bootm 40100000 40200000
  2008. ## Booting Linux kernel at 40100000 ...
  2009. Image Name: 2.2.13 for initrd on TQM850L
  2010. Image Type: PowerPC Linux Kernel Image (gzip compressed)
  2011. Data Size: 335725 Bytes = 327 kB = 0 MB
  2012. Load Address: 00000000
  2013. Entry Point: 0000000c
  2014. Verifying Checksum ... OK
  2015. Uncompressing Kernel Image ... OK
  2016. ## Loading RAMDisk Image at 40200000 ...
  2017. Image Name: Simple Ramdisk Image
  2018. Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
  2019. Data Size: 566530 Bytes = 553 kB = 0 MB
  2020. Load Address: 00000000
  2021. Entry Point: 00000000
  2022. Verifying Checksum ... OK
  2023. Loading Ramdisk ... OK
  2024. 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
  2025. Boot arguments: root=/dev/ram
  2026. time_init: decrementer frequency = 187500000/60
  2027. Calibrating delay loop... 49.77 BogoMIPS
  2028. ...
  2029. RAMDISK: Compressed image found at block 0
  2030. VFS: Mounted root (ext2 filesystem).
  2031. bash#
  2032. More About U-Boot Image Types:
  2033. ------------------------------
  2034. U-Boot supports the following image types:
  2035. "Standalone Programs" are directly runnable in the environment
  2036. provided by U-Boot; it is expected that (if they behave
  2037. well) you can continue to work in U-Boot after return from
  2038. the Standalone Program.
  2039. "OS Kernel Images" are usually images of some Embedded OS which
  2040. will take over control completely. Usually these programs
  2041. will install their own set of exception handlers, device
  2042. drivers, set up the MMU, etc. - this means, that you cannot
  2043. expect to re-enter U-Boot except by resetting the CPU.
  2044. "RAMDisk Images" are more or less just data blocks, and their
  2045. parameters (address, size) are passed to an OS kernel that is
  2046. being started.
  2047. "Multi-File Images" contain several images, typically an OS
  2048. (Linux) kernel image and one or more data images like
  2049. RAMDisks. This construct is useful for instance when you want
  2050. to boot over the network using BOOTP etc., where the boot
  2051. server provides just a single image file, but you want to get
  2052. for instance an OS kernel and a RAMDisk image.
  2053. "Multi-File Images" start with a list of image sizes, each
  2054. image size (in bytes) specified by an "uint32_t" in network
  2055. byte order. This list is terminated by an "(uint32_t)0".
  2056. Immediately after the terminating 0 follow the images, one by
  2057. one, all aligned on "uint32_t" boundaries (size rounded up to
  2058. a multiple of 4 bytes).
  2059. "Firmware Images" are binary images containing firmware (like
  2060. U-Boot or FPGA images) which usually will be programmed to
  2061. flash memory.
  2062. "Script files" are command sequences that will be executed by
  2063. U-Boot's command interpreter; this feature is especially
  2064. useful when you configure U-Boot to use a real shell (hush)
  2065. as command interpreter.
  2066. Standalone HOWTO:
  2067. =================
  2068. One of the features of U-Boot is that you can dynamically load and
  2069. run "standalone" applications, which can use some resources of
  2070. U-Boot like console I/O functions or interrupt services.
  2071. Two simple examples are included with the sources:
  2072. "Hello World" Demo:
  2073. -------------------
  2074. 'examples/hello_world.c' contains a small "Hello World" Demo
  2075. application; it is automatically compiled when you build U-Boot.
  2076. It's configured to run at address 0x00040004, so you can play with it
  2077. like that:
  2078. => loads
  2079. ## Ready for S-Record download ...
  2080. ~>examples/hello_world.srec
  2081. 1 2 3 4 5 6 7 8 9 10 11 ...
  2082. [file transfer complete]
  2083. [connected]
  2084. ## Start Addr = 0x00040004
  2085. => go 40004 Hello World! This is a test.
  2086. ## Starting application at 0x00040004 ...
  2087. Hello World
  2088. argc = 7
  2089. argv[0] = "40004"
  2090. argv[1] = "Hello"
  2091. argv[2] = "World!"
  2092. argv[3] = "This"
  2093. argv[4] = "is"
  2094. argv[5] = "a"
  2095. argv[6] = "test."
  2096. argv[7] = "<NULL>"
  2097. Hit any key to exit ...
  2098. ## Application terminated, rc = 0x0
  2099. Another example, which demonstrates how to register a CPM interrupt
  2100. handler with the U-Boot code, can be found in 'examples/timer.c'.
  2101. Here, a CPM timer is set up to generate an interrupt every second.
  2102. The interrupt service routine is trivial, just printing a '.'
  2103. character, but this is just a demo program. The application can be
  2104. controlled by the following keys:
  2105. ? - print current values og the CPM Timer registers
  2106. b - enable interrupts and start timer
  2107. e - stop timer and disable interrupts
  2108. q - quit application
  2109. => loads
  2110. ## Ready for S-Record download ...
  2111. ~>examples/timer.srec
  2112. 1 2 3 4 5 6 7 8 9 10 11 ...
  2113. [file transfer complete]
  2114. [connected]
  2115. ## Start Addr = 0x00040004
  2116. => go 40004
  2117. ## Starting application at 0x00040004 ...
  2118. TIMERS=0xfff00980
  2119. Using timer 1
  2120. tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
  2121. Hit 'b':
  2122. [q, b, e, ?] Set interval 1000000 us
  2123. Enabling timer
  2124. Hit '?':
  2125. [q, b, e, ?] ........
  2126. tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
  2127. Hit '?':
  2128. [q, b, e, ?] .
  2129. tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
  2130. Hit '?':
  2131. [q, b, e, ?] .
  2132. tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
  2133. Hit '?':
  2134. [q, b, e, ?] .
  2135. tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
  2136. Hit 'e':
  2137. [q, b, e, ?] ...Stopping timer
  2138. Hit 'q':
  2139. [q, b, e, ?] ## Application terminated, rc = 0x0
  2140. Minicom warning:
  2141. ================
  2142. Over time, many people have reported problems when trying to use the
  2143. "minicom" terminal emulation program for serial download. I (wd)
  2144. consider minicom to be broken, and recommend not to use it. Under
  2145. Unix, I recommend to use C-Kermit for general purpose use (and
  2146. especially for kermit binary protocol download ("loadb" command), and
  2147. use "cu" for S-Record download ("loads" command).
  2148. Nevertheless, if you absolutely want to use it try adding this
  2149. configuration to your "File transfer protocols" section:
  2150. Name Program Name U/D FullScr IO-Red. Multi
  2151. X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
  2152. Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
  2153. NetBSD Notes:
  2154. =============
  2155. Starting at version 0.9.2, U-Boot supports NetBSD both as host
  2156. (build U-Boot) and target system (boots NetBSD/mpc8xx).
  2157. Building requires a cross environment; it is known to work on
  2158. NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
  2159. need gmake since the Makefiles are not compatible with BSD make).
  2160. Note that the cross-powerpc package does not install include files;
  2161. attempting to build U-Boot will fail because <machine/ansi.h> is
  2162. missing. This file has to be installed and patched manually:
  2163. # cd /usr/pkg/cross/powerpc-netbsd/include
  2164. # mkdir powerpc
  2165. # ln -s powerpc machine
  2166. # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
  2167. # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
  2168. Native builds *don't* work due to incompatibilities between native
  2169. and U-Boot include files.
  2170. Booting assumes that (the first part of) the image booted is a
  2171. stage-2 loader which in turn loads and then invokes the kernel
  2172. proper. Loader sources will eventually appear in the NetBSD source
  2173. tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
  2174. meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for
  2175. details.
  2176. Implementation Internals:
  2177. =========================
  2178. The following is not intended to be a complete description of every
  2179. implementation detail. However, it should help to understand the
  2180. inner workings of U-Boot and make it easier to port it to custom
  2181. hardware.
  2182. Initial Stack, Global Data:
  2183. ---------------------------
  2184. The implementation of U-Boot is complicated by the fact that U-Boot
  2185. starts running out of ROM (flash memory), usually without access to
  2186. system RAM (because the memory controller is not initialized yet).
  2187. This means that we don't have writable Data or BSS segments, and BSS
  2188. is not initialized as zero. To be able to get a C environment working
  2189. at all, we have to allocate at least a minimal stack. Implementation
  2190. options for this are defined and restricted by the CPU used: Some CPU
  2191. models provide on-chip memory (like the IMMR area on MPC8xx and
  2192. MPC826x processors), on others (parts of) the data cache can be
  2193. locked as (mis-) used as memory, etc.
  2194. Chris Hallinan posted a good summary of these issues to the
  2195. u-boot-users mailing list:
  2196. Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
  2197. From: "Chris Hallinan" <clh@net1plus.com>
  2198. Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
  2199. ...
  2200. Correct me if I'm wrong, folks, but the way I understand it
  2201. is this: Using DCACHE as initial RAM for Stack, etc, does not
  2202. require any physical RAM backing up the cache. The cleverness
  2203. is that the cache is being used as a temporary supply of
  2204. necessary storage before the SDRAM controller is setup. It's
  2205. beyond the scope of this list to expain the details, but you
  2206. can see how this works by studying the cache architecture and
  2207. operation in the architecture and processor-specific manuals.
  2208. OCM is On Chip Memory, which I believe the 405GP has 4K. It
  2209. is another option for the system designer to use as an
  2210. initial stack/ram area prior to SDRAM being available. Either
  2211. option should work for you. Using CS 4 should be fine if your
  2212. board designers haven't used it for something that would
  2213. cause you grief during the initial boot! It is frequently not
  2214. used.
  2215. CFG_INIT_RAM_ADDR should be somewhere that won't interfere
  2216. with your processor/board/system design. The default value
  2217. you will find in any recent u-boot distribution in
  2218. Walnut405.h should work for you. I'd set it to a value larger
  2219. than your SDRAM module. If you have a 64MB SDRAM module, set
  2220. it above 400_0000. Just make sure your board has no resources
  2221. that are supposed to respond to that address! That code in
  2222. start.S has been around a while and should work as is when
  2223. you get the config right.
  2224. -Chris Hallinan
  2225. DS4.COM, Inc.
  2226. It is essential to remember this, since it has some impact on the C
  2227. code for the initialization procedures:
  2228. * Initialized global data (data segment) is read-only. Do not attempt
  2229. to write it.
  2230. * Do not use any unitialized global data (or implicitely initialized
  2231. as zero data - BSS segment) at all - this is undefined, initiali-
  2232. zation is performed later (when relocating to RAM).
  2233. * Stack space is very limited. Avoid big data buffers or things like
  2234. that.
  2235. Having only the stack as writable memory limits means we cannot use
  2236. normal global data to share information beween the code. But it
  2237. turned out that the implementation of U-Boot can be greatly
  2238. simplified by making a global data structure (gd_t) available to all
  2239. functions. We could pass a pointer to this data as argument to _all_
  2240. functions, but this would bloat the code. Instead we use a feature of
  2241. the GCC compiler (Global Register Variables) to share the data: we
  2242. place a pointer (gd) to the global data into a register which we
  2243. reserve for this purpose.
  2244. When choosing a register for such a purpose we are restricted by the
  2245. relevant (E)ABI specifications for the current architecture, and by
  2246. GCC's implementation.
  2247. For PowerPC, the following registers have specific use:
  2248. R1: stack pointer
  2249. R2: TOC pointer
  2250. R3-R4: parameter passing and return values
  2251. R5-R10: parameter passing
  2252. R13: small data area pointer
  2253. R30: GOT pointer
  2254. R31: frame pointer
  2255. (U-Boot also uses R14 as internal GOT pointer.)
  2256. ==> U-Boot will use R29 to hold a pointer to the global data
  2257. Note: on PPC, we could use a static initializer (since the
  2258. address of the global data structure is known at compile time),
  2259. but it turned out that reserving a register results in somewhat
  2260. smaller code - although the code savings are not that big (on
  2261. average for all boards 752 bytes for the whole U-Boot image,
  2262. 624 text + 127 data).
  2263. On ARM, the following registers are used:
  2264. R0: function argument word/integer result
  2265. R1-R3: function argument word
  2266. R9: GOT pointer
  2267. R10: stack limit (used only if stack checking if enabled)
  2268. R11: argument (frame) pointer
  2269. R12: temporary workspace
  2270. R13: stack pointer
  2271. R14: link register
  2272. R15: program counter
  2273. ==> U-Boot will use R8 to hold a pointer to the global data
  2274. Memory Management:
  2275. ------------------
  2276. U-Boot runs in system state and uses physical addresses, i.e. the
  2277. MMU is not used either for address mapping nor for memory protection.
  2278. The available memory is mapped to fixed addresses using the memory
  2279. controller. In this process, a contiguous block is formed for each
  2280. memory type (Flash, SDRAM, SRAM), even when it consists of several
  2281. physical memory banks.
  2282. U-Boot is installed in the first 128 kB of the first Flash bank (on
  2283. TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
  2284. booting and sizing and initializing DRAM, the code relocates itself
  2285. to the upper end of DRAM. Immediately below the U-Boot code some
  2286. memory is reserved for use by malloc() [see CFG_MALLOC_LEN
  2287. configuration setting]. Below that, a structure with global Board
  2288. Info data is placed, followed by the stack (growing downward).
  2289. Additionally, some exception handler code is copied to the low 8 kB
  2290. of DRAM (0x00000000 ... 0x00001FFF).
  2291. So a typical memory configuration with 16 MB of DRAM could look like
  2292. this:
  2293. 0x0000 0000 Exception Vector code
  2294. :
  2295. 0x0000 1FFF
  2296. 0x0000 2000 Free for Application Use
  2297. :
  2298. :
  2299. :
  2300. :
  2301. 0x00FB FF20 Monitor Stack (Growing downward)
  2302. 0x00FB FFAC Board Info Data and permanent copy of global data
  2303. 0x00FC 0000 Malloc Arena
  2304. :
  2305. 0x00FD FFFF
  2306. 0x00FE 0000 RAM Copy of Monitor Code
  2307. ... eventually: LCD or video framebuffer
  2308. ... eventually: pRAM (Protected RAM - unchanged by reset)
  2309. 0x00FF FFFF [End of RAM]
  2310. System Initialization:
  2311. ----------------------
  2312. In the reset configuration, U-Boot starts at the reset entry point
  2313. (on most PowerPC systens at address 0x00000100). Because of the reset
  2314. configuration for CS0# this is a mirror of the onboard Flash memory.
  2315. To be able to re-map memory U-Boot then jumps to its link address.
  2316. To be able to implement the initialization code in C, a (small!)
  2317. initial stack is set up in the internal Dual Ported RAM (in case CPUs
  2318. which provide such a feature like MPC8xx or MPC8260), or in a locked
  2319. part of the data cache. After that, U-Boot initializes the CPU core,
  2320. the caches and the SIU.
  2321. Next, all (potentially) available memory banks are mapped using a
  2322. preliminary mapping. For example, we put them on 512 MB boundaries
  2323. (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
  2324. on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
  2325. programmed for SDRAM access. Using the temporary configuration, a
  2326. simple memory test is run that determines the size of the SDRAM
  2327. banks.
  2328. When there is more than one SDRAM bank, and the banks are of
  2329. different size, the largest is mapped first. For equal size, the first
  2330. bank (CS2#) is mapped first. The first mapping is always for address
  2331. 0x00000000, with any additional banks following immediately to create
  2332. contiguous memory starting from 0.
  2333. Then, the monitor installs itself at the upper end of the SDRAM area
  2334. and allocates memory for use by malloc() and for the global Board
  2335. Info data; also, the exception vector code is copied to the low RAM
  2336. pages, and the final stack is set up.
  2337. Only after this relocation will you have a "normal" C environment;
  2338. until that you are restricted in several ways, mostly because you are
  2339. running from ROM, and because the code will have to be relocated to a
  2340. new address in RAM.
  2341. U-Boot Porting Guide:
  2342. ----------------------
  2343. [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
  2344. list, October 2002]
  2345. int main (int argc, char *argv[])
  2346. {
  2347. sighandler_t no_more_time;
  2348. signal (SIGALRM, no_more_time);
  2349. alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
  2350. if (available_money > available_manpower) {
  2351. pay consultant to port U-Boot;
  2352. return 0;
  2353. }
  2354. Download latest U-Boot source;
  2355. Subscribe to u-boot-users mailing list;
  2356. if (clueless) {
  2357. email ("Hi, I am new to U-Boot, how do I get started?");
  2358. }
  2359. while (learning) {
  2360. Read the README file in the top level directory;
  2361. Read http://www.denx.de/re/DPLG.html
  2362. Read the source, Luke;
  2363. }
  2364. if (available_money > toLocalCurrency ($2500)) {
  2365. Buy a BDI2000;
  2366. } else {
  2367. Add a lot of aggravation and time;
  2368. }
  2369. Create your own board support subdirectory;
  2370. Create your own board config file;
  2371. while (!running) {
  2372. do {
  2373. Add / modify source code;
  2374. } until (compiles);
  2375. Debug;
  2376. if (clueless)
  2377. email ("Hi, I am having problems...");
  2378. }
  2379. Send patch file to Wolfgang;
  2380. return 0;
  2381. }
  2382. void no_more_time (int sig)
  2383. {
  2384. hire_a_guru();
  2385. }
  2386. Coding Standards:
  2387. -----------------
  2388. All contributions to U-Boot should conform to the Linux kernel
  2389. coding style; see the file "Documentation/CodingStyle" in your Linux
  2390. kernel source directory.
  2391. Please note that U-Boot is implemented in C (and to some small parts
  2392. in Assembler); no C++ is used, so please do not use C++ style
  2393. comments (//) in your code.
  2394. Submissions which do not conform to the standards may be returned
  2395. with a request to reformat the changes.
  2396. Submitting Patches:
  2397. -------------------
  2398. Since the number of patches for U-Boot is growing, we need to
  2399. establish some rules. Submissions which do not conform to these rules
  2400. may be rejected, even when they contain important and valuable stuff.
  2401. When you send a patch, please include the following information with
  2402. it:
  2403. * For bug fixes: a description of the bug and how your patch fixes
  2404. this bug. Please try to include a way of demonstrating that the
  2405. patch actually fixes something.
  2406. * For new features: a description of the feature and your
  2407. implementation.
  2408. * A CHANGELOG entry as plaintext (separate from the patch)
  2409. * For major contributions, your entry to the CREDITS file
  2410. * When you add support for a new board, don't forget to add this
  2411. board to the MAKEALL script, too.
  2412. * If your patch adds new configuration options, don't forget to
  2413. document these in the README file.
  2414. * The patch itself. If you are accessing the CVS repository use "cvs
  2415. update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
  2416. version of diff does not support these options, then get the latest
  2417. version of GNU diff.
  2418. The current directory when running this command shall be the top
  2419. level directory of the U-Boot source tree, or it's parent directory
  2420. (i. e. please make sure that your patch includes sufficient
  2421. directory information for the affected files).
  2422. We accept patches as plain text, MIME attachments or as uuencoded
  2423. gzipped text.
  2424. * If one logical set of modifications affects or creates several
  2425. files, all these changes shall be submitted in a SINGLE patch file.
  2426. * Changesets that contain different, unrelated modifications shall be
  2427. submitted as SEPARATE patches, one patch per changeset.
  2428. Notes:
  2429. * Before sending the patch, run the MAKEALL script on your patched
  2430. source tree and make sure that no errors or warnings are reported
  2431. for any of the boards.
  2432. * Keep your modifications to the necessary minimum: A patch
  2433. containing several unrelated changes or arbitrary reformats will be
  2434. returned with a request to re-formatting / split it.
  2435. * If you modify existing code, make sure that your new code does not
  2436. add to the memory footprint of the code ;-) Small is beautiful!
  2437. When adding new features, these should compile conditionally only
  2438. (using #ifdef), and the resulting code with the new feature
  2439. disabled must not need more memory than the old code without your
  2440. modification.