| # |
| # (C) Copyright 2000 - 2002 |
| # Wolfgang Denk, DENX Software Engineering, wd@denx.de. |
| # |
| # See file CREDITS for list of people who contributed to this |
| # project. |
| # |
| # This program is free software; you can redistribute it and/or |
| # modify it under the terms of the GNU General Public License as |
| # published by the Free Software Foundation; either version 2 of |
| # the License, or (at your option) any later version. |
| # |
| # This program is distributed in the hope that it will be useful, |
| # but WITHOUT ANY WARRANTY; without even the implied warranty of |
| # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| # GNU General Public License for more details. |
| # |
| # You should have received a copy of the GNU General Public License |
| # along with this program; if not, write to the Free Software |
| # Foundation, Inc., 59 Temple Place, Suite 330, Boston, |
| # MA 02111-1307 USA |
| # |
| |
| Summary: |
| ======== |
| |
| This directory contains the source code for U-Boot, a boot loader for |
| Embedded boards based on PowerPC and ARM processors, which can be |
| installed in a boot ROM and used to initialize and test the hardware |
| or to download and run application code. |
| |
| The development of U-Boot is closely related to Linux: some parts of |
| the source code originate in the Linux source tree, we have some |
| header files in common, and special provision has been made to |
| support booting of Linux images. |
| |
| Some attention has been paid to make this software easily |
| configurable and extendable. For instance, all monitor commands are |
| implemented with the same call interface, so that it's very easy to |
| add new commands. Also, instead of permanently adding rarely used |
| code (for instance hardware test utilities) to the monitor, you can |
| load and run it dynamically. |
| |
| |
| Status: |
| ======= |
| |
| In general, all boards for which a configuration option exists in the |
| Makefile have been tested to some extent and can be considered |
| "working". In fact, many of them are used in production systems. |
| |
| In case of problems see the CHANGELOG and CREDITS files to find out |
| who contributed the specific port. |
| |
| |
| Where to get help: |
| ================== |
| |
| In case you have questions about, problems with or contributions for |
| U-Boot you should send a message to the U-Boot mailing list at |
| <u-boot-users@lists.sourceforge.net>. There is also an archive of |
| previous traffic on the mailing list - please search the archive |
| before asking FAQ's. Please see |
| http://lists.sourceforge.net/lists/listinfo/u-boot-users/ |
| |
| |
| Where we come from: |
| =================== |
| |
| - start from 8xxrom sources |
| - create PPCBoot project (http://sourceforge.net/projects/ppcboot) |
| - clean up code |
| - make it easier to add custom boards |
| - make it possible to add other [PowerPC] CPUs |
| - extend functions, especially: |
| * Provide extended interface to Linux boot loader |
| * S-Record download |
| * network boot |
| * PCMCIA / CompactFLash / ATA disk / SCSI ... boot |
| - create ARMBoot project (http://sourceforge.net/projects/armboot) |
| - add other CPU families (starting with ARM) |
| - create U-Boot project (http://sourceforge.net/projects/u-boot) |
| |
| |
| Names and Spelling: |
| =================== |
| |
| The "official" name of this project is "Das U-Boot". The spelling |
| "U-Boot" shall be used in all written text (documentation, comments |
| in source files etc.). Example: |
| |
| This is the README file for the U-Boot project. |
| |
| File names etc. shall be based on the string "u-boot". Examples: |
| |
| include/asm-ppc/u-boot.h |
| |
| #include <asm/u-boot.h> |
| |
| Variable names, preprocessor constants etc. shall be either based on |
| the string "u_boot" or on "U_BOOT". Example: |
| |
| U_BOOT_VERSION u_boot_logo |
| IH_OS_U_BOOT u_boot_hush_start |
| |
| |
| Versioning: |
| =========== |
| |
| U-Boot uses a 3 level version number containing a version, a |
| sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2", |
| sub-version "34", and patchlevel "4". |
| |
| The patchlevel is used to indicate certain stages of development |
| between released versions, i. e. officially released versions of |
| U-Boot will always have a patchlevel of "0". |
| |
| |
| Directory Hierarchy: |
| ==================== |
| |
| - board Board dependend files |
| - common Misc architecture independend functions |
| - cpu CPU specific files |
| - disk Code for disk drive partition handling |
| - doc Documentation (don't expect too much) |
| - drivers Common used device drivers |
| - dtt Digital Thermometer and Thermostat drivers |
| - examples Example code for standalone applications, etc. |
| - include Header Files |
| - disk Harddisk interface code |
| - net Networking code |
| - ppc Files generic to PowerPC architecture |
| - post Power On Self Test |
| - post/arch Symlink to architecture specific Power On Self Test |
| - post/arch-ppc PowerPC architecture specific Power On Self Test |
| - post/cpu/mpc8260 MPC8260 CPU specific Power On Self Test |
| - post/cpu/mpc8xx MPC8xx CPU specific Power On Self Test |
| - rtc Real Time Clock drivers |
| - tools Tools to build S-Record or U-Boot images, etc. |
| |
| - cpu/74xx_7xx Files specific to Motorola MPC74xx and 7xx CPUs |
| - cpu/mpc8xx Files specific to Motorola MPC8xx CPUs |
| - cpu/mpc824x Files specific to Motorola MPC824x CPUs |
| - cpu/mpc8260 Files specific to Motorola MPC8260 CPU |
| - cpu/ppc4xx Files specific to IBM 4xx CPUs |
| |
| - board/RPXClassic |
| Files specific to RPXClassic boards |
| - board/RPXlite Files specific to RPXlite boards |
| - board/c2mon Files specific to c2mon boards |
| - board/cogent Files specific to Cogent boards |
| (need further configuration) |
| Files specific to CPCIISER4 boards |
| - board/cpu86 Files specific to CPU86 boards |
| - board/cray/ Files specific to boards manufactured by Cray |
| - board/cray/L1 Files specific to L1 boards |
| - board/cu824 Files specific to CU824 boards |
| - board/ebony Files specific to IBM Ebony board |
| - board/eric Files specific to ERIC boards |
| - board/esd/ Files specific to boards manufactured by ESD |
| - board/esd/adciop Files specific to ADCIOP boards |
| - board/esd/ar405 Files specific to AR405 boards |
| - board/esd/canbt Files specific to CANBT boards |
| - board/esd/cpci405 Files specific to CPCI405 boards |
| - board/esd/cpciiser4 Files specific to CPCIISER4 boards |
| - board/esd/common Common files for ESD boards |
| - board/esd/dasa_sim Files specific to DASA_SIM boards |
| - board/esd/du405 Files specific to DU405 boards |
| - board/esd/ocrtc Files specific to OCRTC boards |
| - board/esd/pci405 Files specific to PCI405 boards |
| - board/esteem192e |
| Files specific to ESTEEM192E boards |
| - board/etx094 Files specific to ETX_094 boards |
| - board/evb64260 |
| Files specific to EVB64260 boards |
| - board/fads Files specific to FADS boards |
| - board/flagadm Files specific to FLAGADM boards |
| - board/gen860t Files specific to GEN860T boards |
| - board/genietv Files specific to GENIETV boards |
| - board/gth Files specific to GTH boards |
| - board/hermes Files specific to HERMES boards |
| - board/hymod Files specific to HYMOD boards |
| - board/icu862 Files specific to ICU862 boards |
| - board/ip860 Files specific to IP860 boards |
| - board/iphase4539 |
| Files specific to Interphase4539 boards |
| - board/ivm Files specific to IVMS8/IVML24 boards |
| - board/lantec Files specific to LANTEC boards |
| - board/lwmon Files specific to LWMON boards |
| - board/mbx8xx Files specific to MBX boards |
| - board/mpc8260ads |
| Files specific to MMPC8260ADS boards |
| - board/mpl/ Files specific to boards manufactured by MPL |
| - board/mpl/common Common files for MPL boards |
| - board/mpl/pip405 Files specific to PIP405 boards |
| - board/mpl/mip405 Files specific to MIP405 boards |
| - board/musenki Files specific to MUSEKNI boards |
| - board/mvs1 Files specific to MVS1 boards |
| - board/nx823 Files specific to NX823 boards |
| - board/oxc Files specific to OXC boards |
| - board/pcippc2 Files specific to PCIPPC2/PCIPPC6 boards |
| - board/pm826 Files specific to PM826 boards |
| - board/ppmc8260 |
| Files specific to PPMC8260 boards |
| - board/rpxsuper |
| Files specific to RPXsuper boards |
| - board/rsdproto |
| Files specific to RSDproto boards |
| - board/sandpoint |
| Files specific to Sandpoint boards |
| - board/sbc8260 Files specific to SBC8260 boards |
| - board/sacsng Files specific to SACSng boards |
| - board/siemens Files specific to boards manufactured by Siemens AG |
| - board/siemens/CCM Files specific to CCM boards |
| - board/siemens/IAD210 Files specific to IAD210 boards |
| - board/siemens/SCM Files specific to SCM boards |
| - board/siemens/pcu_e Files specific to PCU_E boards |
| - board/sixnet Files specific to SIXNET boards |
| - board/spd8xx Files specific to SPD8xxTS boards |
| - board/tqm8260 Files specific to TQM8260 boards |
| - board/tqm8xx Files specific to TQM8xxL boards |
| - board/w7o Files specific to W7O boards |
| - board/walnut405 |
| Files specific to Walnut405 boards |
| - board/westel/ Files specific to boards manufactured by Westel Wireless |
| - board/westel/amx860 Files specific to AMX860 boards |
| - board/utx8245 Files specific to UTX8245 boards |
| |
| Software Configuration: |
| ======================= |
| |
| Configuration is usually done using C preprocessor defines; the |
| rationale behind that is to avoid dead code whenever possible. |
| |
| There are two classes of configuration variables: |
| |
| * Configuration _OPTIONS_: |
| These are selectable by the user and have names beginning with |
| "CONFIG_". |
| |
| * Configuration _SETTINGS_: |
| These depend on the hardware etc. and should not be meddled with if |
| you don't know what you're doing; they have names beginning with |
| "CFG_". |
| |
| Later we will add a configuration tool - probably similar to or even |
| identical to what's used for the Linux kernel. Right now, we have to |
| do the configuration by hand, which means creating some symbolic |
| links and editing some configuration files. We use the TQM8xxL boards |
| as an example here. |
| |
| |
| Selection of Processor Architecture and Board Type: |
| --------------------------------------------------- |
| |
| For all supported boards there are ready-to-use default |
| configurations available; just type "make <board_name>_config". |
| |
| Example: For a TQM823L module type: |
| |
| cd u-boot |
| make TQM823L_config |
| |
| For the Cogent platform, you need to specify the cpu type as well; |
| e.g. "make cogent_mpc8xx_config". And also configure the cogent |
| directory according to the instructions in cogent/README. |
| |
| |
| Configuration Options: |
| ---------------------- |
| |
| Configuration depends on the combination of board and CPU type; all |
| such information is kept in a configuration file |
| "include/configs/<board_name>.h". |
| |
| Example: For a TQM823L module, all configuration settings are in |
| "include/configs/TQM823L.h". |
| |
| |
| Many of the options are named exactly as the corresponding Linux |
| kernel configuration options. The intention is to make it easier to |
| build a config tool - later. |
| |
| |
| The following options need to be configured: |
| |
| - CPU Type: Define exactly one of |
| |
| PowerPC based CPUs: |
| ------------------- |
| CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860 |
| or CONFIG_MPC824X, CONFIG_MPC8260 |
| or CONFIG_IOP480 |
| or CONFIG_405GP |
| or CONFIG_440 |
| or CONFIG_MPC74xx |
| |
| ARM based CPUs: |
| --------------- |
| CONFIG_SA1110 |
| CONFIG_ARM7 |
| CONFIG_PXA250 |
| |
| |
| - Board Type: Define exactly one of |
| |
| PowerPC based boards: |
| --------------------- |
| |
| CONFIG_ADCIOP, CONFIG_ICU862 CONFIG_RPXsuper, |
| CONFIG_ADS860, CONFIG_IP860, CONFIG_SM850, |
| CONFIG_AMX860, CONFIG_IPHASE4539, CONFIG_SPD823TS, |
| CONFIG_AR405, CONFIG_IVML24, CONFIG_SXNI855T, |
| CONFIG_BAB7xx, CONFIG_IVML24_128, CONFIG_Sandpoint8240, |
| CONFIG_CANBT, CONFIG_IVML24_256, CONFIG_Sandpoint8245, |
| CONFIG_CCM, CONFIG_IVMS8, CONFIG_TQM823L, |
| CONFIG_CPCI405, CONFIG_IVMS8_128, CONFIG_TQM850L, |
| CONFIG_CPCI4052, CONFIG_IVMS8_256, CONFIG_TQM855L, |
| CONFIG_CPCIISER4, CONFIG_LANTEC, CONFIG_TQM860L, |
| CONFIG_CPU86, CONFIG_MBX, CONFIG_TQM8260, |
| CONFIG_CRAYL1, CONFIG_MBX860T, CONFIG_TTTech, |
| CONFIG_CU824, CONFIG_MHPC, CONFIG_UTX8245, |
| CONFIG_DASA_SIM, CONFIG_MIP405, CONFIG_W7OLMC, |
| CONFIG_DU405, CONFIG_MOUSSE, CONFIG_W7OLMG, |
| CONFIG_ELPPC, CONFIG_MPC8260ADS, CONFIG_WALNUT405, |
| CONFIG_ERIC, CONFIG_MUSENKI, CONFIG_ZUMA, |
| CONFIG_ESTEEM192E, CONFIG_MVS1, CONFIG_c2mon, |
| CONFIG_ETX094, CONFIG_NX823, CONFIG_cogent_mpc8260, |
| CONFIG_EVB64260, CONFIG_OCRTC, CONFIG_cogent_mpc8xx, |
| CONFIG_FADS823, CONFIG_ORSG, CONFIG_ep8260, |
| CONFIG_FADS850SAR, CONFIG_OXC, CONFIG_gw8260, |
| CONFIG_FADS860T, CONFIG_PCI405, CONFIG_hermes, |
| CONFIG_FLAGADM, CONFIG_PCIPPC2, CONFIG_hymod, |
| CONFIG_FPS850L, CONFIG_PCIPPC6, CONFIG_lwmon, |
| CONFIG_GEN860T, CONFIG_PIP405, CONFIG_pcu_e, |
| CONFIG_GENIETV, CONFIG_PM826, CONFIG_ppmc8260, |
| CONFIG_GTH, CONFIG_RPXClassic, CONFIG_rsdproto, |
| CONFIG_IAD210, CONFIG_RPXlite, CONFIG_sbc8260, |
| CONFIG_EBONY, CONFIG_sacsng, CONFIG_FPS860L, |
| CONFIG_V37 |
| |
| ARM based boards: |
| ----------------- |
| |
| CONFIG_HHP_CRADLE, CONFIG_DNP1110, CONFIG_EP7312, |
| CONFIG_IMPA7, CONFIG_LART, CONFIG_LUBBOCK, |
| CONFIG_SHANNON, CONFIG_SMDK2400, CONFIG_SMDK2410, |
| CONFIG_TRAB |
| |
| |
| - CPU Module Type: (if CONFIG_COGENT is defined) |
| Define exactly one of |
| CONFIG_CMA286_60_OLD |
| --- FIXME --- not tested yet: |
| CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, |
| CONFIG_CMA287_23, CONFIG_CMA287_50 |
| |
| - Motherboard Type: (if CONFIG_COGENT is defined) |
| Define exactly one of |
| CONFIG_CMA101, CONFIG_CMA102 |
| |
| - Motherboard I/O Modules: (if CONFIG_COGENT is defined) |
| Define one or more of |
| CONFIG_CMA302 |
| |
| - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) |
| Define one or more of |
| CONFIG_LCD_HEARTBEAT - update a character position on |
| the lcd display every second with |
| a "rotator" |\-/|\-/ |
| |
| - MPC824X Family Member (if CONFIG_MPC824X is defined) |
| Define exactly one of |
| CONFIG_MPC8240, CONFIG_MPC8245 |
| |
| - 8xx CPU Options: (if using an 8xx cpu) |
| Define one or more of |
| CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() can not work e.g. |
| no 32KHz reference PIT/RTC clock |
| |
| - Clock Interface: |
| CONFIG_CLOCKS_IN_MHZ |
| |
| U-Boot stores all clock information in Hz |
| internally. For binary compatibility with older Linux |
| kernels (which expect the clocks passed in the |
| bd_info data to be in MHz) the environment variable |
| "clocks_in_mhz" can be defined so that U-Boot |
| converts clock data to MHZ before passing it to the |
| Linux kernel. |
| |
| When CONFIG_CLOCKS_IN_MHZ is defined, a definition of |
| "clocks_in_mhz=1" is automatically included in the |
| default environment. |
| |
| - Console Interface: |
| Depending on board, define exactly one serial port |
| (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, |
| CONFIG_8xx_CONS_SCC1, ...), or switch off the serial |
| console by defining CONFIG_8xx_CONS_NONE |
| |
| Note: if CONFIG_8xx_CONS_NONE is defined, the serial |
| port routines must be defined elsewhere |
| (i.e. serial_init(), serial_getc(), ...) |
| |
| CONFIG_CFB_CONSOLE |
| Enables console device for a color framebuffer. Needs following |
| defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) |
| VIDEO_FB_LITTLE_ENDIAN graphic memory organisation |
| (default big endian) |
| VIDEO_HW_RECTFILL graphic chip supports |
| rectangle fill |
| (cf. smiLynxEM) |
| VIDEO_HW_BITBLT graphic chip supports |
| bit-blit (cf. smiLynxEM) |
| VIDEO_VISIBLE_COLS visible pixel columns |
| (cols=pitch) |
| VIDEO_VISIBLE_ROWS visible pixel rows |
| VIDEO_PIXEL_SIZE bytes per pixel |
| VIDEO_DATA_FORMAT graphic data format |
| (0-5, cf. cfb_console.c) |
| VIDEO_FB_ADRS framebuffer address |
| VIDEO_KBD_INIT_FCT keyboard int fct |
| (i.e. i8042_kbd_init()) |
| VIDEO_TSTC_FCT test char fct |
| (i.e. i8042_tstc) |
| VIDEO_GETC_FCT get char fct |
| (i.e. i8042_getc) |
| CONFIG_CONSOLE_CURSOR cursor drawing on/off |
| (requires blink timer |
| cf. i8042.c) |
| CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) |
| CONFIG_CONSOLE_TIME display time/date info in |
| upper right corner |
| (requires CFG_CMD_DATE) |
| CONFIG_VIDEO_LOGO display Linux logo in |
| upper left corner |
| CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of |
| linux_logo.h for logo. |
| Requires CONFIG_VIDEO_LOGO |
| CONFIG_CONSOLE_EXTRA_INFO |
| addional board info beside |
| the logo |
| |
| When CONFIG_CFB_CONSOLE is defined, video console is |
| default i/o. Serial console can be forced with |
| environment 'console=serial'. |
| |
| - Console Baudrate: |
| CONFIG_BAUDRATE - in bps |
| Select one of the baudrates listed in |
| CFG_BAUDRATE_TABLE, see below. |
| |
| - Interrupt driven serial port input: |
| CONFIG_SERIAL_SOFTWARE_FIFO |
| |
| PPC405GP only. |
| Use an interrupt handler for receiving data on the |
| serial port. It also enables using hardware handshake |
| (RTS/CTS) and UART's built-in FIFO. Set the number of |
| bytes the interrupt driven input buffer should have. |
| |
| Set to 0 to disable this feature (this is the default). |
| This will also disable hardware handshake. |
| |
| - Boot Delay: CONFIG_BOOTDELAY - in seconds |
| Delay before automatically booting the default image; |
| set to -1 to disable autoboot. |
| |
| See doc/README.autoboot for these options that |
| work with CONFIG_BOOTDELAY. None are required. |
| CONFIG_BOOT_RETRY_TIME |
| CONFIG_BOOT_RETRY_MIN |
| CONFIG_AUTOBOOT_KEYED |
| CONFIG_AUTOBOOT_PROMPT |
| CONFIG_AUTOBOOT_DELAY_STR |
| CONFIG_AUTOBOOT_STOP_STR |
| CONFIG_AUTOBOOT_DELAY_STR2 |
| CONFIG_AUTOBOOT_STOP_STR2 |
| CONFIG_ZERO_BOOTDELAY_CHECK |
| CONFIG_RESET_TO_RETRY |
| |
| - Autoboot Command: |
| CONFIG_BOOTCOMMAND |
| Only needed when CONFIG_BOOTDELAY is enabled; |
| define a command string that is automatically executed |
| when no character is read on the console interface |
| within "Boot Delay" after reset. |
| |
| CONFIG_BOOTARGS |
| This can be used to pass arguments to the bootm |
| command. The value of CONFIG_BOOTARGS goes into the |
| environment value "bootargs". |
| |
| CONFIG_RAMBOOT and CONFIG_NFSBOOT |
| The value of these goes into the environment as |
| "ramboot" and "nfsboot" respectively, and can be used |
| as a convenience, when switching between booting from |
| ram and nfs. |
| |
| - Pre-Boot Commands: |
| CONFIG_PREBOOT |
| |
| When this option is #defined, the existence of the |
| environment variable "preboot" will be checked |
| immediately before starting the CONFIG_BOOTDELAY |
| countdown and/or running the auto-boot command resp. |
| entering interactive mode. |
| |
| This feature is especially useful when "preboot" is |
| automatically generated or modified. For an example |
| see the LWMON board specific code: here "preboot" is |
| modified when the user holds down a certain |
| combination of keys on the (special) keyboard when |
| booting the systems |
| |
| - Serial Download Echo Mode: |
| CONFIG_LOADS_ECHO |
| If defined to 1, all characters received during a |
| serial download (using the "loads" command) are |
| echoed back. This might be needed by some terminal |
| emulations (like "cu"), but may as well just take |
| time on others. This setting #define's the initial |
| value of the "loads_echo" environment variable. |
| |
| - Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined) |
| CONFIG_KGDB_BAUDRATE |
| Select one of the baudrates listed in |
| CFG_BAUDRATE_TABLE, see below. |
| |
| - Monitor Functions: |
| CONFIG_COMMANDS |
| Most monitor functions can be selected (or |
| de-selected) by adjusting the definition of |
| CONFIG_COMMANDS; to select individual functions, |
| #define CONFIG_COMMANDS by "OR"ing any of the |
| following values: |
| |
| #define enables commands: |
| ------------------------- |
| CFG_CMD_ASKENV * ask for env variable |
| CFG_CMD_BDI bdinfo |
| CFG_CMD_BEDBUG Include BedBug Debugger |
| CFG_CMD_BOOTD bootd |
| CFG_CMD_CACHE icache, dcache |
| CFG_CMD_CONSOLE coninfo |
| CFG_CMD_DATE * support for RTC, date/time... |
| CFG_CMD_DHCP DHCP support |
| CFG_CMD_ECHO * echo arguments |
| CFG_CMD_EEPROM * EEPROM read/write support |
| CFG_CMD_ELF bootelf, bootvx |
| CFG_CMD_ENV saveenv |
| CFG_CMD_FDC * Floppy Disk Support |
| CFG_CMD_FDOS * Dos diskette Support |
| CFG_CMD_FLASH flinfo, erase, protect |
| CFG_CMD_FPGA FPGA device initialization support |
| CFG_CMD_I2C * I2C serial bus support |
| CFG_CMD_IDE * IDE harddisk support |
| CFG_CMD_IMI iminfo |
| CFG_CMD_IMMAP * IMMR dump support |
| CFG_CMD_IRQ * irqinfo |
| CFG_CMD_KGDB * kgdb |
| CFG_CMD_LOADB loadb |
| CFG_CMD_LOADS loads |
| CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, |
| loop, mtest |
| CFG_CMD_MII MII utility commands |
| CFG_CMD_NET bootp, tftpboot, rarpboot |
| CFG_CMD_PCI * pciinfo |
| CFG_CMD_PCMCIA * PCMCIA support |
| CFG_CMD_REGINFO * Register dump |
| CFG_CMD_RUN run command in env variable |
| CFG_CMD_SCSI * SCSI Support |
| CFG_CMD_SETGETDCR Support for DCR Register access (4xx only) |
| CFG_CMD_SPI * SPI serial bus support |
| CFG_CMD_USB * USB support |
| CFG_CMD_BSP * Board SPecific functions |
| ----------------------------------------------- |
| CFG_CMD_ALL all |
| |
| CFG_CMD_DFL Default configuration; at the moment |
| this is includes all commands, except |
| the ones marked with "*" in the list |
| above. |
| |
| If you don't define CONFIG_COMMANDS it defaults to |
| CFG_CMD_DFL in include/cmd_confdefs.h. A board can |
| override the default settings in the respective |
| include file. |
| |
| EXAMPLE: If you want all functions except of network |
| support you can write: |
| |
| #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET) |
| |
| |
| Note: Don't enable the "icache" and "dcache" commands |
| (configuration option CFG_CMD_CACHE) unless you know |
| what you (and your U-Boot users) are doing. Data |
| cache cannot be enabled on systems like the 8xx or |
| 8260 (where accesses to the IMMR region must be |
| uncached), and it cannot be disabled on all other |
| systems where we (mis-) use the data cache to hold an |
| initial stack and some data. |
| |
| |
| XXX - this list needs to get updated! |
| |
| - Watchdog: |
| CONFIG_WATCHDOG |
| If this variable is defined, it enables watchdog |
| support. There must support in the platform specific |
| code for a watchdog. For the 8xx and 8260 CPUs, the |
| SIU Watchdog feature is enabled in the SYPCR |
| register. |
| |
| - Real-Time Clock: |
| |
| When CFG_CMD_DATE is selected, the type of the RTC |
| has to be selected, too. Define exactly one of the |
| following options: |
| |
| CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx |
| CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC |
| CONFIG_RTC_MC146818 - use MC146818 RTC |
| CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC |
| |
| - Timestamp Support: |
| |
| When CONFIG_TIMESTAMP is selected, the timestamp |
| (date and time) of an image is printed by image |
| commands like bootm or iminfo. This option is |
| automatically enabled when you select CFG_CMD_DATE . |
| |
| - Partition Support: |
| CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION |
| and/or CONFIG_ISO_PARTITION |
| |
| If IDE or SCSI support is enabled (CFG_CMD_IDE or |
| CFG_CMD_SCSI) you must configure support for at least |
| one partition type as well. |
| |
| - IDE Reset method: |
| CONFIG_IDE_RESET_ROUTINE |
| |
| Set this to define that instead of a reset Pin, the |
| routine ide_set_reset(int idereset) will be used. |
| |
| - ATAPI Support: |
| CONFIG_ATAPI |
| |
| Set this to enable ATAPI support. |
| |
| - SCSI Support: |
| At the moment only there is only support for the |
| SYM53C8XX SCSI controller; define |
| CONFIG_SCSI_SYM53C8XX to enable it. |
| |
| CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and |
| CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * |
| CFG_SCSI_MAX_LUN] can be adjusted to define the |
| maximum numbers of LUNs, SCSI ID's and target |
| devices. |
| CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) |
| |
| - NETWORK Support (PCI): |
| CONFIG_EEPRO100 |
| Support for Intel 82557/82559/82559ER chips. |
| Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom |
| write routine for first time initialisation. |
| |
| CONFIG_TULIP |
| Support for Digital 2114x chips. |
| Optional CONFIG_TULIP_SELECT_MEDIA for board specific |
| modem chip initialisation (KS8761/QS6611). |
| |
| CONFIG_NATSEMI |
| Support for National dp83815 chips. |
| |
| CONFIG_NS8382X |
| Support for National dp8382[01] gigabit chips. |
| |
| - USB Support: |
| At the moment only the UHCI host controller is |
| supported (PIP405, MIP405); define |
| CONFIG_USB_UHCI to enable it. |
| define CONFIG_USB_KEYBOARD to enable the USB Keyboard |
| end define CONFIG_USB_STORAGE to enable the USB |
| storage devices. |
| Note: |
| Supported are USB Keyboards and USB Floppy drives |
| (TEAC FD-05PUB). |
| |
| - Keyboard Support: |
| CONFIG_ISA_KEYBOARD |
| |
| Define this to enable standard (PC-Style) keyboard |
| support |
| |
| CONFIG_I8042_KBD |
| Standard PC keyboard driver with US (is default) and |
| GERMAN key layout (switch via environment 'keymap=de') support. |
| Export function i8042_kbd_init, i8042_tstc and i8042_getc |
| for cfb_console. Supports cursor blinking. |
| |
| - Video support: |
| CONFIG_VIDEO |
| |
| Define this to enable video support (for output to |
| video). |
| |
| CONFIG_VIDEO_CT69000 |
| |
| Enable Chips & Technologies 69000 Video chip |
| |
| CONFIG_VIDEO_SMI_LYNXEM |
| Enable Silicon Motion SMI 712/710/810 Video chip |
| Videomode are selected via environment 'videomode' with |
| standard LiLo mode numbers. |
| Following modes are supported (* is default): |
| |
| 800x600 1024x768 1280x1024 |
| 256 (8bit) 303* 305 307 |
| 65536 (16bit) 314 317 31a |
| 16,7 Mill (24bit) 315 318 31b |
| (i.e. setenv videomode 317; saveenv; reset;) |
| |
| CONFIG_VIDEO_SED13806 |
| Enable Epson SED13806 driver. This driver supports 8bpp |
| and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP |
| or CONFIG_VIDEO_SED13806_16BPP |
| |
| |
| - LCD Support: CONFIG_LCD |
| |
| Define this to enable LCD support (for output to LCD |
| display); also select one of the supported displays |
| by defining one of these: |
| |
| CONFIG_NEC_NL6648AC33: |
| |
| NEC NL6648AC33-18. Active, color, single scan. |
| |
| CONFIG_NEC_NL6648BC20 |
| |
| NEC NL6648BC20-08. 6.5", 640x480. |
| Active, color, single scan. |
| |
| CONFIG_SHARP_16x9 |
| |
| Sharp 320x240. Active, color, single scan. |
| It isn't 16x9, and I am not sure what it is. |
| |
| CONFIG_SHARP_LQ64D341 |
| |
| Sharp LQ64D341 display, 640x480. |
| Active, color, single scan. |
| |
| CONFIG_HLD1045 |
| |
| HLD1045 display, 640x480. |
| Active, color, single scan. |
| |
| CONFIG_OPTREX_BW |
| |
| Optrex CBL50840-2 NF-FW 99 22 M5 |
| or |
| Hitachi LMG6912RPFC-00T |
| or |
| Hitachi SP14Q002 |
| |
| 320x240. Black & white. |
| |
| Normally display is black on white background; define |
| CFG_WHITE_ON_BLACK to get it inverted. |
| |
| - Ethernet address: |
| CONFIG_ETHADDR |
| CONFIG_ETH2ADDR |
| CONFIG_ETH3ADDR |
| |
| Define a default value for ethernet address to use |
| for the respective ethernet interface, in case this |
| is not determined automatically. |
| |
| - IP address: |
| CONFIG_IPADDR |
| |
| Define a default value for the IP address to use for |
| the default ethernet interface, in case this is not |
| determined through e.g. bootp. |
| |
| - Server IP address: |
| CONFIG_SERVERIP |
| |
| Defines a default value for theIP address of a TFTP |
| server to contact when using the "tftboot" command. |
| |
| - BOOTP Recovery Mode: |
| CONFIG_BOOTP_RANDOM_DELAY |
| |
| If you have many targets in a network that try to |
| boot using BOOTP, you may want to avoid that all |
| systems send out BOOTP requests at precisely the same |
| moment (which would happen for instance at recovery |
| from a power failure, when all systems will try to |
| boot, thus flooding the BOOTP server. Defining |
| CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be |
| inserted before sending out BOOTP requests. The |
| following delays are insterted then: |
| |
| 1st BOOTP request: delay 0 ... 1 sec |
| 2nd BOOTP request: delay 0 ... 2 sec |
| 3rd BOOTP request: delay 0 ... 4 sec |
| 4th and following |
| BOOTP requests: delay 0 ... 8 sec |
| |
| - Status LED: CONFIG_STATUS_LED |
| |
| Several configurations allow to display the current |
| status using a LED. For instance, the LED will blink |
| fast while running U-Boot code, stop blinking as |
| soon as a reply to a BOOTP request was received, and |
| start blinking slow once the Linux kernel is running |
| (supported by a status LED driver in the Linux |
| kernel). Defining CONFIG_STATUS_LED enables this |
| feature in U-Boot. |
| |
| - CAN Support: CONFIG_CAN_DRIVER |
| |
| Defining CONFIG_CAN_DRIVER enables CAN driver support |
| on those systems that support this (optional) |
| feature, like the TQM8xxL modules. |
| |
| - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C |
| |
| Enables I2C serial bus commands. If this is selected, |
| either CONFIG_HARD_I2C or CONFIG_SOFT_I2C must be defined |
| to include the appropriate I2C driver. |
| |
| See also: common/cmd_i2c.c for a description of the |
| command line interface. |
| |
| |
| CONFIG_HARD_I2C |
| |
| Selects the CPM hardware driver for I2C. |
| |
| CONFIG_SOFT_I2C |
| |
| Use software (aka bit-banging) driver instead of CPM |
| or similar hardware support for I2C. This is configured |
| via the following defines. |
| |
| I2C_INIT |
| |
| (Optional). Any commands necessary to enable I2C |
| controller or configure ports. |
| |
| I2C_PORT |
| |
| (Only for MPC8260 CPU). The I/O port to use (the code |
| assumes both bits are on the same port). Valid values |
| are 0..3 for ports A..D. |
| |
| I2C_ACTIVE |
| |
| The code necessary to make the I2C data line active |
| (driven). If the data line is open collector, this |
| define can be null. |
| |
| I2C_TRISTATE |
| |
| The code necessary to make the I2C data line tri-stated |
| (inactive). If the data line is open collector, this |
| define can be null. |
| |
| I2C_READ |
| |
| Code that returns TRUE if the I2C data line is high, |
| FALSE if it is low. |
| |
| I2C_SDA(bit) |
| |
| If <bit> is TRUE, sets the I2C data line high. If it |
| is FALSE, it clears it (low). |
| |
| I2C_SCL(bit) |
| |
| If <bit> is TRUE, sets the I2C clock line high. If it |
| is FALSE, it clears it (low). |
| |
| I2C_DELAY |
| |
| This delay is invoked four times per clock cycle so this |
| controls the rate of data transfer. The data rate thus |
| is 1 / (I2C_DELAY * 4). |
| |
| CFG_I2C_INIT_BOARD |
| |
| When a board is reset during an i2c bus transfer |
| chips might think that the current transfer is still |
| in progress. On some boards it is possible to access |
| the i2c SCLK line directly, either by using the |
| processor pin as a GPIO or by having a second pin |
| connected to the bus. If this option is defined a |
| custom i2c_init_board() routine in boards/xxx/board.c |
| is run early in the boot sequence. |
| |
| - SPI Support: CONFIG_SPI |
| |
| Enables SPI driver (so far only tested with |
| SPI EEPROM, also an instance works with Crystal A/D and |
| D/As on the SACSng board) |
| |
| CONFIG_SPI_X |
| |
| Enables extended (16-bit) SPI EEPROM addressing. |
| (symmetrical to CONFIG_I2C_X) |
| |
| CONFIG_SOFT_SPI |
| |
| Enables a software (bit-bang) SPI driver rather than |
| using hardware support. This is a general purpose |
| driver that only requires three general I/O port pins |
| (two outputs, one input) to function. If this is |
| defined, the board configuration must define several |
| SPI configuration items (port pins to use, etc). For |
| an example, see include/configs/sacsng.h. |
| |
| - FPGA Support: CONFIG_FPGA_COUNT |
| |
| Specify the number of FPGA devices to support. |
| |
| CONFIG_FPGA |
| |
| Used to specify the types of FPGA devices. For |
| example, |
| #define CONFIG_FPGA CFG_XILINX_VIRTEX2 |
| |
| CFG_FPGA_PROG_FEEDBACK |
| |
| Enable printing of hash marks during FPGA |
| configuration. |
| |
| CFG_FPGA_CHECK_BUSY |
| |
| Enable checks on FPGA configuration interface busy |
| status by the configuration function. This option |
| will require a board or device specific function to |
| be written. |
| |
| CONFIG_FPGA_DELAY |
| |
| If defined, a function that provides delays in the |
| FPGA configuration driver. |
| |
| CFG_FPGA_CHECK_CTRLC |
| |
| Allow Control-C to interrupt FPGA configuration |
| |
| CFG_FPGA_CHECK_ERROR |
| |
| Check for configuration errors during FPGA bitfile |
| loading. For example, abort during Virtex II |
| configuration if the INIT_B line goes low (which |
| indicated a CRC error). |
| |
| CFG_FPGA_WAIT_INIT |
| |
| Maximum time to wait for the INIT_B line to deassert |
| after PROB_B has been deasserted during a Virtex II |
| FPGA configuration sequence. The default time is 500 mS. |
| |
| CFG_FPGA_WAIT_BUSY |
| |
| Maximum time to wait for BUSY to deassert during |
| Virtex II FPGA configuration. The default is 5 mS. |
| |
| CFG_FPGA_WAIT_CONFIG |
| |
| Time to wait after FPGA configuration. The default is |
| 200 mS. |
| |
| - FPGA Support: CONFIG_FPGA_COUNT |
| |
| Specify the number of FPGA devices to support. |
| |
| CONFIG_FPGA |
| |
| Used to specify the types of FPGA devices. For example, |
| #define CONFIG_FPGA CFG_XILINX_VIRTEX2 |
| |
| CFG_FPGA_PROG_FEEDBACK |
| |
| Enable printing of hash marks during FPGA configuration. |
| |
| CFG_FPGA_CHECK_BUSY |
| |
| Enable checks on FPGA configuration interface busy |
| status by the configuration function. This option |
| will require a board or device specific function to |
| be written. |
| |
| CONFIG_FPGA_DELAY |
| |
| If defined, a function that provides delays in the FPGA |
| configuration driver. |
| |
| CFG_FPGA_CHECK_CTRLC |
| Allow Control-C to interrupt FPGA configuration |
| |
| CFG_FPGA_CHECK_ERROR |
| |
| Check for configuration errors during FPGA bitfile |
| loading. For example, abort during Virtex II |
| configuration if the INIT_B line goes low (which |
| indicated a CRC error). |
| |
| CFG_FPGA_WAIT_INIT |
| |
| Maximum time to wait for the INIT_B line to deassert |
| after PROB_B has been deasserted during a Virtex II |
| FPGA configuration sequence. The default time is 500 |
| mS. |
| |
| CFG_FPGA_WAIT_BUSY |
| |
| Maximum time to wait for BUSY to deassert during |
| Virtex II FPGA configuration. The default is 5 mS. |
| |
| CFG_FPGA_WAIT_CONFIG |
| |
| Time to wait after FPGA configuration. The default is |
| 200 mS. |
| |
| - Configuration Management: |
| CONFIG_IDENT_STRING |
| |
| If defined, this string will be added to the U-Boot |
| version information (U_BOOT_VERSION) |
| |
| - Vendor Parameter Protection: |
| |
| U-Boot considers the values of the environment |
| variables "serial#" (Board Serial Number) and |
| "ethaddr" (Ethernet Address) to bb parameters that |
| are set once by the board vendor / manufacturer, and |
| protects these variables from casual modification by |
| the user. Once set, these variables are read-only, |
| and write or delete attempts are rejected. You can |
| change this behviour: |
| |
| If CONFIG_ENV_OVERWRITE is #defined in your config |
| file, the write protection for vendor parameters is |
| completely disabled. Anybody can change or delete |
| these parameters. |
| |
| Alternatively, if you #define _both_ CONFIG_ETHADDR |
| _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default |
| ethernet address is installed in the environment, |
| which can be changed exactly ONCE by the user. [The |
| serial# is unaffected by this, i. e. it remains |
| read-only.] |
| |
| - Protected RAM: |
| CONFIG_PRAM |
| |
| Define this variable to enable the reservation of |
| "protected RAM", i. e. RAM which is not overwritten |
| by U-Boot. Define CONFIG_PRAM to hold the number of |
| kB you want to reserve for pRAM. You can overwrite |
| this default value by defining an environment |
| variable "pram" to the number of kB you want to |
| reserve. Note that the board info structure will |
| still show the full amount of RAM. If pRAM is |
| reserved, a new environment variable "mem" will |
| automatically be defined to hold the amount of |
| remaining RAM in a form that can be passed as boot |
| argument to Linux, for instance like that: |
| |
| setenv bootargs ... mem=\$(mem) |
| saveenv |
| |
| This way you can tell Linux not to use this memory, |
| either, which results in a memory region that will |
| not be affected by reboots. |
| |
| *WARNING* If your board configuration uses automatic |
| detection of the RAM size, you must make sure that |
| this memory test is non-destructive. So far, the |
| following board configurations are known to be |
| "pRAM-clean": |
| |
| ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, |
| HERMES, IP860, RPXlite, LWMON, LANTEC, |
| PCU_E, FLAGADM, TQM8260 |
| |
| - Error Recovery: |
| CONFIG_PANIC_HANG |
| |
| Define this variable to stop the system in case of a |
| fatal error, so that you have to reset it manually. |
| This is probably NOT a good idea for an embedded |
| system where you want to system to reboot |
| automatically as fast as possible, but it may be |
| useful during development since you can try to debug |
| the conditions that lead to the situation. |
| |
| CONFIG_NET_RETRY_COUNT |
| |
| This variable defines the number of retries for |
| network operations like ARP, RARP, TFTP, or BOOTP |
| before giving up the operation. If not defined, a |
| default value of 5 is used. |
| |
| - Command Interpreter: |
| CFG_HUSH_PARSER |
| |
| Define this variable to enable the "hush" shell (from |
| Busybox) as command line interpreter, thus enabling |
| powerful command line syntax like |
| if...then...else...fi conditionals or `&&' and '||' |
| constructs ("shell scripts"). |
| |
| If undefined, you get the old, much simpler behaviour |
| with a somewhat smaller memory footprint. |
| |
| |
| CFG_PROMPT_HUSH_PS2 |
| |
| This defines the secondary prompt string, which is |
| printed when the command interpreter needs more input |
| to complete a command. Usually "> ". |
| |
| Note: |
| |
| In the current implementation, the local variables |
| space and global environment variables space are |
| separated. Local variables are those you define by |
| simply typing like `name=value'. To access a local |
| variable later on, you have write `$name' or |
| `${name}'; variable directly by typing say `$name' at |
| the command prompt. |
| |
| Global environment variables are those you use |
| setenv/printenv to work with. To run a command stored |
| in such a variable, you need to use the run command, |
| and you must not use the '$' sign to access them. |
| |
| To store commands and special characters in a |
| variable, please use double quotation marks |
| surrounding the whole text of the variable, instead |
| of the backslashes before semicolons and special |
| symbols. |
| |
| - Default Environment |
| CONFIG_EXTRA_ENV_SETTINGS |
| |
| Define this to contain any number of null terminated |
| strings (variable = value pairs) that will be part of |
| the default enviroment compiled into the boot image. |
| |
| For example, place something like this in your |
| board's config file: |
| |
| #define CONFIG_EXTRA_ENV_SETTINGS \ |
| "myvar1=value1\0" \ |
| "myvar2=value2\0" |
| |
| Warning: This method is based on knowledge about the |
| internal format how the environment is stored by the |
| U-Boot code. This is NOT an official, exported |
| interface! Although it is unlikely that this format |
| will change soon, but there is no guarantee either. |
| You better know what you are doing here. |
| |
| Note: overly (ab)use of the default environment is |
| discouraged. Make sure to check other ways to preset |
| the environment like the autoscript function or the |
| boot command first. |
| |
| - Show boot progress |
| CONFIG_SHOW_BOOT_PROGRESS |
| |
| Defining this option allows to add some board- |
| specific code (calling a user-provided function |
| "show_boot_progress(int)") that enables you to show |
| the system's boot progress on some display (for |
| example, some LED's) on your board. At the moment, |
| the following checkpoints are implemented: |
| |
| Arg Where When |
| 1 common/cmd_bootm.c before attempting to boot an image |
| -1 common/cmd_bootm.c Image header has bad magic number |
| 2 common/cmd_bootm.c Image header has correct magic number |
| -2 common/cmd_bootm.c Image header has bad checksum |
| 3 common/cmd_bootm.c Image header has correct checksum |
| -3 common/cmd_bootm.c Image data has bad checksum |
| 4 common/cmd_bootm.c Image data has correct checksum |
| -4 common/cmd_bootm.c Image is for unsupported architecture |
| 5 common/cmd_bootm.c Architecture check OK |
| -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) |
| 6 common/cmd_bootm.c Image Type check OK |
| -6 common/cmd_bootm.c gunzip uncompression error |
| -7 common/cmd_bootm.c Unimplemented compression type |
| 7 common/cmd_bootm.c Uncompression OK |
| -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) |
| 8 common/cmd_bootm.c Image Type check OK |
| -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) |
| 9 common/cmd_bootm.c Start initial ramdisk verification |
| -10 common/cmd_bootm.c Ramdisk header has bad magic number |
| -11 common/cmd_bootm.c Ramdisk header has bad checksum |
| 10 common/cmd_bootm.c Ramdisk header is OK |
| -12 common/cmd_bootm.c Ramdisk data has bad checksum |
| 11 common/cmd_bootm.c Ramdisk data has correct checksum |
| 12 common/cmd_bootm.c Ramdisk verification complete, start loading |
| -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk) |
| 13 common/cmd_bootm.c Start multifile image verification |
| 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue. |
| 15 common/cmd_bootm.c All preparation done, transferring control to OS |
| |
| -1 common/cmd_doc.c Bad usage of "doc" command |
| -1 common/cmd_doc.c No boot device |
| -1 common/cmd_doc.c Unknown Chip ID on boot device |
| -1 common/cmd_doc.c Read Error on boot device |
| -1 common/cmd_doc.c Image header has bad magic number |
| |
| -1 common/cmd_ide.c Bad usage of "ide" command |
| -1 common/cmd_ide.c No boot device |
| -1 common/cmd_ide.c Unknown boot device |
| -1 common/cmd_ide.c Unknown partition table |
| -1 common/cmd_ide.c Invalid partition type |
| -1 common/cmd_ide.c Read Error on boot device |
| -1 common/cmd_ide.c Image header has bad magic number |
| |
| -1 common/cmd_nvedit.c Environment not changable, but has bad CRC |
| |
| |
| Modem Support: |
| -------------- |
| |
| [so far only for SMDK2400 board] |
| |
| - Modem support endable: |
| CONFIG_MODEM_SUPPORT |
| |
| - RTS/CTS Flow control enable: |
| CONFIG_HWFLOW |
| |
| - Modem debug support: |
| CONFIG_MODEM_SUPPORT_DEBUG |
| |
| Enables debugging stuff (char screen[1024], dbg()) |
| for modem support. Useful only with BDI2000. |
| |
| - General: |
| |
| In the target system modem support is enabled when a |
| specific key (key combination) is pressed during |
| power-on. Otherwise U-Boot will boot normally |
| (autoboot). The key_pressed() fuction is called from |
| board_init(). Currently key_pressed() is a dummy |
| function, returning 1 and thus enabling modem |
| initialization. |
| |
| If there are no modem init strings in the |
| environment, U-Boot proceed to autoboot; the |
| previous output (banner, info printfs) will be |
| supressed, though. |
| |
| See also: doc/README.Modem |
| |
| |
| |
| |
| Configuration Settings: |
| ----------------------- |
| |
| - CFG_LONGHELP: Defined when you want long help messages included; |
| undefine this when you're short of memory. |
| |
| - CFG_PROMPT: This is what U-Boot prints on the console to |
| prompt for user input. |
| |
| - CFG_CBSIZE: Buffer size for input from the Console |
| |
| - CFG_PBSIZE: Buffer size for Console output |
| |
| - CFG_MAXARGS: max. Number of arguments accepted for monitor commands |
| |
| - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to |
| the application (usually a Linux kernel) when it is |
| booted |
| |
| - CFG_BAUDRATE_TABLE: |
| List of legal baudrate settings for this board. |
| |
| - CFG_CONSOLE_INFO_QUIET |
| Suppress display of console information at boot. |
| |
| - CFG_CONSOLE_IS_IN_ENV |
| If the board specific function |
| extern int overwrite_console (void); |
| returns 1, the stdin, stderr and stdout are switched to the |
| serial port, else the settings in the environment are used. |
| |
| - CFG_CONSOLE_OVERWRITE_ROUTINE |
| Enable the call to overwrite_console(). |
| |
| - CFG_CONSOLE_ENV_OVERWRITE |
| Enable overwrite of previous console environment settings. |
| |
| - CFG_MEMTEST_START, CFG_MEMTEST_END: |
| Begin and End addresses of the area used by the |
| simple memory test. |
| |
| - CFG_ALT_MEMTEST: |
| Enable an alternate, more extensive memory test. |
| |
| - CFG_TFTP_LOADADDR: |
| Default load address for network file downloads |
| |
| - CFG_LOADS_BAUD_CHANGE: |
| Enable temporary baudrate change while serial download |
| |
| - CFG_SDRAM_BASE: |
| Physical start address of SDRAM. _Must_ be 0 here. |
| |
| - CFG_MBIO_BASE: |
| Physical start address of Motherboard I/O (if using a |
| Cogent motherboard) |
| |
| - CFG_FLASH_BASE: |
| Physical start address of Flash memory. |
| |
| - CFG_MONITOR_BASE: |
| Physical start address of boot monitor code (set by |
| make config files to be same as the text base address |
| (TEXT_BASE) used when linking) - same as |
| CFG_FLASH_BASE when booting from flash. |
| |
| - CFG_MONITOR_LEN: |
| Size of memory reserved for monitor code |
| |
| - CFG_MALLOC_LEN: |
| Size of DRAM reserved for malloc() use. |
| |
| - CFG_BOOTMAPSZ: |
| Maximum size of memory mapped by the startup code of |
| the Linux kernel; all data that must be processed by |
| the Linux kernel (bd_info, boot arguments, eventually |
| initrd image) must be put below this limit. |
| |
| - CFG_MAX_FLASH_BANKS: |
| Max number of Flash memory banks |
| |
| - CFG_MAX_FLASH_SECT: |
| Max number of sectors on a Flash chip |
| |
| - CFG_FLASH_ERASE_TOUT: |
| Timeout for Flash erase operations (in ms) |
| |
| - CFG_FLASH_WRITE_TOUT: |
| Timeout for Flash write operations (in ms) |
| |
| - CFG_DIRECT_FLASH_TFTP: |
| |
| Enable TFTP transfers directly to flash memory; |
| without this option such a download has to be |
| performed in two steps: (1) download to RAM, and (2) |
| copy from RAM to flash. |
| |
| The two-step approach is usually more reliable, since |
| you can check if the download worked before you erase |
| the flash, but in some situations (when sytem RAM is |
| too limited to allow for a tempory copy of the |
| downloaded image) this option may be very useful. |
| |
| - CFG_FLASH_CFI: |
| Define if the flash driver uses extra elements in the |
| common flash structure for storing flash geometry |
| |
| The following definitions that deal with the placement and management |
| of environment data (variable area); in general, we support the |
| following configurations: |
| |
| - CFG_ENV_IS_IN_FLASH: |
| |
| Define this if the environment is in flash memory. |
| |
| a) The environment occupies one whole flash sector, which is |
| "embedded" in the text segment with the U-Boot code. This |
| happens usually with "bottom boot sector" or "top boot |
| sector" type flash chips, which have several smaller |
| sectors at the start or the end. For instance, such a |
| layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In |
| such a case you would place the environment in one of the |
| 4 kB sectors - with U-Boot code before and after it. With |
| "top boot sector" type flash chips, you would put the |
| environment in one of the last sectors, leaving a gap |
| between U-Boot and the environment. |
| |
| - CFG_ENV_OFFSET: |
| |
| Offset of environment data (variable area) to the |
| beginning of flash memory; for instance, with bottom boot |
| type flash chips the second sector can be used: the offset |
| for this sector is given here. |
| |
| CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. |
| |
| - CFG_ENV_ADDR: |
| |
| This is just another way to specify the start address of |
| the flash sector containing the environment (instead of |
| CFG_ENV_OFFSET). |
| |
| - CFG_ENV_SECT_SIZE: |
| |
| Size of the sector containing the environment. |
| |
| |
| b) Sometimes flash chips have few, equal sized, BIG sectors. |
| In such a case you don't want to spend a whole sector for |
| the environment. |
| |
| - CFG_ENV_SIZE: |
| |
| If you use this in combination with CFG_ENV_IS_IN_FLASH |
| and CFG_ENV_SECT_SIZE, you can specify to use only a part |
| of this flash sector for the environment. This saves |
| memory for the RAM copy of the environment. |
| |
| It may also save flash memory if you decide to use this |
| when your environment is "embedded" within U-Boot code, |
| since then the remainder of the flash sector could be used |
| for U-Boot code. It should be pointed out that this is |
| STRONGLY DISCOURAGED from a robustness point of view: |
| updating the environment in flash makes it always |
| necessary to erase the WHOLE sector. If something goes |
| wrong before the contents has been restored from a copy in |
| RAM, your target system will be dead. |
| |
| - CFG_ENV_ADDR_REDUND |
| CFG_ENV_SIZE_REDUND |
| |
| These settings describe a second storage area used to hold |
| a redundand copy of the environment data, so that there is |
| a valid backup copy in case there is a power failur during |
| a "saveenv" operation. |
| |
| BE CAREFUL! Any changes to the flash layout, and some changes to the |
| source code will make it necessary to adapt <board>/u-boot.lds* |
| accordingly! |
| |
| |
| - CFG_ENV_IS_IN_NVRAM: |
| |
| Define this if you have some non-volatile memory device |
| (NVRAM, battery buffered SRAM) which you want to use for the |
| environment. |
| |
| - CFG_ENV_ADDR: |
| - CFG_ENV_SIZE: |
| |
| These two #defines are used to determin the memory area you |
| want to use for environment. It is assumed that this memory |
| can just be read and written to, without any special |
| provision. |
| |
| BE CAREFUL! The first access to the environment happens quite early |
| in U-Boot initalization (when we try to get the setting of for the |
| console baudrate). You *MUST* have mappend your NVRAM area then, or |
| U-Boot will hang. |
| |
| Please note that even with NVRAM we still use a copy of the |
| environment in RAM: we could work on NVRAM directly, but we want to |
| keep settings there always unmodified except somebody uses "saveenv" |
| to save the current settings. |
| |
| |
| - CFG_ENV_IS_IN_EEPROM: |
| |
| Use this if you have an EEPROM or similar serial access |
| device and a driver for it. |
| |
| - CFG_ENV_OFFSET: |
| - CFG_ENV_SIZE: |
| |
| These two #defines specify the offset and size of the |
| environment area within the total memory of your EEPROM. |
| |
| - CFG_I2C_EEPROM_ADDR: |
| If defined, specified the chip address of the EEPROM device. |
| The default address is zero. |
| |
| - CFG_EEPROM_PAGE_WRITE_BITS: |
| If defined, the number of bits used to address bytes in a |
| single page in the EEPROM device. A 64 byte page, for example |
| would require six bits. |
| |
| - CFG_EEPROM_PAGE_WRITE_DELAY_MS: |
| If defined, the number of milliseconds to delay between |
| page writes. The default is zero milliseconds. |
| |
| - CFG_I2C_EEPROM_ADDR_LEN: |
| The length in bytes of the EEPROM memory array address. Note |
| that this is NOT the chip address length! |
| |
| - CFG_EEPROM_SIZE: |
| The size in bytes of the EEPROM device. |
| |
| |
| - CFG_SPI_INIT_OFFSET |
| |
| Defines offset to the initial SPI buffer area in DPRAM. The |
| area is used at an early stage (ROM part) if the environment |
| is configured to reside in the SPI EEPROM: We need a 520 byte |
| scratch DPRAM area. It is used between the two initialization |
| calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems |
| to be a good choice since it makes it far enough from the |
| start of the data area as well as from the stack pointer. |
| |
| Please note that the environment is read-only as long as the monitor |
| has been relocated to RAM and a RAM copy of the environment has been |
| created; also, when using EEPROM you will have to use getenv_r() |
| until then to read environment variables. |
| |
| The environment is now protected by a CRC32 checksum. Before the |
| monitor is relocated into RAM, as a result of a bad CRC you will be |
| working with the compiled-in default environment - *silently*!!! |
| [This is necessary, because the first environment variable we need is |
| the "baudrate" setting for the console - if we have a bad CRC, we |
| don't have any device yet where we could complain.] |
| |
| Note: once the monitor has been relocated, then it will complain if |
| the default environment is used; a new CRC is computed as soon as you |
| use the "setenv" command to modify / delete / add any environment |
| variable [even when you try to delete a non-existing variable!]. |
| |
| Note2: you must edit your u-boot.lds file to reflect this |
| configuration. |
| |
| |
| Low Level (hardware related) configuration options: |
| |
| - CFG_CACHELINE_SIZE: |
| Cache Line Size of the CPU. |
| |
| - CFG_DEFAULT_IMMR: |
| Default address of the IMMR after system reset. |
| Needed on some 8260 systems (MPC8260ADS and RPXsuper) |
| to be able to adjust the position of the IMMR |
| register after a reset. |
| |
| - Floppy Disk Support: |
| CFG_FDC_DRIVE_NUMBER |
| |
| the default drive number (default value 0) |
| |
| CFG_ISA_IO_STRIDE |
| |
| defines the spacing between fdc chipset registers |
| (default value 1) |
| |
| CFG_ISA_IO_OFFSET |
| |
| defines the offset of register from address. It |
| depends on which part of the data bus is connected to |
| the fdc chipset. (default value 0) |
| |
| If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and |
| CFG_FDC_DRIVE_NUMBER are undefined, they take their |
| default value. |
| |
| if CFG_FDC_HW_INIT is defined, then the function |
| fdc_hw_init() is called at the beginning of the FDC |
| setup. fdc_hw_init() must be provided by the board |
| source code. It is used to make hardware dependant |
| initializations. |
| |
| - CFG_IMMR: Physical address of the Internal Memory Mapped |
| Register; DO NOT CHANGE! (11-4) |
| [MPC8xx systems only] |
| |
| - CFG_INIT_RAM_ADDR: |
| |
| Start address of memory area tha can be used for |
| initial data and stack; please note that this must be |
| writable memory that is working WITHOUT special |
| initialization, i. e. you CANNOT use normal RAM which |
| will become available only after programming the |
| memory controller and running certain initialization |
| sequences. |
| |
| U-Boot uses the following memory types: |
| - MPC8xx and MPC8260: IMMR (internal memory of the CPU) |
| - MPC824X: data cache |
| - PPC4xx: data cache |
| |
| - CFG_INIT_DATA_OFFSET: |
| |
| Offset of the initial data structure in the memory |
| area defined by CFG_INIT_RAM_ADDR. Usually |
| CFG_INIT_DATA_OFFSET is chosen such that the initial |
| data is located at the end of the available space |
| (sometimes written as (CFG_INIT_RAM_END - |
| CFG_INIT_DATA_SIZE), and the initial stack is just |
| below that area (growing from (CFG_INIT_RAM_ADDR + |
| CFG_INIT_DATA_OFFSET) downward. |
| |
| Note: |
| On the MPC824X (or other systems that use the data |
| cache for initial memory) the address chosen for |
| CFG_INIT_RAM_ADDR is basically arbitrary - it must |
| point to an otherwise UNUSED address space between |
| the top of RAM and the start of the PCI space. |
| |
| - CFG_SIUMCR: SIU Module Configuration (11-6) |
| |
| - CFG_SYPCR: System Protection Control (11-9) |
| |
| - CFG_TBSCR: Time Base Status and Control (11-26) |
| |
| - CFG_PISCR: Periodic Interrupt Status and Control (11-31) |
| |
| - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) |
| |
| - CFG_SCCR: System Clock and reset Control Register (15-27) |
| |
| - CFG_OR_TIMING_SDRAM: |
| SDRAM timing |
| |
| - CFG_MAMR_PTA: |
| periodic timer for refresh |
| |
| - CFG_DER: Debug Event Register (37-47) |
| |
| - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, |
| CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, |
| CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, |
| CFG_BR1_PRELIM: |
| Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) |
| |
| - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, |
| CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, |
| CFG_OR3_PRELIM, CFG_BR3_PRELIM: |
| Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) |
| |
| - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, |
| CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: |
| Machine Mode Register and Memory Periodic Timer |
| Prescaler definitions (SDRAM timing) |
| |
| - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: |
| enable I2C microcode relocation patch (MPC8xx); |
| define relocation offset in DPRAM [DSP2] |
| |
| - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: |
| enable SPI microcode relocation patch (MPC8xx); |
| define relocation offset in DPRAM [SCC4] |
| |
| - CFG_USE_OSCCLK: |
| Use OSCM clock mode on MBX8xx board. Be careful, |
| wrong setting might damage your board. Read |
| doc/README.MBX before setting this variable! |
| |
| - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) |
| Offset of the bootmode word in DPRAM used by post |
| (Power On Self Tests). This definition overrides |
| #define'd default value in commproc.h resp. |
| cpm_8260.h. |
| |
| Building the Software: |
| ====================== |
| |
| Building U-Boot has been tested in native PPC environments (on a |
| PowerBook G3 running LinuxPPC 2000) and in cross environments |
| (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and |
| NetBSD 1.5 on x86). |
| |
| If you are not using a native PPC environment, it is assumed that you |
| have the GNU cross compiling tools available in your path and named |
| with a prefix of "powerpc-linux-". If this is not the case, (e.g. if |
| you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change |
| the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU, |
| change it to: |
| |
| CROSS_COMPILE = ppc_4xx- |
| |
| |
| U-Boot is intended to be simple to build. After installing the |
| sources you must configure U-Boot for one specific board type. This |
| is done by typing: |
| |
| make NAME_config |
| |
| where "NAME_config" is the name of one of the existing |
| configurations; the following names are supported: |
| |
| ADCIOP_config GTH_config TQM850L_config |
| ADS860_config IP860_config TQM855L_config |
| AR405_config IVML24_config TQM860L_config |
| CANBT_config IVMS8_config WALNUT405_config |
| CPCI405_config LANTEC_config cogent_common_config |
| CPCIISER4_config MBX_config cogent_mpc8260_config |
| CU824_config MBX860T_config cogent_mpc8xx_config |
| ESTEEM192E_config RPXlite_config hermes_config |
| ETX094_config RPXsuper_config hymod_config |
| FADS823_config SM850_config lwmon_config |
| FADS850SAR_config SPD823TS_config pcu_e_config |
| FADS860T_config SXNI855T_config rsdproto_config |
| FPS850L_config Sandpoint8240_config sbc8260_config |
| GENIETV_config TQM823L_config PIP405_config |
| GEN860T_config EBONY_config FPS860L_config |
| |
| Note: for some board special configuration names may exist; check if |
| additional information is available from the board vendor; for |
| instance, the TQM8xxL systems run normally at 50 MHz and use a |
| SCC for 10baseT ethernet; there are also systems with 80 MHz |
| CPU clock, and an optional Fast Ethernet module is available |
| for CPU's with FEC. You can select such additional "features" |
| when chosing the configuration, i. e. |
| |
| make TQM860L_config |
| - will configure for a plain TQM860L, i. e. 50MHz, no FEC |
| |
| make TQM860L_FEC_config |
| - will configure for a TQM860L at 50MHz with FEC for ethernet |
| |
| make TQM860L_80MHz_config |
| - will configure for a TQM860L at 80 MHz, with normal 10baseT |
| interface |
| |
| make TQM860L_FEC_80MHz_config |
| - will configure for a TQM860L at 80 MHz with FEC for ethernet |
| |
| make TQM823L_LCD_config |
| - will configure for a TQM823L with U-Boot console on LCD |
| |
| make TQM823L_LCD_80MHz_config |
| - will configure for a TQM823L at 80 MHz with U-Boot console on LCD |
| |
| etc. |
| |
| |
| |
| Finally, type "make all", and you should get some working U-Boot |
| images ready for downlod to / installation on your system: |
| |
| - "u-boot.bin" is a raw binary image |
| - "u-boot" is an image in ELF binary format |
| - "u-boot.srec" is in Motorola S-Record format |
| |
| |
| Please be aware that the Makefiles assume you are using GNU make, so |
| for instance on NetBSD you might need to use "gmake" instead of |
| native "make". |
| |
| |
| If the system board that you have is not listed, then you will need |
| to port U-Boot to your hardware platform. To do this, follow these |
| steps: |
| |
| 1. Add a new configuration option for your board to the toplevel |
| "Makefile", using the existing entries as examples. |
| 2. Create a new directory to hold your board specific code. Add any |
| files you need. |
| 3. If you're porting U-Boot to a new CPU, then also create a new |
| directory to hold your CPU specific code. Add any files you need. |
| 4. Run "make config_name" with your new name. |
| 5. Type "make", and you should get a working "u-boot.srec" file |
| to be installed on your target system. |
| [Of course, this last step is much harder than it sounds.] |
| |
| |
| Testing of U-Boot Modifications, Ports to New Hardware, etc.: |
| ============================================================== |
| |
| If you have modified U-Boot sources (for instance added a new board |
| or support for new devices, a new CPU, etc.) you are expected to |
| provide feedback to the other developers. The feedback normally takes |
| the form of a "patch", i. e. a context diff against a certain (latest |
| official or latest in CVS) version of U-Boot sources. |
| |
| But before you submit such a patch, please verify that your modifi- |
| cation did not break existing code. At least make sure that *ALL* of |
| the supported boards compile WITHOUT ANY compiler warnings. To do so, |
| just run the "MAKEALL" script, which will configure and build U-Boot |
| for ALL supported system. Be warned, this will take a while. You can |
| select which (cross) compiler to use py passing a `CROSS_COMPILE' |
| environment variable to the script, i. e. to use the cross tools from |
| MontaVista's Hard Hat Linux you can type |
| |
| CROSS_COMPILE=ppc_8xx- MAKEALL |
| |
| or to build on a native PowerPC system you can type |
| |
| CROSS_COMPILE=' ' MAKEALL |
| |
| See also "U-Boot Porting Guide" below. |
| |
| |
| |
| Monitor Commands - Overview: |
| ============================ |
| |
| go - start application at address 'addr' |
| run - run commands in an environment variable |
| bootm - boot application image from memory |
| bootp - boot image via network using BootP/TFTP protocol |
| tftpboot- boot image via network using TFTP protocol |
| and env variables "ipaddr" and "serverip" |
| (and eventually "gatewayip") |
| rarpboot- boot image via network using RARP/TFTP protocol |
| diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' |
| loads - load S-Record file over serial line |
| loadb - load binary file over serial line (kermit mode) |
| md - memory display |
| mm - memory modify (auto-incrementing) |
| nm - memory modify (constant address) |
| mw - memory write (fill) |
| cp - memory copy |
| cmp - memory compare |
| crc32 - checksum calculation |
| imd - i2c memory display |
| imm - i2c memory modify (auto-incrementing) |
| inm - i2c memory modify (constant address) |
| imw - i2c memory write (fill) |
| icrc32 - i2c checksum calculation |
| iprobe - probe to discover valid I2C chip addresses |
| iloop - infinite loop on address range |
| isdram - print SDRAM configuration information |
| sspi - SPI utility commands |
| base - print or set address offset |
| printenv- print environment variables |
| setenv - set environment variables |
| saveenv - save environment variables to persistent storage |
| protect - enable or disable FLASH write protection |
| erase - erase FLASH memory |
| flinfo - print FLASH memory information |
| bdinfo - print Board Info structure |
| iminfo - print header information for application image |
| coninfo - print console devices and informations |
| ide - IDE sub-system |
| loop - infinite loop on address range |
| mtest - simple RAM test |
| icache - enable or disable instruction cache |
| dcache - enable or disable data cache |
| reset - Perform RESET of the CPU |
| echo - echo args to console |
| version - print monitor version |
| help - print online help |
| ? - alias for 'help' |
| |
| |
| Monitor Commands - Detailed Description: |
| ======================================== |
| |
| TODO. |
| |
| For now: just type "help <command>". |
| |
| |
| Environment Variables: |
| ====================== |
| |
| U-Boot supports user configuration using Environment Variables which |
| can be made persistent by saving to Flash memory. |
| |
| Environment Variables are set using "setenv", printed using |
| "printenv", and saved to Flash using "saveenv". Using "setenv" |
| without a value can be used to delete a variable from the |
| environment. As long as you don't save the environment you are |
| working with an in-memory copy. In case the Flash area containing the |
| environment is erased by accident, a default environment is provided. |
| |
| Some configuration options can be set using Environment Variables: |
| |
| baudrate - see CONFIG_BAUDRATE |
| |
| bootdelay - see CONFIG_BOOTDELAY |
| |
| bootcmd - see CONFIG_BOOTCOMMAND |
| |
| bootargs - Boot arguments when booting an RTOS image |
| |
| bootfile - Name of the image to load with TFTP |
| |
| autoload - if set to "no" (any string beginning with 'n'), |
| "bootp" will just load perform a lookup of the |
| configuration from the BOOTP server, but not try to |
| load any image using TFTP |
| |
| autostart - if set to "yes", an image loaded using the "bootp", |
| "rarpboot", "tftpboot" or "diskboot" commands will |
| be automatically started (by internally calling |
| "bootm") |
| |
| initrd_high - restrict positioning of initrd images: |
| If this variable is not set, initrd images will be |
| copied to the highest possible address in RAM; this |
| is usually what you want since it allows for |
| maximum initrd size. If for some reason you want to |
| make sure that the initrd image is loaded below the |
| CFG_BOOTMAPSZ limit, you can set this environment |
| variable to a value of "no" or "off" or "0". |
| Alternatively, you can set it to a maximum upper |
| address to use (U-Boot will still check that it |
| does not overwrite the U-Boot stack and data). |
| |
| For instance, when you have a system with 16 MB |
| RAM, and want to reseve 4 MB from use by Linux, |
| you can do this by adding "mem=12M" to the value of |
| the "bootargs" variable. However, now you must make |
| sure, that the initrd image is placed in the first |
| 12 MB as well - this can be done with |
| |
| setenv initrd_high 00c00000 |
| |
| ipaddr - IP address; needed for tftpboot command |
| |
| loadaddr - Default load address for commands like "bootp", |
| "rarpboot", "tftpboot" or "diskboot" |
| |
| loads_echo - see CONFIG_LOADS_ECHO |
| |
| serverip - TFTP server IP address; needed for tftpboot command |
| |
| bootretry - see CONFIG_BOOT_RETRY_TIME |
| |
| bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR |
| |
| bootstopkey - see CONFIG_AUTOBOOT_STOP_STR |
| |
| |
| The following environment variables may be used and automatically |
| updated by the network boot commands ("bootp" and "rarpboot"), |
| depending the information provided by your boot server: |
| |
| bootfile - see above |
| dnsip - IP address of your Domain Name Server |
| gatewayip - IP address of the Gateway (Router) to use |
| hostname - Target hostname |
| ipaddr - see above |
| netmask - Subnet Mask |
| rootpath - Pathname of the root filesystem on the NFS server |
| serverip - see above |
| |
| |
| There are two special Environment Variables: |
| |
| serial# - contains hardware identification information such |
| as type string and/or serial number |
| ethaddr - Ethernet address |
| |
| These variables can be set only once (usually during manufacturing of |
| the board). U-Boot refuses to delete or overwrite these variables |
| once they have been set once. |
| |
| |
| Please note that changes to some configuration parameters may take |
| only effect after the next boot (yes, that's just like Windoze :-). |
| |
| |
| Note for Redundant Ethernet Interfaces: |
| ======================================= |
| |
| Some boards come with redundand ethernet interfaces; U-Boot supports |
| such configurations and is capable of automatic selection of a |
| "working" interface when needed. MAC assignemnt works as follows: |
| |
| Network interfaces are numbered eth0, eth1, eth2, ... Corresponding |
| MAC addresses can be stored in the environment as "ethaddr" (=>eth0), |
| "eth1addr" (=>eth1), "eth2addr", ... |
| |
| If the network interface stores some valid MAC address (for instance |
| in SROM), this is used as default address if there is NO correspon- |
| ding setting in the environment; if the corresponding environment |
| variable is set, this overrides the settings in the card; that means: |
| |
| o If the SROM has a valid MAC address, and there is no address in the |
| environment, the SROM's address is used. |
| |
| o If there is no valid address in the SROM, and a definition in the |
| environment exists, then the value from the environment variable is |
| used. |
| |
| o If both the SROM and the environment contain a MAC address, and |
| both addresses are the same, this MAC address is used. |
| |
| o If both the SROM and the environment contain a MAC address, and the |
| addresses differ, the value from the environment is used and a |
| warning is printed. |
| |
| o If neither SROM nor the environment contain a MAC address, an error |
| is raised. |
| |
| |
| |
| Image Formats: |
| ============== |
| |
| The "boot" commands of this monitor operate on "image" files which |
| can be basicly anything, preceeded by a special header; see the |
| definitions in include/image.h for details; basicly, the header |
| defines the following image properties: |
| |
| * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, |
| 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, |
| LynxOS, pSOS, QNX; |
| Currently supported: Linux, NetBSD, VxWorks, QNX). |
| * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, |
| IA64, MIPS, MIPS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; |
| Currently supported: PowerPC). |
| * Compression Type (Provisions for uncompressed, gzip, bzip2; |
| Currently supported: uncompressed, gzip). |
| * Load Address |
| * Entry Point |
| * Image Name |
| * Image Timestamp |
| |
| The header is marked by a special Magic Number, and both the header |
| and the data portions of the image are secured against corruption by |
| CRC32 checksums. |
| |
| |
| Linux Support: |
| ============== |
| |
| Although U-Boot should support any OS or standalone application |
| easily, Linux has always been in the focus during the design of |
| U-Boot. |
| |
| U-Boot includes many features that so far have been part of some |
| special "boot loader" code within the Linux kernel. Also, any |
| "initrd" images to be used are no longer part of one big Linux image; |
| instead, kernel and "initrd" are separate images. This implementation |
| serves serveral purposes: |
| |
| - the same features can be used for other OS or standalone |
| applications (for instance: using compressed images to reduce the |
| Flash memory footprint) |
| |
| - it becomes much easier to port new Linux kernel versions because |
| lots of low-level, hardware dependend stuff are done by U-Boot |
| |
| - the same Linux kernel image can now be used with different "initrd" |
| images; of course this also means that different kernel images can |
| be run with the same "initrd". This makes testing easier (you don't |
| have to build a new "zImage.initrd" Linux image when you just |
| change a file in your "initrd"). Also, a field-upgrade of the |
| software is easier now. |
| |
| |
| Linux HOWTO: |
| ============ |
| |
| Porting Linux to U-Boot based systems: |
| --------------------------------------- |
| |
| U-Boot cannot save you from doing all the necessary modifications to |
| configure the Linux device drivers for use with your target hardware |
| (no, we don't intend to provide a full virtual machine interface to |
| Linux :-). |
| |
| But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). |
| |
| Just make sure your machine specific header file (for instance |
| include/asm-ppc/tqm8xx.h) includes the same definition of the Board |
| Information structure as we define in include/u-boot.h, and make |
| sure that your definition of IMAP_ADDR uses the same value as your |
| U-Boot configuration in CFG_IMMR. |
| |
| |
| Configuring the Linux kernel: |
| ----------------------------- |
| |
| No specific requirements for U-Boot. Make sure you have some root |
| device (initial ramdisk, NFS) for your target system. |
| |
| |
| Building a Linux Image: |
| ----------------------- |
| |
| With U-Boot, "normal" build targets like "zImage" or "bzImage" are |
| not used. If you use recent kernel source, a new build target |
| "uImage" will exist which automatically builds an image usable by |
| U-Boot. Most older kernels also have support for a "pImage" target, |
| which was introduced for our predecessor project PPCBoot and uses a |
| 100% compatible format. |
| |
| Example: |
| |
| make TQM850L_config |
| make oldconfig |
| make dep |
| make uImage |
| |
| The "uImage" build target uses a special tool (in 'tools/mkimage') to |
| encapsulate a compressed Linux kernel image with header information, |
| CRC32 checksum etc. for use with U-Boot. This is what we are doing: |
| |
| * build a standard "vmlinux" kernel image (in ELF binary format): |
| |
| * convert the kernel into a raw binary image: |
| |
| ${CROSS_COMPILE}-objcopy -O binary \ |
| -R .note -R .comment \ |
| -S vmlinux linux.bin |
| |
| * compress the binary image: |
| |
| gzip -9 linux.bin |
| |
| * package compressed binary image for U-Boot: |
| |
| mkimage -A ppc -O linux -T kernel -C gzip \ |
| -a 0 -e 0 -n "Linux Kernel Image" \ |
| -d linux.bin.gz uImage |
| |
| |
| The "mkimage" tool can also be used to create ramdisk images for use |
| with U-Boot, either separated from the Linux kernel image, or |
| combined into one file. "mkimage" encapsulates the images with a 64 |
| byte header containing information about target architecture, |
| operating system, image type, compression method, entry points, time |
| stamp, CRC32 checksums, etc. |
| |
| "mkimage" can be called in two ways: to verify existing images and |
| print the header information, or to build new images. |
| |
| In the first form (with "-l" option) mkimage lists the information |
| contained in the header of an existing U-Boot image; this includes |
| checksum verification: |
| |
| tools/mkimage -l image |
| -l ==> list image header information |
| |
| The second form (with "-d" option) is used to build a U-Boot image |
| from a "data file" which is used as image payload: |
| |
| tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ |
| -n name -d data_file image |
| -A ==> set architecture to 'arch' |
| -O ==> set operating system to 'os' |
| -T ==> set image type to 'type' |
| -C ==> set compression type 'comp' |
| -a ==> set load address to 'addr' (hex) |
| -e ==> set entry point to 'ep' (hex) |
| -n ==> set image name to 'name' |
| -d ==> use image data from 'datafile' |
| |
| Right now, all Linux kernels use the same load address (0x00000000), |
| but the entry point address depends on the kernel version: |
| |
| - 2.2.x kernels have the entry point at 0x0000000C, |
| - 2.3.x and later kernels have the entry point at 0x00000000. |
| |
| So a typical call to build a U-Boot image would read: |
| |
| -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ |
| > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ |
| > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ |
| > examples/uImage.TQM850L |
| Image Name: 2.4.4 kernel for TQM850L |
| Created: Wed Jul 19 02:34:59 2000 |
| Image Type: PowerPC Linux Kernel Image (gzip compressed) |
| Data Size: 335725 Bytes = 327.86 kB = 0.32 MB |
| Load Address: 0x00000000 |
| Entry Point: 0x00000000 |
| |
| To verify the contents of the image (or check for corruption): |
| |
| -> tools/mkimage -l examples/uImage.TQM850L |
| Image Name: 2.4.4 kernel for TQM850L |
| Created: Wed Jul 19 02:34:59 2000 |
| Image Type: PowerPC Linux Kernel Image (gzip compressed) |
| Data Size: 335725 Bytes = 327.86 kB = 0.32 MB |
| Load Address: 0x00000000 |
| Entry Point: 0x00000000 |
| |
| NOTE: for embedded systems where boot time is critical you can trade |
| speed for memory and install an UNCOMPRESSED image instead: this |
| needs more space in Flash, but boots much faster since it does not |
| need to be uncompressed: |
| |
| -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz |
| -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ |
| > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ |
| > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ |
| > examples/uImage.TQM850L-uncompressed |
| Image Name: 2.4.4 kernel for TQM850L |
| Created: Wed Jul 19 02:34:59 2000 |
| Image Type: PowerPC Linux Kernel Image (uncompressed) |
| Data Size: 792160 Bytes = 773.59 kB = 0.76 MB |
| Load Address: 0x00000000 |
| Entry Point: 0x00000000 |
| |
| |
| Similar you can build U-Boot images from a 'ramdisk.image.gz' file |
| when your kernel is intended to use an initial ramdisk: |
| |
| -> tools/mkimage -n 'Simple Ramdisk Image' \ |
| > -A ppc -O linux -T ramdisk -C gzip \ |
| > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd |
| Image Name: Simple Ramdisk Image |
| Created: Wed Jan 12 14:01:50 2000 |
| Image Type: PowerPC Linux RAMDisk Image (gzip compressed) |
| Data Size: 566530 Bytes = 553.25 kB = 0.54 MB |
| Load Address: 0x00000000 |
| Entry Point: 0x00000000 |
| |
| |
| Installing a Linux Image: |
| ------------------------- |
| |
| To downloading a U-Boot image over the serial (console) interface, |
| you must convert the image to S-Record format: |
| |
| objcopy -I binary -O srec examples/image examples/image.srec |
| |
| The 'objcopy' does not understand the information in the U-Boot |
| image header, so the resulting S-Record file will be relative to |
| address 0x00000000. To load it to a given address, you need to |
| specify the target address as 'offset' parameter with the 'loads' |
| command. |
| |
| Example: install the image to address 0x40100000 (which on the |
| TQM8xxL is in the first Flash bank): |
| |
| => erase 40100000 401FFFFF |
| |
| .......... done |
| Erased 8 sectors |
| |
| => loads 40100000 |
| ## Ready for S-Record download ... |
| ~>examples/image.srec |
| 1 2 3 4 5 6 7 8 9 10 11 12 13 ... |
| ... |
| 15989 15990 15991 15992 |
| [file transfer complete] |
| [connected] |
| ## Start Addr = 0x00000000 |
| |
| |
| You can check the success of the download using the 'iminfo' command; |
| this includes a checksum verification so you can be sure no data |
| corruption happened: |
| |
| => imi 40100000 |
| |
| ## Checking Image at 40100000 ... |
| Image Name: 2.2.13 for initrd on TQM850L |
| Image Type: PowerPC Linux Kernel Image (gzip compressed) |
| Data Size: 335725 Bytes = 327 kB = 0 MB |
| Load Address: 00000000 |
| Entry Point: 0000000c |
| Verifying Checksum ... OK |
| |
| |
| |
| Boot Linux: |
| ----------- |
| |
| The "bootm" command is used to boot an application that is stored in |
| memory (RAM or Flash). In case of a Linux kernel image, the contents |
| of the "bootargs" environment variable is passed to the kernel as |
| parameters. You can check and modify this variable using the |
| "printenv" and "setenv" commands: |
| |
| |
| => printenv bootargs |
| bootargs=root=/dev/ram |
| |
| => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 |
| |
| => printenv bootargs |
| bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 |
| |
| => bootm 40020000 |
| ## Booting Linux kernel at 40020000 ... |
| Image Name: 2.2.13 for NFS on TQM850L |
| Image Type: PowerPC Linux Kernel Image (gzip compressed) |
| Data Size: 381681 Bytes = 372 kB = 0 MB |
| Load Address: 00000000 |
| Entry Point: 0000000c |
| Verifying Checksum ... OK |
| Uncompressing Kernel Image ... OK |
| Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000 |
| Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 |
| time_init: decrementer frequency = 187500000/60 |
| Calibrating delay loop... 49.77 BogoMIPS |
| Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] |
| ... |
| |
| If you want to boot a Linux kernel with initial ram disk, you pass |
| the memory addreses of both the kernel and the initrd image (PPBCOOT |
| format!) to the "bootm" command: |
| |
| => imi 40100000 40200000 |
| |
| ## Checking Image at 40100000 ... |
| Image Name: 2.2.13 for initrd on TQM850L |
| Image Type: PowerPC Linux Kernel Image (gzip compressed) |
| Data Size: 335725 Bytes = 327 kB = 0 MB |
| Load Address: 00000000 |
| Entry Point: 0000000c |
| Verifying Checksum ... OK |
| |
| ## Checking Image at 40200000 ... |
| Image Name: Simple Ramdisk Image |
| Image Type: PowerPC Linux RAMDisk Image (gzip compressed) |
| Data Size: 566530 Bytes = 553 kB = 0 MB |
| Load Address: 00000000 |
| Entry Point: 00000000 |
| Verifying Checksum ... OK |
| |
| => bootm 40100000 40200000 |
| ## Booting Linux kernel at 40100000 ... |
| Image Name: 2.2.13 for initrd on TQM850L |
| Image Type: PowerPC Linux Kernel Image (gzip compressed) |
| Data Size: 335725 Bytes = 327 kB = 0 MB |
| Load Address: 00000000 |
| Entry Point: 0000000c |
| Verifying Checksum ... OK |
| Uncompressing Kernel Image ... OK |
| ## Loading RAMDisk Image at 40200000 ... |
| Image Name: Simple Ramdisk Image |
| Image Type: PowerPC Linux RAMDisk Image (gzip compressed) |
| Data Size: 566530 Bytes = 553 kB = 0 MB |
| Load Address: 00000000 |
| Entry Point: 00000000 |
| Verifying Checksum ... OK |
| Loading Ramdisk ... OK |
| Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000 |
| Boot arguments: root=/dev/ram |
| time_init: decrementer frequency = 187500000/60 |
| Calibrating delay loop... 49.77 BogoMIPS |
| ... |
| RAMDISK: Compressed image found at block 0 |
| VFS: Mounted root (ext2 filesystem). |
| |
| bash# |
| |
| More About U-Boot Image Types: |
| ------------------------------ |
| |
| U-Boot supports the following image types: |
| |
| "Standalone Programs" are directly runnable in the environment |
| provided by U-Boot; it is expected that (if they behave |
| well) you can continue to work in U-Boot after return from |
| the Standalone Program. |
| "OS Kernel Images" are usually images of some Embedded OS which |
| will take over control completely. Usually these programs |
| will install their own set of exception handlers, device |
| drivers, set up the MMU, etc. - this means, that you cannot |
| expect to re-enter U-Boot except by resetting the CPU. |
| "RAMDisk Images" are more or less just data blocks, and their |
| parameters (address, size) are passed to an OS kernel that is |
| being started. |
| "Multi-File Images" contain several images, typically an OS |
| (Linux) kernel image and one or more data images like |
| RAMDisks. This construct is useful for instance when you want |
| to boot over the network using BOOTP etc., where the boot |
| server provides just a single image file, but you want to get |
| for instance an OS kernel and a RAMDisk image. |
| |
| "Multi-File Images" start with a list of image sizes, each |
| image size (in bytes) specified by an "uint32_t" in network |
| byte order. This list is terminated by an "(uint32_t)0". |
| Immediately after the terminating 0 follow the images, one by |
| one, all aligned on "uint32_t" boundaries (size rounded up to |
| a multiple of 4 bytes). |
| |
| "Firmware Images" are binary images containing firmware (like |
| U-Boot or FPGA images) which usually will be programmed to |
| flash memory. |
| |
| "Script files" are command sequences that will be executed by |
| U-Boot's command interpreter; this feature is especially |
| useful when you configure U-Boot to use a real shell (hush) |
| as command interpreter. |
| |
| |
| Standalone HOWTO: |
| ================= |
| |
| One of the features of U-Boot is that you can dynamically load and |
| run "standalone" applications, which can use some resources of |
| U-Boot like console I/O functions or interrupt services. |
| |
| Two simple examples are included with the sources: |
| |
| "Hello World" Demo: |
| ------------------- |
| |
| 'examples/hello_world.c' contains a small "Hello World" Demo |
| application; it is automatically compiled when you build U-Boot. |
| It's configured to run at address 0x00040004, so you can play with it |
| like that: |
| |
| => loads |
| ## Ready for S-Record download ... |
| ~>examples/hello_world.srec |
| 1 2 3 4 5 6 7 8 9 10 11 ... |
| [file transfer complete] |
| [connected] |
| ## Start Addr = 0x00040004 |
| |
| => go 40004 Hello World! This is a test. |
| ## Starting application at 0x00040004 ... |
| Hello World |
| argc = 7 |
| argv[0] = "40004" |
| argv[1] = "Hello" |
| argv[2] = "World!" |
| argv[3] = "This" |
| argv[4] = "is" |
| argv[5] = "a" |
| argv[6] = "test." |
| argv[7] = "<NULL>" |
| Hit any key to exit ... |
| |
| ## Application terminated, rc = 0x0 |
| |
| Another example, which demonstrates how to register a CPM interrupt |
| handler with the U-Boot code, can be found in 'examples/timer.c'. |
| Here, a CPM timer is set up to generate an interrupt every second. |
| The interrupt service routine is trivial, just printing a '.' |
| character, but this is just a demo program. The application can be |
| controlled by the following keys: |
| |
| ? - print current values og the CPM Timer registers |
| b - enable interrupts and start timer |
| e - stop timer and disable interrupts |
| q - quit application |
| |
| => loads |
| ## Ready for S-Record download ... |
| ~>examples/timer.srec |
| 1 2 3 4 5 6 7 8 9 10 11 ... |
| [file transfer complete] |
| [connected] |
| ## Start Addr = 0x00040004 |
| |
| => go 40004 |
| ## Starting application at 0x00040004 ... |
| TIMERS=0xfff00980 |
| Using timer 1 |
| tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 |
| |
| Hit 'b': |
| [q, b, e, ?] Set interval 1000000 us |
| Enabling timer |
| Hit '?': |
| [q, b, e, ?] ........ |
| tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 |
| Hit '?': |
| [q, b, e, ?] . |
| tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 |
| Hit '?': |
| [q, b, e, ?] . |
| tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 |
| Hit '?': |
| [q, b, e, ?] . |
| tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 |
| Hit 'e': |
| [q, b, e, ?] ...Stopping timer |
| Hit 'q': |
| [q, b, e, ?] ## Application terminated, rc = 0x0 |
| |
| |
| NetBSD Notes: |
| ============= |
| |
| Starting at version 0.9.2, U-Boot supports NetBSD both as host |
| (build U-Boot) and target system (boots NetBSD/mpc8xx). |
| |
| Building requires a cross environment; it is known to work on |
| NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also |
| need gmake since the Makefiles are not compatible with BSD make). |
| Note that the cross-powerpc package does not install include files; |
| attempting to build U-Boot will fail because <machine/ansi.h> is |
| missing. This file has to be installed and patched manually: |
| |
| # cd /usr/pkg/cross/powerpc-netbsd/include |
| # mkdir powerpc |
| # ln -s powerpc machine |
| # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h |
| # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST |
| |
| Native builds *don't* work due to incompatibilities between native |
| and U-Boot include files. |
| |
| Booting assumes that (the first part of) the image booted is a |
| stage-2 loader which in turn loads and then invokes the kernel |
| proper. Loader sources will eventually appear in the NetBSD source |
| tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the |
| meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for |
| details. |
| |
| |
| Implementation Internals: |
| ========================= |
| |
| The following is not intended to be a complete description of every |
| implementation detail. However, it should help to understand the |
| inner workings of U-Boot and make it easier to port it to custom |
| hardware. |
| |
| |
| Initial Stack, Global Data: |
| --------------------------- |
| |
| The implementation of U-Boot is complicated by the fact that U-Boot |
| starts running out of ROM (flash memory), usually without access to |
| system RAM (because the memory controller is not initialized yet). |
| This means that we don't have writable Data or BSS segments, and BSS |
| is not initialized as zero. To be able to get a C environment working |
| at all, we have to allocate at least a minimal stack. Implementation |
| options for this are defined and restricted by the CPU used: Some CPU |
| models provide on-chip memory (like the IMMR area on MPC8xx and |
| MPC826x processors), on others (parts of) the data cache can be |
| locked as (mis-) used as memory, etc. |
| |
| Chris Hallinan posted a good summy of these issues to the |
| u-boot-users mailing list: |
| |
| Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? |
| From: "Chris Hallinan" <clh@net1plus.com> |
| Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) |
| ... |
| |
| Correct me if I'm wrong, folks, but the way I understand it |
| is this: Using DCACHE as initial RAM for Stack, etc, does not |
| require any physical RAM backing up the cache. The cleverness |
| is that the cache is being used as a temporary supply of |
| necessary storage before the SDRAM controller is setup. It's |
| beyond the scope of this list to expain the details, but you |
| can see how this works by studying the cache architecture and |
| operation in the architecture and processor-specific manuals. |
| |
| OCM is On Chip Memory, which I believe the 405GP has 4K. It |
| is another option for the system designer to use as an |
| initial stack/ram area prior to SDRAM being available. Either |
| option should work for you. Using CS 4 should be fine if your |
| board designers haven't used it for something that would |
| cause you grief during the initial boot! It is frequently not |
| used. |
| |
| CFG_INIT_RAM_ADDR should be somewhere that won't interfere |
| with your processor/board/system design. The default value |
| you will find in any recent u-boot distribution in |
| Walnut405.h should work for you. I'd set it to a value larger |
| than your SDRAM module. If you have a 64MB SDRAM module, set |
| it above 400_0000. Just make sure your board has no resources |
| that are supposed to respond to that address! That code in |
| start.S has been around a while and should work as is when |
| you get the config right. |
| |
| -Chris Hallinan |
| DS4.COM, Inc. |
| |
| It is essential to remember this, since it has some impact on the C |
| code for the initialization procedures: |
| |
| * Initialized global data (data segment) is read-only. Do not attempt |
| to write it. |
| |
| * Do not use any unitialized global data (or implicitely initialized |
| as zero data - BSS segment) at all - this is undefined, initiali- |
| zation is performed later (when relocationg to RAM). |
| |
| * Stack space is very limited. Avoid big data buffers or things like |
| that. |
| |
| Having only the stack as writable memory limits means we cannot use |
| normal global data to share information beween the code. But it |
| turned out that the implementation of U-Boot can be greatly |
| simplified by making a global data structure (gd_t) available to all |
| functions. We could pass a pointer to this data as argument to _all_ |
| functions, but this would bloat the code. Instead we use a feature of |
| the GCC compiler (Global Register Variables) to share the data: we |
| place a pointer (gd) to the global data into a register which we |
| reserve for this purpose. |
| |
| When chosing a register for such a purpose we are restricted by the |
| relevant (E)ABI specifications for the current architecture, and by |
| GCC's implementation. |
| |
| For PowerPC, the following registers have specific use: |
| R1: stack pointer |
| R2: TOC pointer |
| R3-R4: parameter passing and return values |
| R5-R10: parameter passing |
| R13: small data area pointer |
| R30: GOT pointer |
| R31: frame pointer |
| |
| (U-Boot also uses R14 as internal GOT pointer.) |
| |
| ==> U-Boot will use R29 to hold a pointer to the global data |
| |
| Note: on PPC, we could use a static initializer (since the |
| address of the global data structure is known at compile time), |
| but it turned out that reserving a register results in somewhat |
| smaller code - although the code savings are not that big (on |
| average for all boards 752 bytes for the whole U-Boot image, |
| 624 text + 127 data). |
| |
| On ARM, the following registers are used: |
| |
| R0: function argument word/integer result |
| R1-R3: function argument word |
| R9: GOT pointer |
| R10: stack limit (used only if stack checking if enabled) |
| R11: argument (frame) pointer |
| R12: temporary workspace |
| R13: stack pointer |
| R14: link register |
| R15: program counter |
| |
| ==> U-Boot will use R8 to hold a pointer to the global data |
| |
| |
| |
| Memory Management: |
| ------------------ |
| |
| U-Boot runs in system state and uses physical addresses, i.e. the |
| MMU is not used either for address mapping nor for memory protection. |
| |
| The available memory is mapped to fixed addresses using the memory |
| controller. In this process, a contiguous block is formed for each |
| memory type (Flash, SDRAM, SRAM), even when it consists of several |
| physical memory banks. |
| |
| U-Boot is installed in the first 128 kB of the first Flash bank (on |
| TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After |
| booting and sizing and initializing DRAM, the code relocates itself |
| to the upper end of DRAM. Immediately below the U-Boot code some |
| memory is reserved for use by malloc() [see CFG_MALLOC_LEN |
| configuration setting]. Below that, a structure with global Board |
| Info data is placed, followed by the stack (growing downward). |
| |
| Additionally, some exception handler code is copied to the low 8 kB |
| of DRAM (0x00000000 ... 0x00001FFF). |
| |
| So a typical memory configuration with 16 MB of DRAM could look like |
| this: |
| |
| 0x0000 0000 Exception Vector code |
| : |
| 0x0000 1FFF |
| 0x0000 2000 Free for Application Use |
| : |
| : |
| |
| : |
| : |
| 0x00FB FF20 Monitor Stack (Growing downward) |
| 0x00FB FFAC Board Info Data and permanent copy of global data |
| 0x00FC 0000 Malloc Arena |
| : |
| 0x00FD FFFF |
| 0x00FE 0000 RAM Copy of Monitor Code |
| ... eventually: LCD or video framebuffer |
| ... eventually: pRAM (Protected RAM - unchanged by reset) |
| 0x00FF FFFF [End of RAM] |
| |
| |
| System Initialization: |
| ---------------------- |
| |
| In the reset configuration, U-Boot starts at the reset entry point |
| (on most PowerPC systens at address 0x00000100). Because of the reset |
| configuration for CS0# this is a mirror of the onboard Flash memory. |
| To be able to re-map memory U-Boot then jumps to it's link address. |
| To be able to implement the initialization code in C, a (small!) |
| initial stack is set up in the internal Dual Ported RAM (in case CPUs |
| which provide such a feature like MPC8xx or MPC8260), or in a locked |
| part of the data cache. After that, U-Boot initializes the CPU core, |
| the caches and the SIU. |
| |
| Next, all (potentially) available memory banks are mapped using a |
| preliminary mapping. For example, we put them on 512 MB boundaries |
| (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash |
| on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is |
| programmed for SDRAM access. Using the temporary configuration, a |
| simple memory test is run that determines the size of the SDRAM |
| banks. |
| |
| When there is more than one SDRAM bank, and the banks are of |
| different size, the larger is mapped first. For equal size, the first |
| bank (CS2#) is mapped first. The first mapping is always for address |
| 0x00000000, with any additional banks following immediately to create |
| contiguous memory starting from 0. |
| |
| Then, the monitor installs itself at the upper end of the SDRAM area |
| and allocates memory for use by malloc() and for the global Board |
| Info data; also, the exception vector code is copied to the low RAM |
| pages, and the final stack is set up. |
| |
| Only after this relocation will you have a "normal" C environment; |
| until that you are restricted in several ways, mostly because you are |
| running from ROM, and because the code will have to be relocated to a |
| new address in RAM. |
| |
| |
| U-Boot Porting Guide: |
| ---------------------- |
| |
| [Based on messages by Jerry Van Baren in the U-Boot-Users mailing |
| list, October 2002] |
| |
| |
| int main (int argc, char *argv[]) |
| { |
| sighandler_t no_more_time; |
| |
| signal (SIGALRM, no_more_time); |
| alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); |
| |
| if (available_money > available_manpower) { |
| pay consultant to port U-Boot; |
| return 0; |
| } |
| |
| Download latest U-Boot source; |
| |
| Subscribe to u-boot-users mailing list; |
| |
| if (clueless) { |
| email ("Hi, I am new to U-Boot, how do I get started?"); |
| } |
| |
| while (learning) { |
| Read the README file in the top level directory; |
| Read http://www.denx.de/re/DPLG.html |
| Read the source, Luke; |
| } |
| |
| if (available_money > toLocalCurrency ($2500)) { |
| Buy a BDI2000; |
| } else { |
| Add a lot of aggravation and time; |
| } |
| |
| Create your own board support subdirectory; |
| |
| Create your own board config file; |
| |
| while (!running) { |
| do { |
| Add / modify source code; |
| } until (compiles); |
| Debug; |
| if (clueless) |
| email ("Hi, I am having problems..."); |
| } |
| Send patch file to Wolfgang; |
| |
| return 0; |
| } |
| |
| void no_more_time (int sig) |
| { |
| hire_a_guru(); |
| } |
| |
| |
| |
| Coding Standards: |
| ----------------- |
| |
| All contributions to U-Boot should conform to the Linux kernel |
| coding style; see the file "Documentation/CodingStyle" in your Linux |
| kernel source directory. |
| |
| Please note that U-Boot is implemented in C (and to some small parts |
| in Assembler); no C++ is used, so please do not use C++ style |
| comments (//) in your code. |
| |
| Submissions which do not conform to the standards may be returned |
| with a request to reformat the changes. |
| |
| |
| Submitting Patches: |
| ------------------- |
| |
| Since the number of patches for U-Boot is growing, we need to |
| establish some rules. Submissions which do not conform to these rules |
| may be rejected, even when they contain important and valuable stuff. |
| |
| |
| When you send a patch, please include the following information with |
| it: |
| |
| * For bug fixes: a description of the bug and how your patch fixes |
| this bug. Please try to include a way of demonstrating that the |
| patch actually fixes something. |
| |
| * For new features: a description of the feature and your |
| implementation. |
| |
| * A CHANGELOG entry as plaintext (separate from the patch) |
| |
| * For major contributions, your entry to the CREDITS file |
| |
| * When you add support for a new board, don't forget to add this |
| board to the MAKEALL script, too. |
| |
| * If your patch adds new configuration options, don't forget to |
| document these in the README file. |
| |
| * The patch itself. If you are accessing the CVS repository use "cvs |
| update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your |
| version of diff does not support these options, then get the latest |
| version of GNU diff. |
| |
| We accept patches as plain text, MIME attachments or as uuencoded |
| gzipped text. |
| |
| Notes: |
| |
| * Before sending the patch, run the MAKEALL script on your patched |
| source tree and make sure that no errors or warnings are reported |
| for any of the boards. |
| |
| * Keep your modifications to the necessary minimum: A patch |
| containing several unrelated changes or arbitrary reformats will be |
| returned with a request to re-formatting / split it. |
| |
| * If you modify existing code, make sure that your new code does not |
| add to the memory footprint of the code ;-) Small is beautiful! |
| When adding new features, these should compile conditionally only |
| (using #ifdef), and the resulting code with the new feature |
| disabled must not need more memory than the old code without your |
| modification. |