Uboot-2011.6 is a project mainly written in C and ASSEMBLY, based on the View license.
uboot for mini2440
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.
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. The MAINTAINERS file lists board maintainers.
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.denx.de/pipermail/u-boot and http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
The U-Boot source code is maintained in the git repository at git://www.denx.de/git/u-boot.git ; you can browse it online at http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
The "snapshot" links on this page allow you to download tarballs of any version you might be interested in. Official releases are also available for FTP download from the ftp://ftp.denx.de/pub/u-boot/ directory.
Pre-built (and tested) images are available from ftp://ftp.denx.de/pub/u-boot/images/
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_startStarting with the release in October 2008, the names of the releases were changed from numerical release numbers without deeper meaning into a time stamp based numbering. Regular releases are identified by names consisting of the calendar year and month of the release date. Additional fields (if present) indicate release candidates or bug fix releases in "stable" maintenance trees.
Examples: U-Boot v2009.11 - Release November 2009 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
/arch Architecture specific files /arm Files generic to ARM architecture /cpu CPU specific files /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 /ixp Files specific to Intel XScale IXP CPUs /pxa Files specific to Intel XScale PXA CPUs /s3c44b0 Files specific to Samsung S3C44B0 CPUs /sa1100 Files specific to Intel StrongARM SA1100 CPUs /lib Architecture specific library files /avr32 Files generic to AVR32 architecture /cpu CPU specific files /lib Architecture specific library files /blackfin Files generic to Analog Devices Blackfin architecture /cpu CPU specific files /lib Architecture specific library files /x86 Files generic to x86 architecture /cpu CPU specific files /lib Architecture specific library files /m68k Files generic to m68k architecture /cpu CPU specific files /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs /lib Architecture specific library files /microblaze Files generic to microblaze architecture /cpu CPU specific files /lib Architecture specific library files /mips Files generic to MIPS architecture /cpu CPU specific files /lib Architecture specific library files /nios2 Files generic to Altera NIOS2 architecture /cpu CPU specific files /lib Architecture specific library files /powerpc Files generic to PowerPC architecture /cpu CPU specific files /74xx_7xx Files specific to Freescale MPC74xx and 7xx 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 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs /lib Architecture specific library files /sh Files generic to SH architecture /cpu CPU specific files /sh2 Files specific to sh2 CPUs /sh3 Files specific to sh3 CPUs /sh4 Files specific to sh4 CPUs /lib Architecture specific library files /sparc Files generic to SPARC architecture /cpu CPU specific files /leon2 Files specific to Gaisler LEON2 SPARC CPU /leon3 Files specific to Gaisler LEON3 SPARC CPU /lib Architecture specific library files /api Machine/arch independent API for external apps /board Board dependent files /common Misc architecture independent functions /disk Code for disk drive partition handling /doc Documentation (don't expect too much) /drivers Commonly used device drivers /examples Example code for standalone applications, etc. /fs Filesystem code (cramfs, ext2, jffs2, etc.) /include Header Files /lib Files generic to all architectures /libfdt Library files to support flattened device trees /lzma Library files to support LZMA decompression /lzo Library files to support LZO decompression /net Networking code /post Power On Self Test /rtc Real Time Clock drivers /tools Tools to build S-Record or U-Boot images, etc.
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 "CONFIGSYS".
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.
For all supported boards there are ready-to-use default
configurations available; just type "make
Example: For a TQM823L module type:
cd u-boot
make TQM823L_configFor 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 depends on the combination of board and CPU type; all
such information is kept in a configuration file
"include/configs/
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, e.g. CONFIG_MPC85XX.
Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined) Define exactly one, e.g. CONFIG_ATSTK1002
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: CONFIG_SYS_8260ADS - original MPC8260ADS CONFIG_SYS_8266ADS - MPC8266ADS CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR CONFIG_SYS_8272ADS - MPC8272ADS
Marvell Family Member CONFIG_SYS_MVFS - define it if you want to enable multiple fs option at one time for marvell soc family
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): CONFIG_SYS_8xx_CPUCLK_MIN CONFIG_SYS_8xx_CPUCLK_MAX CONFIG_8xx_CPUCLK_DEFAULT See doc/README.MPC866
CONFIG_SYS_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 CONFIG_SYS_8XX_XIN)
CONFIG_SYS_DELAYED_ICACHE
Define this option if you want to enable the
ICache only when Code runs from RAM.85xx CPU Options: CONFIG_SYS_FSL_TBCLK_DIV
Defines the core time base clock divider ratio compared to the
system clock. On most PQ3 devices this is 8, on newer QorIQ
devices it can be 16 or 32. The ratio varies from SoC to Soc.
CONFIG_SYS_FSL_PCIE_COMPAT
Defines the string to utilize when trying to match PCIe device
tree nodes for the given platform.Intel Monahans options: CONFIG_SYS_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.
CONFIG_SYS_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 transferring 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_LIBFDT
New kernel versions are expecting firmware settings to be
passed using flattened device trees (based on open firmware
concepts).
CONFIG_OF_LIBFDT
* New libfdt-based support
* Adds the "fdt" command
* The bootm command automatically updates the fdt
OF_CPU - The proper name of the cpus node (only required for
MPC512X and MPC5xxx based boards).
OF_SOC - The proper name of the soc node (only required for
MPC512X and MPC5xxx based boards).
OF_TBCLK - The timebase frequency.
OF_STDOUT_PATH - The path to the console device
boards with QUICC Engines require OF_QE to set UCC MAC
addresses
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
CONFIG_OF_BOOT_CPU
This define fills in the correct boot CPU in the boot
param header, the default value is zero if undefined.
CONFIG_OF_IDE_FIXUP
U-Boot can detect if an IDE device is present or not.
If not, and this new config option is activated, U-Boot
removes the ATA node from the DTS before booting Linux,
so the Linux IDE driver does not probe the device and
crash. This is needed for buggy hardware (uc101) where
no pull down resistor is connected to the signal IDE5V_DD7.vxWorks boot parameters:
bootvx constructs a valid bootline using the following
environments variables: bootfile, ipaddr, serverip, hostname.
It loads the vxWorks image pointed bootfile.
CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
CONFIG_SYS_VXWORKS_ADD_PARAMS
Add it at the end of the bootline. E.g "u=username pw=secret"
Note: If a "bootargs" environment is defined, it will overwride
the defaults discussed just above.Serial Ports: CONFIG_PL010_SERIAL
Define this if you want support for Amba PrimeCell PL010 UARTs.
CONFIG_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
CONFIG_PL011_SERIAL_RLCR
Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
have separate receive and transmit line control registers. Set
this variable to initialize the extra register.
CONFIG_PL011_SERIAL_FLUSH_ON_INIT
On some platforms (e.g. U8500) U-Boot is loaded by a second stage
boot loader that has already initialized the UART. Define this
variable to flush the UART at init time.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)
CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
CONFIG_CONSOLE_TIME display time/date info in
upper right corner
(requires CONFIG_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
additional 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 CONFIG_SYS_BAUDRATE_TABLE, see below. CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
Console Rx buffer length With CONFIG_SYS_SMC_RXBUFLEN it is possible to define the maximum receive buffer length for the SMC. This option is actual only for 82xx and 8xx possible. If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE must be defined, to setup the maximum idle timeout for the SMC.
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_RETRYAutoboot 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 systemsSerial 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 CONFIG_CMD_KGDB is defined) CONFIG_KGDB_BAUDRATE Select one of the baudrates listed in CONFIG_SYS_BAUDRATE_TABLE, see below.
Monitor Functions: Monitor commands can be included or excluded from the build by using the #include files "config_cmd_all.h" and #undef'ing unwanted commands, or using "config_cmd_default.h" and augmenting with additional #define's for wanted commands.
The default command configuration includes all commands
except those marked below with a "*".
CONFIG_CMD_ASKENV * ask for env variable
CONFIG_CMD_BDI bdinfo
CONFIG_CMD_BEDBUG * Include BedBug Debugger
CONFIG_CMD_BMP * BMP support
CONFIG_CMD_BSP * Board specific commands
CONFIG_CMD_BOOTD bootd
CONFIG_CMD_CACHE * icache, dcache
CONFIG_CMD_CONSOLE coninfo
CONFIG_CMD_CRC32 * crc32
CONFIG_CMD_DATE * support for RTC, date/time...
CONFIG_CMD_DHCP * DHCP support
CONFIG_CMD_DIAG * Diagnostics
CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
CONFIG_CMD_DTT * Digital Therm and Thermostat
CONFIG_CMD_ECHO echo arguments
CONFIG_CMD_EDITENV edit env variable
CONFIG_CMD_EEPROM * EEPROM read/write support
CONFIG_CMD_ELF * bootelf, bootvx
CONFIG_CMD_EXPORTENV * export the environment
CONFIG_CMD_SAVEENV saveenv
CONFIG_CMD_FDC * Floppy Disk Support
CONFIG_CMD_FAT * FAT partition support
CONFIG_CMD_FDOS * Dos diskette Support
CONFIG_CMD_FLASH flinfo, erase, protect
CONFIG_CMD_FPGA FPGA device initialization support
CONFIG_CMD_GO * the 'go' command (exec code)
CONFIG_CMD_GREPENV * search environment
CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
CONFIG_CMD_I2C * I2C serial bus support
CONFIG_CMD_IDE * IDE harddisk support
CONFIG_CMD_IMI iminfo
CONFIG_CMD_IMLS List all found images
CONFIG_CMD_IMMAP * IMMR dump support
CONFIG_CMD_IMPORTENV * import an environment
CONFIG_CMD_IRQ * irqinfo
CONFIG_CMD_ITEST Integer/string test of 2 values
CONFIG_CMD_JFFS2 * JFFS2 Support
CONFIG_CMD_KGDB * kgdb
CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
CONFIG_CMD_LOADB loadb
CONFIG_CMD_LOADS loads
CONFIG_CMD_MD5SUM print md5 message digest
(requires CONFIG_CMD_MEMORY and CONFIG_MD5)
CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
loop, loopw, mtest
CONFIG_CMD_MISC Misc functions like sleep etc
CONFIG_CMD_MMC * MMC memory mapped support
CONFIG_CMD_MII * MII utility commands
CONFIG_CMD_MTDPARTS * MTD partition support
CONFIG_CMD_NAND * NAND support
CONFIG_CMD_NET bootp, tftpboot, rarpboot
CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
CONFIG_CMD_PCI * pciinfo
CONFIG_CMD_PCMCIA * PCMCIA support
CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
host
CONFIG_CMD_PORTIO * Port I/O
CONFIG_CMD_REGINFO * Register dump
CONFIG_CMD_RUN run command in env variable
CONFIG_CMD_SAVES * save S record dump
CONFIG_CMD_SCSI * SCSI Support
CONFIG_CMD_SDRAM * print SDRAM configuration information
(requires CONFIG_CMD_I2C)
CONFIG_CMD_SETGETDCR Support for DCR Register access
(4xx only)
CONFIG_CMD_SHA1SUM print sha1 memory digest
(requires CONFIG_CMD_MEMORY)
CONFIG_CMD_SOURCE "source" command Support
CONFIG_CMD_SPI * SPI serial bus support
CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
CONFIG_CMD_USB * USB support
CONFIG_CMD_CDP * Cisco Discover Protocol support
CONFIG_CMD_FSL * Microblaze FSL support
EXAMPLE: If you want all functions except of network
support you can write:
#include "config_cmd_all.h"
#undef CONFIG_CMD_NETOther Commands: fdt (flattened device tree) command: CONFIG_OF_LIBFDT
Note: Don't enable the "icache" and "dcache" commands (configuration option CONFIG_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 for the SoC. There must be support in the SoC specific code for a watchdog. For the 8xx and 8260 CPUs, the SIU Watchdog feature is enabled in the SYPCR register. When supported for a specific SoC is available, then no further board specific code should be needed to use it.
CONFIG_HW_WATCHDOG
When using a watchdog circuitry external to the used
SoC, then define this variable and provide board
specific code for the "hw_watchdog_reset" function.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 CONFIG_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_MC13783 - use MC13783 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_ISL1208 - use Intersil ISL1208 RTC
CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
CONFIG_SYS_RV3029_TCR - enable trickle charger on
RV3029 RTC.
Note that if the RTC uses I2C, then the I2C interface
must also be configured. See I2C Support, below.GPIO Support: CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO CONFIG_PCA953X_INFO - enable pca953x info command
The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
chip-ngpio pairs that tell the PCA953X driver the number of
pins supported by a particular chip.
Note that if the GPIO device 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 CONFIG_CMD_DATE .Partition Support: CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
CONFIG_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 fileATAPI 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 CONFIG_SYS_64BIT_LBA.
Whithout these , LBA48 support uses 32bit variables and will 'only'
support disks up to 2.1TB.
CONFIG_SYS_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.
CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
maximum numbers of LUNs, SCSI ID's and target
devices.
CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)NETWORK Support (PCI): CONFIG_E1000 Support for Intel 8254x gigabit chips.
CONFIG_E1000_FALLBACK_MAC
default MAC for empty EEPROM after production.
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_AT91EMAC
Support for AT91RM9200 EMAC.
CONFIG_RMII
Define this to use reduced MII inteface
CONFIG_DRIVER_AT91EMAC_QUIET
If this defined, the driver is quiet.
The driver doen't show link status messages.
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)
CONFIG_FTGMAC100
Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
CONFIG_FTGMAC100_EGIGA
Define this to use GE link update with gigabit PHY.
Define this if FTGMAC100 is connected to gigabit PHY.
If your system has 10/100 PHY only, it might not occur
wrong behavior. Because PHY usually return timeout or
useless data when polling gigabit status and gigabit
control registers. This behavior won't affect the
correctnessof 10/100 link speed update.
CONFIG_SMC911X
Support for SMSC's LAN911x and LAN921x chips
CONFIG_SMC911X_BASE
Define this to hold the physical address
of the device (I/O space)
CONFIG_SMC911X_32_BIT
Define this if data bus is 32 bits
CONFIG_SMC911X_16_BIT
Define this if data bus is 16 bits. If your processor
automatically converts one 32 bit word to two 16 bit
words you may also try CONFIG_SMC911X_32_BIT.
CONFIG_SH_ETHER
Support for Renesas on-chip Ethernet controller
CONFIG_SH_ETHER_USE_PORT
Define the number of ports to be used
CONFIG_SH_ETHER_PHY_ADDR
Define the ETH PHY's address
CONFIG_SH_ETHER_CACHE_WRITEBACK
If this option is set, the driver enables cache flush.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_PSC3_USB for USB on PSC3 CONFIG_USB_CONFIG for differential drivers: 0x00001000 for single ended drivers: 0x00005000 for differential drivers on PSC3: 0x00000100 for single ended drivers on PSC3: 0x00004100 CONFIG_SYS_USB_EVENT_POLL May be defined to allow interrupt polling instead of using asynchronous interrupts
USB Device: Define the below if you wish to use the USB console. Once firmware is rebuilt from a serial console issue the command "setenv stdin usbtty; setenv stdout usbtty" and attach your USB cable. The Unix command "dmesg" should print it has found a new device. The environment variable usbtty can be set to gserial or cdc_acm to enable your device to appear to a USB host as a Linux gserial device or a Common Device Class Abstract Control Model serial device. If you select usbtty = gserial you should be able to enumerate a Linux host by
else if using cdc_acm, simply setting the environment
variable usbtty to be cdc_acm should suffice. The following
might be defined in YourBoardName.h
CONFIG_USB_DEVICE
Define this to build a UDC device
CONFIG_USB_TTY
Define this to have a tty type of device available to
talk to the UDC device
CONFIG_SYS_CONSOLE_IS_IN_ENV
Define this if you want stdin, stdout &/or stderr to
be set to usbtty.
mpc8xx:
CONFIG_SYS_USB_EXTC_CLK 0xBLAH
Derive USB clock from external clock "blah"
- CONFIG_SYS_USB_EXTC_CLK 0x02
CONFIG_SYS_USB_BRG_CLK 0xBLAH
Derive USB clock from brgclk
- CONFIG_SYS_USB_BRG_CLK 0x04
If you have a USB-IF assigned VendorID then you may wish to
define your own vendor specific values either in BoardName.h
or directly in usbd_vendor_info.h. If you don't define
CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
should pretend to be a Linux device to it's target host.
CONFIG_USBD_MANUFACTURER
Define this string as the name of your company for
- CONFIG_USBD_MANUFACTURER "my company"
CONFIG_USBD_PRODUCT_NAME
Define this string as the name of your product
- CONFIG_USBD_PRODUCT_NAME "acme usb device"
CONFIG_USBD_VENDORID
Define this as your assigned Vendor ID from the USB
Implementors Forum. This *must* be a genuine Vendor ID
to avoid polluting the USB namespace.
- CONFIG_USBD_VENDORID 0xFFFF
CONFIG_USBD_PRODUCTID
Define this as the unique Product ID
for your device
- CONFIG_USBD_PRODUCTID 0xFFFFMMC 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 CONFIG_CMD_MMC. The MMC driver also works with the FAT fs. This is enabled with CONFIG_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
CONFIG_SYS_JFFS2_FIRST_SECTOR,
CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
Define these for a default partition on a NOR device
CONFIG_SYS_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 CONFIG_SYS_JFFS_SINGLE_PART 1
to disable the command chpart. This is the default when you
have not defined a custom partitionKeyboard 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 different 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/video/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
CONFIG_FSL_DIU_FB
Enable the Freescale DIU video driver. Reference boards for
SOCs that have a DIU should define this macro to enable DIU
support, and should also define these other macros:
CONFIG_SYS_DIU_ADDR
CONFIG_VIDEO
CONFIG_CMD_BMP
CONFIG_CFB_CONSOLE
CONFIG_VIDEO_SW_CURSOR
CONFIG_VGA_AS_SINGLE_DEVICE
CONFIG_VIDEO_LOGO
CONFIG_VIDEO_BMP_LOGO
The DIU driver will look for the 'video-mode' environment
variable, and if defined, enable the DIU as a console during
boot. See the documentation file README.video for a
description of this variable.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_ATMEL_LCD:
HITACHI TX09D70VM1CCA, 3.5", 240x320.
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
CONFIG_SYS_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.
CONFIG_SPLASH_SCREEN_ALIGN
If this option is set the splash image can be freely positioned
on the screen. Environment variable "splashpos" specifies the
position as "x,y". If a positive number is given it is used as
number of pixel from left/top. If a negative number is given it
is used as number of pixel from right/bottom. You can also
specify 'm' for centering the image.
Example:
setenv splashpos m,m
=> image at center of screen
setenv splashpos 30,20
=> image at x = 30 and y = 20
setenv splashpos -10,m
=> vertically centered image
at x = dspWidth - bmpWidth - 9Gzip 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.Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
If this option is set, 8-bit RLE compressed 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 CONFIG_SYS_MALLOC_LEN) should
be at least 4MB.
CONFIG_LZMA
If this option is set, support for lzma compressed
images is included.
Note: The LZMA algorithm adds between 2 and 4KB of code and it
requires an amount of dynamic memory that is given by the
formula:
(1846 + 768 << (lc + lp)) * sizeof(uint16)
Where lc and lp stand for, respectively, Literal context bits
and Literal pos bits.
This value is upper-bounded by 14MB in the worst case. Anyway,
for a ~4MB large kernel image, we have lc=3 and lp=0 for a
total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
a very small buffer.
Use the lzmainfo tool to determinate the lc and lp values and
then calculate the amount of needed dynamic memory (ensuring
the appropriate CONFIG_SYS_MALLOC_LEN value).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 readEthernet address: CONFIG_ETHADDR CONFIG_ETH1ADDR CONFIG_ETH2ADDR CONFIG_ETH3ADDR CONFIG_ETH4ADDR CONFIG_ETH5ADDR
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 the IP address of a TFTP
server to contact when using the "tftboot" command.
CONFIG_KEEP_SERVERADDR
Keeps the server's MAC address, in the env 'serveraddr'
for passing to bootargs (like Linux's netconsole option)Multicast TFTP Mode: CONFIG_MCAST_TFTP
Defines whether you want to support multicast TFTP as per
rfc-2090; for example to work with atftp. Lets lots of targets
tftp down the same boot image concurrently. Note: the Ethernet
driver in use must provide a function: mcast() to join/leave a
multicast group.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 inserted 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 secDHCP Advanced Options: You can fine tune the DHCP functionality by defining CONFIGBOOTP* symbols:
CONFIG_BOOTP_SUBNETMASK
CONFIG_BOOTP_GATEWAY
CONFIG_BOOTP_HOSTNAME
CONFIG_BOOTP_NISDOMAIN
CONFIG_BOOTP_BOOTPATH
CONFIG_BOOTP_BOOTFILESIZE
CONFIG_BOOTP_DNS
CONFIG_BOOTP_DNS2
CONFIG_BOOTP_SEND_HOSTNAME
CONFIG_BOOTP_NTPSERVER
CONFIG_BOOTP_TIMEOFFSET
CONFIG_BOOTP_VENDOREX
CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
environment variable, not the BOOTP server.
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 defined.
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_BOOTP_SEND_HOSTNAME is defined, the content
of the "hostname" environment variable is passed as
option 12 to the DHCP server.
CONFIG_BOOTP_DHCP_REQUEST_DELAY
A 32bit value in microseconds for a delay between
receiving a "DHCP Offer" and sending the "DHCP Request".
This fixes a problem with certain DHCP servers that don't
respond 100% of the time to a "DHCP request". E.g. On an
AT91RM9200 processor running at 180MHz, this delay needed
to be *at least* 15,000 usec before a Windows Server 2003
DHCP server would reply 100% of the time. I recommend at
least 50,000 usec to be safe. The alternative is to hope
that one of the retries will be successful but note that
the DHCP timeout and retry process takes a longer than
this delay.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 CONFIG_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 a hardware I2C controller.
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 CONFIG_SYS_I2C_SPEED
to be the frequency (in Hz) at which you wish your i2c bus
to run and CONFIG_SYS_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
(arch/powerpc/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
CONFIG_SYS_I2C_SLAVE to 0.
CONFIG_SYS_I2C_INIT_MPC5XXX
When a board is reset during an i2c bus transfer
chips might think that the current transfer is still
in progress. Reset the slave devices by sending start
commands until the slave device responds.
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)
CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
If your arch supports the generic GPIO framework (asm/gpio.h),
then you may alternatively define the two GPIOs that are to be
used as SCL / SDA. Any of the previous I2C_xxx macros will
have GPIO-based defaults assigned to them