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bn_nc_u-boot

Bn_nc_u-boot is a project mainly written in C and ASSEMBLY, based on the View license.

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(C) Copyright 2000 - 2005

Wolfgang Denk, DENX Software Engineering, [email protected].

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See file CREDITS for list of people who contributed to this

project.

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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.

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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.

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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

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Summary:

This directory contains the source code for U-Boot, a boot loader for Embedded boards based on PowerPC, ARM, MIPS and several other 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 [email protected]. 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 dependent files
  • common Misc architecture independent functions
  • cpu CPU specific files
    • 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
    • arm720t Files specific to ARM 720 CPUs
    • arm920t Files specific to ARM 920 CPUs
    • at91rm9200 Files specific to Atmel AT91RM9200 CPU
    • imx Files specific to Freescale MC9328 i.MX CPUs
    • s3c24x0 Files specific to Samsung S3C24X0 CPUs
    • arm925t Files specific to ARM 925 CPUs
    • arm926ejs Files specific to ARM 926 CPUs
    • arm1136 Files specific to ARM 1136 CPUs
    • i386 Files specific to i386 CPUs
    • ixp Files specific to Intel XScale IXP CPUs
    • mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
    • mips Files specific to MIPS CPUs
    • mpc5xx Files specific to Freescale MPC5xx CPUs
    • mpc5xxx Files specific to Freescale MPC5xxx CPUs
    • mpc8xx Files specific to Freescale MPC8xx CPUs
    • mpc8220 Files specific to Freescale MPC8220 CPUs
    • mpc824x Files specific to Freescale MPC824x CPUs
    • mpc8260 Files specific to Freescale MPC8260 CPUs
    • mpc85xx Files specific to Freescale MPC85xx CPUs
    • nios Files specific to Altera NIOS CPUs
    • nios2 Files specific to Altera Nios-II CPUs
    • ppc4xx Files specific to AMCC PowerPC 4xx CPUs
    • pxa Files specific to Intel XScale PXA CPUs
    • s3c44b0 Files specific to Samsung S3C44B0 CPUs
    • sa1100 Files specific to Intel StrongARM SA1100 CPUs
  • disk Code for disk drive partition handling
  • doc Documentation (don't expect too much)
  • drivers Commonly used device drivers
  • dtt Digital Thermometer and Thermostat drivers
  • examples Example code for standalone applications, etc.
  • include Header Files
  • lib_arm Files generic to ARM architecture
  • lib_generic Files generic to all architectures
  • lib_i386 Files generic to i386 architecture
  • lib_m68k Files generic to m68k architecture
  • lib_mips Files generic to MIPS architecture
  • lib_nios Files generic to NIOS architecture
  • lib_ppc Files generic to PowerPC architecture
  • net Networking code
  • post Power On Self Test
  • rtc Real Time Clock drivers
  • tools Tools to build S-Record or U-Boot images, etc.

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 _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/.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_MPC5xx or CONFIG_MPC8220 or CONFIG_MPC824X, CONFIG_MPC8260 or CONFIG_MPC85xx or CONFIG_IOP480 or CONFIG_405GP or CONFIG_405EP or CONFIG_440 or CONFIG_MPC74xx or CONFIG_750FX

    ARM based CPUs:
    ---------------
    CONFIG_SA1110
    CONFIG_ARM7
    CONFIG_PXA250
    CONFIG_CPU_MONAHANS
    
    MicroBlaze based CPUs:
    ----------------------
    CONFIG_MICROBLAZE
    
    Nios-2 based CPUs:
    ----------------------
    CONFIG_NIOS2
  • Board Type: Define exactly one of

    PowerPC based boards:
    ---------------------
    
    CONFIG_ADCIOP       CONFIG_FPS860L      CONFIG_OXC
    CONFIG_ADS860       CONFIG_GEN860T      CONFIG_PCI405
    CONFIG_AMX860       CONFIG_GENIETV      CONFIG_PCIPPC2
    CONFIG_AP1000       CONFIG_GTH      CONFIG_PCIPPC6
    CONFIG_AR405        CONFIG_gw8260       CONFIG_pcu_e
    CONFIG_BAB7xx       CONFIG_hermes       CONFIG_PIP405
    CONFIG_BC3450       CONFIG_hymod        CONFIG_PM826
    CONFIG_c2mon        CONFIG_IAD210       CONFIG_ppmc8260
    CONFIG_CANBT        CONFIG_ICU862       CONFIG_QS823
    CONFIG_CCM      CONFIG_IP860        CONFIG_QS850
    CONFIG_CMI      CONFIG_IPHASE4539   CONFIG_QS860T
    CONFIG_cogent_mpc8260   CONFIG_IVML24       CONFIG_RBC823
    CONFIG_cogent_mpc8xx    CONFIG_IVML24_128   CONFIG_RPXClassic
    CONFIG_CPCI405      CONFIG_IVML24_256   CONFIG_RPXlite
    CONFIG_CPCI4052     CONFIG_IVMS8        CONFIG_RPXsuper
    CONFIG_CPCIISER4    CONFIG_IVMS8_128    CONFIG_rsdproto
    CONFIG_CPU86        CONFIG_IVMS8_256    CONFIG_sacsng
    CONFIG_CRAYL1       CONFIG_JSE      CONFIG_Sandpoint8240
    CONFIG_CSB272       CONFIG_LANTEC       CONFIG_Sandpoint8245
    CONFIG_CU824        CONFIG_LITE5200B    CONFIG_sbc8260
    CONFIG_DASA_SIM     CONFIG_lwmon        CONFIG_sbc8560
    CONFIG_DB64360      CONFIG_MBX      CONFIG_SM850
    CONFIG_DB64460      CONFIG_MBX860T      CONFIG_SPD823TS
    CONFIG_DU405        CONFIG_MHPC     CONFIG_STXGP3
    CONFIG_DUET_ADS     CONFIG_MIP405       CONFIG_SXNI855T
    CONFIG_EBONY        CONFIG_MOUSSE       CONFIG_TQM823L
    CONFIG_ELPPC        CONFIG_MPC8260ADS   CONFIG_TQM8260
    CONFIG_ELPT860      CONFIG_MPC8540ADS   CONFIG_TQM850L
    CONFIG_ep8260       CONFIG_MPC8540EVAL  CONFIG_TQM855L
    CONFIG_ERIC     CONFIG_MPC8560ADS   CONFIG_TQM860L
    CONFIG_ESTEEM192E   CONFIG_MUSENKI      CONFIG_TTTech
    CONFIG_ETX094       CONFIG_MVS1     CONFIG_UTX8245
    CONFIG_EVB64260     CONFIG_NETPHONE     CONFIG_V37
    CONFIG_FADS823      CONFIG_NETTA        CONFIG_W7OLMC
    CONFIG_FADS850SAR   CONFIG_NETVIA       CONFIG_W7OLMG
    CONFIG_FADS860T     CONFIG_NX823        CONFIG_WALNUT
    CONFIG_FLAGADM      CONFIG_OCRTC        CONFIG_ZPC1900
    CONFIG_FPS850L      CONFIG_ORSG     CONFIG_ZUMA
    
    ARM based boards:
    -----------------
    
    CONFIG_ARMADILLO,   CONFIG_AT91RM9200DK,    CONFIG_CERF250,
    CONFIG_CSB637,      CONFIG_DELTA,       CONFIG_DNP1110,
    CONFIG_EP7312,      CONFIG_H2_OMAP1610, CONFIG_HHP_CRADLE,
    CONFIG_IMPA7,       CONFIG_INNOVATOROMAP1510,   CONFIG_INNOVATOROMAP1610,
    CONFIG_KB9202,      CONFIG_LART,        CONFIG_LPD7A400,
    CONFIG_LUBBOCK,     CONFIG_OSK_OMAP5912,    CONFIG_OMAP2420H4,
    CONFIG_PLEB2,       CONFIG_SHANNON,     CONFIG_P2_OMAP730,
    CONFIG_SMDK2400,    CONFIG_SMDK2410,    CONFIG_TRAB,
    CONFIG_VCMA9
    
    MicroBlaze based boards:
    ------------------------
    
    CONFIG_SUZAKU
    
    Nios-2 based boards:
    ------------------------
    
    CONFIG_PCI5441 CONFIG_PK1C20
    CONFIG_EP1C20 CONFIG_EP1S10 CONFIG_EP1S40
  • 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" |-/|-/

  • Board flavour: (if CONFIG_MPC8260ADS is defined) CONFIG_ADSTYPE Possible values are: CFG_8260ADS - original MPC8260ADS CFG_8266ADS - MPC8266ADS CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR CFG_8272ADS - MPC8272ADS

  • MPC824X Family Member (if CONFIG_MPC824X is defined) Define exactly one of CONFIG_MPC8240, CONFIG_MPC8245

  • 8xx CPU Options: (if using an MPC8xx cpu) CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if get_gclk_freq() cannot work e.g. if there is no 32KHz reference PIT/RTC clock CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK or XTAL/EXTAL)

  • 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): CFG_8xx_CPUCLK_MIN CFG_8xx_CPUCLK_MAX CONFIG_8xx_CPUCLK_DEFAULT See doc/README.MPC866

    CFG_MEASURE_CPUCLK
    
    Define this to measure the actual CPU clock instead
    of relying on the correctness of the configured
    values. Mostly useful for board bringup to make sure
    the PLL is locked at the intended frequency. Note
    that this requires a (stable) reference clock (32 kHz
    RTC clock or CFG_8XX_XIN)
  • Intel Monahans options: CFG_MONAHANS_RUN_MODE_OSC_RATIO

    Defines the Monahans run mode to oscillator
    ratio. Valid values are 8, 16, 24, 31. The core
    frequency is this value multiplied by 13 MHz.
    
    CFG_MONAHANS_TURBO_RUN_MODE_RATIO
    
    Defines the Monahans turbo mode to oscillator
    ratio. Valid values are 1 (default if undefined) and
    2. The core frequency as calculated above is multiplied
    by this value.
  • Linux Kernel 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.
    
    CONFIG_MEMSIZE_IN_BYTES     [relevant for MIPS only]
    
    When transfering memsize parameter to linux, some versions
    expect it to be in bytes, others in MB.
    Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
    
    CONFIG_OF_FLAT_TREE
    
    New kernel versions are expecting firmware settings to be
    passed using flat open firmware trees.
    The environment variable "disable_of", when set, disables this
    functionality.
    
    CONFIG_OF_FLAT_TREE_MAX_SIZE
    
    The maximum size of the constructed OF tree.
    
    OF_CPU - The proper name of the cpus node.
    OF_SOC - The proper name of the soc node.
    OF_TBCLK - The timebase frequency.
    OF_STDOUT_PATH - The path to the console device
    
    CONFIG_OF_HAS_BD_T
    
    The resulting flat device tree will have a copy of the bd_t.
    Space should be pre-allocated in the dts for the bd_t.
    
    CONFIG_OF_HAS_UBOOT_ENV
    
    The resulting flat device tree will have a copy of u-boot's
    environment variables
    
    CONFIG_OF_BOARD_SETUP
    
    Board code has addition modification that it wants to make
    to the flat device tree before handing it off to the kernel
  • Serial Ports: CFG_PL010_SERIAL

    Define this if you want support for Amba PrimeCell PL010 UARTs.
    
    CFG_PL011_SERIAL
    
    Define this if you want support for Amba PrimeCell PL011 UARTs.
    
    CONFIG_PL011_CLOCK
    
    If you have Amba PrimeCell PL011 UARTs, set this variable to
    the clock speed of the UARTs.
    
    CONFIG_PL01x_PORTS
    
    If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
    define this to a list of base addresses for each (supported)
    port. See e.g. include/configs/versatile.h
  • 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'.
    
    When CONFIG_SILENT_CONSOLE is defined, all console
    messages (by U-Boot and Linux!) can be silenced with
    the "silent" environment variable. See
    doc/README.silent for more information.
  • Console Baudrate: CONFIG_BAUDRATE - in bps Select one of the baudrates listed in CFG_BAUDRATE_TABLE, see below. CFG_BRGCLK_PRESCALE, baudrate prescale

  • 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.
    
    Leave undefined to disable this feature, including
    disable the buffer and hardware handshake.
  • Console UART Number: CONFIG_UART1_CONSOLE

    AMCC PPC4xx only.
    If defined internal UART1 (and not UART0) is used
    as default U-Boot console.
  • 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_AUTOSCRIPT Autoscript Support
    CFG_CMD_BDI   bdinfo
    CFG_CMD_BEDBUG  * Include BedBug Debugger
    CFG_CMD_BMP * BMP support
    CFG_CMD_BSP * Board specific commands
    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_DIAG    * Diagnostics
    CFG_CMD_DOC * Disk-On-Chip Support
    CFG_CMD_DTT * Digital Therm and Thermostat
    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_FAT * FAT partition support
    CFG_CMD_FDOS    * Dos diskette Support
    CFG_CMD_FLASH     flinfo, erase, protect
    CFG_CMD_FPGA      FPGA device initialization support
    CFG_CMD_HWFLOW  * RTS/CTS hw flow control
    CFG_CMD_I2C * I2C serial bus support
    CFG_CMD_IDE * IDE harddisk support
    CFG_CMD_IMI   iminfo
    CFG_CMD_IMLS      List all found images
    CFG_CMD_IMMAP   * IMMR dump support
    CFG_CMD_IRQ * irqinfo
    CFG_CMD_ITEST     Integer/string test of 2 values
    CFG_CMD_JFFS2   * JFFS2 Support
    CFG_CMD_KGDB    * kgdb
    CFG_CMD_LOADB     loadb
    CFG_CMD_LOADS     loads
    CFG_CMD_MEMORY    md, mm, nm, mw, cp, cmp, crc, base,
              loop, loopw, mtest
    CFG_CMD_MISC      Misc functions like sleep etc
    CFG_CMD_MMC * MMC memory mapped support
    CFG_CMD_MII * MII utility commands
    CFG_CMD_NAND    * NAND support
    CFG_CMD_NET   bootp, tftpboot, rarpboot
    CFG_CMD_PCI * pciinfo
    CFG_CMD_PCMCIA  * PCMCIA support
    CFG_CMD_PING    * send ICMP ECHO_REQUEST to network host
    CFG_CMD_PORTIO  * Port I/O
    CFG_CMD_REGINFO * Register dump
    CFG_CMD_RUN   run command in env variable
    CFG_CMD_SAVES   * save S record dump
    CFG_CMD_SCSI    * SCSI Support
    CFG_CMD_SDRAM   * print SDRAM configuration information
              (requires CFG_CMD_I2C)
    CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
    CFG_CMD_SPI * SPI serial bus support
    CFG_CMD_USB * USB support
    CFG_CMD_VFD * VFD support (TRAB)
    CFG_CMD_BSP * Board SPecific functions
    CFG_CMD_CDP * Cisco Discover Protocol support
    -----------------------------------------------
    CFG_CMD_ALL all
    
    CONFIG_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
    CONFIG_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 be 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.

  • U-Boot Version: CONFIG_VERSION_VARIABLE If this variable is defined, an environment variable named "ver" is created by U-Boot showing the U-Boot version as printed by the "version" command. This variable is readonly.

  • 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_DS1307   - use Maxim, Inc. DS1307 RTC
    CONFIG_RTC_DS1337   - use Maxim, Inc. DS1337 RTC
    CONFIG_RTC_DS1338   - use Maxim, Inc. DS1338 RTC
    CONFIG_RTC_DS164x   - use Dallas DS164x RTC
    CONFIG_RTC_MAX6900  - use Maxim, Inc. MAX6900 RTC
    
    Note that if the RTC uses I2C, then the I2C interface
    must also be configured. See I2C Support, below.
  • 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 - this is defined in several board configurations files but used nowhere!

    CONFIG_IDE_RESET - is this is defined, IDE Reset will
    be performed by calling the function
        ide_set_reset(int reset)
    which has to be defined in a board specific file
  • ATAPI Support: CONFIG_ATAPI

    Set this to enable ATAPI support.
  • LBA48 Support CONFIG_LBA48

    Set this to enable support for disks larger than 137GB
    Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
    Whithout these , LBA48 support uses 32bit variables and will 'only'
    support disks up to 2.1TB.
    
    CFG_64BIT_LBA:
        When enabled, makes the IDE subsystem use 64bit sector addresses.
        Default is 32bit.
  • 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_E1000 Support for Intel 8254x gigabit chips.

    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.
  • NETWORK Support (other):

    CONFIG_DRIVER_LAN91C96
    Support for SMSC's LAN91C96 chips.
    
        CONFIG_LAN91C96_BASE
        Define this to hold the physical address
        of the LAN91C96's I/O space
    
        CONFIG_LAN91C96_USE_32_BIT
        Define this to enable 32 bit addressing
    
    CONFIG_DRIVER_SMC91111
    Support for SMSC's LAN91C111 chip
    
        CONFIG_SMC91111_BASE
        Define this to hold the physical address
        of the device (I/O space)
    
        CONFIG_SMC_USE_32_BIT
        Define this if data bus is 32 bits
    
        CONFIG_SMC_USE_IOFUNCS
        Define this to use i/o functions instead of macros
        (some hardware wont work with macros)
  • USB Support: At the moment only the UHCI host controller is supported (PIP405, MIP405, MPC5200); define CONFIG_USB_UHCI to enable it. define CONFIG_USB_KEYBOARD to enable the USB Keyboard and define CONFIG_USB_STORAGE to enable the USB storage devices. Note: Supported are USB Keyboards and USB Floppy drives (TEAC FD-05PUB). MPC5200 USB requires additional defines: CONFIG_USB_CLOCK for 528 MHz Clock: 0x0001bbbb CONFIG_USB_CONFIG for differential drivers: 0x00001000 for single ended drivers: 0x00005000

  • MMC Support: The MMC controller on the Intel PXA is supported. To enable this define CONFIG_MMC. The MMC can be accessed from the boot prompt by mapping the device to physical memory similar to flash. Command line is enabled with CFG_CMD_MMC. The MMC driver also works with the FAT fs. This is enabled with CFG_CMD_FAT.

  • Journaling Flash filesystem support: CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE, CONFIG_JFFS2_NAND_DEV Define these for a default partition on a NAND device

    CFG_JFFS2_FIRST_SECTOR,
    CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS
    Define these for a default partition on a NOR device
    
    CFG_JFFS_CUSTOM_PART
    Define this to create an own partition. You have to provide a
    function struct part_info* jffs2_part_info(int part_num)
    
    If you define only one JFFS2 partition you may also want to
    #define CFG_JFFS_SINGLE_PART    1
    to disable the command chpart. This is the default when you
    have not defined a custom partition
  • 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. The
    video output is selected via environment 'videoout'
    (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
    assumed.
    
    For the CT69000 and SMI_LYNXEM drivers, videomode is
    selected via environment 'videomode'. Two diferent ways
    are possible:
    - "videomode=num"   'num' is a standard LiLo mode numbers.
    Following standard modes are supported  (* is default):
    
          Colors    640x480 800x600 1024x768 1152x864 1280x1024
    -------------+---------------------------------------------
          8 bits |  0x301*  0x303    0x305    0x161     0x307
         15 bits |  0x310   0x313    0x316    0x162     0x319
         16 bits |  0x311   0x314    0x317    0x163     0x31A
         24 bits |  0x312   0x315    0x318      ?       0x31B
    -------------+---------------------------------------------
    (i.e. setenv videomode 317; saveenv; reset;)
    
    - "videomode=bootargs" all the video parameters are parsed
    from the bootargs. (See drivers/videomodes.c)
    
    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
  • Keyboard Support: CONFIG_KEYBOARD

    Define this to enable a custom keyboard support.
    This simply calls drv_keyboard_init() which must be
    defined in your board-specific files.
    The only board using this so far is RBC823.
  • 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_NL6448AC33:
    
        NEC NL6448AC33-18. Active, color, single scan.
    
    CONFIG_NEC_NL6448BC20
    
        NEC NL6448BC20-08. 6.5", 640x480.
        Active, color, single scan.
    
    CONFIG_NEC_NL6448BC33_54
    
        NEC NL6448BC33-54. 10.4", 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.
  • Splash Screen Support: CONFIG_SPLASH_SCREEN

    If this option is set, the environment is checked for
    a variable "splashimage". If found, the usual display
    of logo, copyright and system information on the LCD
    is suppressed and the BMP image at the address
    specified in "splashimage" is loaded instead. The
    console is redirected to the "nulldev", too. This
    allows for a "silent" boot where a splash screen is
    loaded very quickly after power-on.
  • Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP

    If this option is set, additionally to standard BMP
    images, gzipped BMP images can be displayed via the
    splashscreen support or the bmp command.
  • Compression support: CONFIG_BZIP2

    If this option is set, support for bzip2 compressed
    images is included. If not, only uncompressed and gzip
    compressed images are supported.
    
    NOTE: the bzip2 algorithm requires a lot of RAM, so
    the malloc area (as defined by CFG_MALLOC_LEN) should
    be at least 4MB.
  • MII/PHY support: CONFIG_PHY_ADDR

    The address of PHY on MII bus.
    
    CONFIG_PHY_CLOCK_FREQ (ppc4xx)
    
    The clock frequency of the MII bus
    
    CONFIG_PHY_GIGE
    
    If this option is set, support for speed/duplex
    detection of Gigabit PHY is included.
    
    CONFIG_PHY_RESET_DELAY
    
    Some PHY like Intel LXT971A need extra delay after
    reset before any MII register access is possible.
    For such PHY, set this option to the usec delay
    required. (minimum 300usec for LXT971A)
    
    CONFIG_PHY_CMD_DELAY (ppc4xx)
    
    Some PHY like Intel LXT971A need extra delay after
    command issued before MII status register can be read
  • 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
  • DHCP Advanced Options: CONFIG_BOOTP_MASK

    You can fine tune the DHCP functionality by adding
    these flags to the CONFIG_BOOTP_MASK define:
    
    CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
    serverip from a DHCP server, it is possible that more
    than one DNS serverip is offered to the client.
    If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
    serverip will be stored in the additional environment
    variable "dnsip2". The first DNS serverip is always
    stored in the variable "dnsip", when CONFIG_BOOTP_DNS
    is added to the CONFIG_BOOTP_MASK.
    
    CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
    to do a dynamic update of a DNS server. To do this, they
    need the hostname of the DHCP requester.
    If CONFIG_BOOP_SEND_HOSTNAME is added to the
    CONFIG_BOOTP_MASK, the content of the "hostname"
    environment variable is passed as option 12 to
    the DHCP server.
    • CDP Options: CONFIG_CDP_DEVICE_ID

      The device id used in CDP trigger frames.

      CONFIG_CDP_DEVICE_ID_PREFIX

      A two character string which is prefixed to the MAC address of the device.

      CONFIG_CDP_PORT_ID

      A printf format string which contains the ascii name of the port. Normally is set to "eth%d" which sets eth0 for the first ethernet, eth1 for the second etc.

      CONFIG_CDP_CAPABILITIES

      A 32bit integer which indicates the device capabilities; 0x00000010 for a normal host which does not forwards.

      CONFIG_CDP_VERSION

      An ascii string containing the version of the software.

      CONFIG_CDP_PLATFORM

      An ascii string containing the name of the platform.

      CONFIG_CDP_TRIGGER

      A 32bit integer sent on the trigger.

      CONFIG_CDP_POWER_CONSUMPTION

      A 16bit integer containing the power consumption of the device in .1 of milliwatts.

      CONFIG_CDP_APPLIANCE_VLAN_TYPE

      A byte containing the id of the VLAN.

  • 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

    These enable I2C serial bus commands. Defining either of
    (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
    include the appropriate I2C driver for the selected cpu.
    
    This will allow you to use i2c commands at the u-boot
    command line (as long as you set CFG_CMD_I2C in
    CONFIG_COMMANDS) and communicate with i2c based realtime
    clock chips. See 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 configures u-boot to use a software (aka
    bit-banging) driver instead of CPM or similar hardware
    support for I2C.
    
    There are several other quantities that must also be
    defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
    
    In both cases you will need to define CFG_I2C_SPEED
    to be the frequency (in Hz) at which you wish your i2c bus
    to run and CFG_I2C_SLAVE to be the address of this node (ie
    the cpu's i2c node address).
    
    Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
    sets the cpu up as a master node and so its address should
    therefore be cleared to 0 (See, eg, MPC823e User's Manual
    p.16-473). So, set CFG_I2C_SLAVE to 0.
    
    That's all that's required for CONFIG_HARD_I2C.
    
    If you use the software i2c interface (CONFIG_SOFT_I2C)
    then the following macros need to be defined (examples are
    from include/configs/lwmon.h):
    
    I2C_INIT
    
    (Optional). Any commands necessary to enable the I2C
    controller or configure ports.
    
    eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |=  PB_SCL)
    
    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.
    
    eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |=  PB_SDA)
    
    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.
    
    eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
    
    I2C_READ
    
    Code that returns TRUE if the I2C data line is high,
    FALSE if it is low.
    
    eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
    
    I2C_SDA(bit)
    
    If <bit> is TRUE, sets the I2C data line high. If it
    is FALSE, it clears it (low).
    
    eg: #define I2C_SDA(bit) 
        if(bit) immr->im_cpm.cp_pbdat |=  PB_SDA; 
        else    immr->im_cpm.cp_pbdat &= ~PB_SDA
    
    I2C_SCL(bit)
    
    If <bit> is TRUE, sets the I2C clock line high. If it
    is FALSE, it clears it (low).
    
    eg: #define I2C_SCL(bit) 
        if(bit) immr->im_cpm.cp_pbdat |=  PB_SCL; 
        else    immr->im_cpm.cp_pbdat &= ~PB_SCL
    
    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). Often defined to be something
    like:
    
    #define I2C_DELAY  udelay(2)
    
    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.
    
    CONFIG_I2CFAST (PPC405GP|PPC405EP only)
    
    This option enables configuration of bi_iic_fast[] flags
    in u-boot bd_info structure based on u-boot environment
    variable "i2cfast". (see also i2cfast)
  • 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.
  • 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 be 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_AUTO_COMPLETE

    Enable auto completion of commands using TAB.
    
    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 `name=value'. To access a local
    variable later on, you have write `$name' or
    `${name}'; to execute the contents of a variable
    directly type `$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.
  • Commandline Editing and History: CONFIG_CMDLINE_EDITING

    Enable editiong and History functions for interactive
    commandline input operations
  • 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 environment compiled into the boot image.
    
    For example, place something like this in your
    board's config file:
    
    #define CONFIG_EXTRA_ENV_SETTINGS 
        "myvar1=value1" 
        "myvar2=value2"
    
    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, 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.
  • DataFlash Support: CONFIG_HAS_DATAFLASH

    Defining this option enables DataFlash features and
    allows to read/write in Dataflash via the standard
    commands cp, md...
  • SystemACE Support: CONFIG_SYSTEMACE

    Adding this option adds support for Xilinx SystemACE
    chips attached via some sort of local bus. The address
    of the chip must alsh be defined in the
    CFG_SYSTEMACE_BASE macro. For example:
    
    #define CONFIG_SYSTEMACE
    #define CFG_SYSTEMACE_BASE 0xf0000000
    
    When SystemACE support is added, the "ace" device type
    becomes available to the fat commands, i.e. fatls.
  • TFTP Fixed UDP Port: CONFIG_TFTP_PORT

    If this is defined, the environment variable tftpsrcp
    is used to supply the TFTP UDP source port value.
    If tftpsrcp isn't defined, the normal pseudo-random port
    number generator is used.
    
    Also, the environment variable tftpdstp is used to supply
    the TFTP UDP destination port value.  If tftpdstp isn't
    defined, the normal port 69 is used.
    
    The purpose for tftpsrcp is to allow a TFTP server to
    blindly start the TFTP transfer using the pre-configured
    target IP address and UDP port. This has the effect of
    "punching through" the (Windows XP) firewall, allowing
    the remainder of the TFTP transfer to proceed normally.
    A better solution is to properly configure the firewall,
    but sometimes that is not allowed.
  • 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

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