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 boards.cfg file lists board
-maintainers.
+In case of problems see the CHANGELOG file to find out who contributed
+the specific port. In addition, there are various MAINTAINERS files
+scattered throughout the U-Boot source identifying the people or
+companies responsible for various boards and subsystems.
-Note: There is no CHANGELOG file in the actual U-Boot source tree;
-it can be created dynamically from the Git log using:
+Note: As of August, 2010, there is no longer a CHANGELOG file in the
+actual U-Boot source tree; however, it can be created dynamically
+from the Git log using:
make CHANGELOG
==================
In case you have questions about, problems with or contributions for
-U-Boot you should send a message to the U-Boot mailing list at
+U-Boot, you should send a message to the U-Boot mailing list at
<u-boot@lists.denx.de>. 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
Where to get source code:
=========================
-The U-Boot source code is maintained in the git repository at
+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
/arch Architecture specific files
/arc Files generic to ARC architecture
- /cpu CPU specific files
- /arc700 Files specific to ARC 700 CPUs
- /lib Architecture specific library 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
- /at91 Files specific to Atmel AT91RM9200 CPU
- /imx Files specific to Freescale MC9328 i.MX CPUs
- /s3c24x0 Files specific to Samsung S3C24X0 CPUs
- /arm926ejs Files specific to ARM 926 CPUs
- /arm1136 Files specific to ARM 1136 CPUs
- /pxa Files specific to Intel XScale PXA 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
/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
- /mips32 Files specific to MIPS32 CPUs
- /mips64 Files specific to MIPS64 CPUs
- /lib Architecture specific library files
/nds32 Files generic to NDS32 architecture
- /cpu CPU specific files
- /n1213 Files specific to Andes Technology N1213 CPUs
- /lib Architecture specific library files
/nios2 Files generic to Altera NIOS2 architecture
- /cpu CPU specific files
- /lib Architecture specific library files
/openrisc Files generic to OpenRISC architecture
- /cpu CPU specific files
- /lib Architecture specific library files
/powerpc Files generic to PowerPC architecture
- /cpu CPU specific files
- /mpc5xx Files specific to Freescale MPC5xx CPUs
- /mpc5xxx Files specific to Freescale MPC5xxx CPUs
- /mpc8xx Files specific to Freescale MPC8xx 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
+ /sandbox Files generic to HW-independent "sandbox"
/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
/x86 Files generic to x86 architecture
- /cpu CPU specific files
- /lib Architecture specific library files
/api Machine/arch independent API for external apps
/board Board dependent files
/common Misc architecture independent functions
+/configs Board default configuration files
/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
+/lib Library routines generic to all architectures
+/Licenses Various license files
/net Networking code
/post Power On Self Test
-/spl Secondary Program Loader framework
+/scripts Various build scripts and Makefiles
+/test Various unit test files
/tools Tools to build S-Record or U-Boot images, etc.
Software Configuration:
you don't know what you're doing; they have names beginning with
"CONFIG_SYS_".
-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.
+Previously, all configuration was done by hand, which involved creating
+symbolic links and editing configuration files manually. More recently,
+U-Boot has added the Kbuild infrastructure used by the Linux kernel,
+allowing you to use the "make menuconfig" command to configure your
+build.
Selection of Processor Architecture and Board Type:
cd u-boot
make TQM823L_defconfig
-For the Cogent platform, you need to specify the CPU type as well;
-e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
-directory according to the instructions in cogent/README.
-
+Note: If you're looking for the default configuration file for a board
+you're sure used to be there but is now missing, check the file
+doc/README.scrapyard for a list of no longer supported boards.
Sandbox Environment:
--------------------
--------------------------
This is the intended start-up flow for boards. This should apply for both
-SPL and U-Boot proper (i.e. they both follow the same rules). At present SPL
-mostly uses a separate code path, but the funtion names and roles of each
-function are the same. Some boards or architectures may not conform to this.
-At least most ARM boards which use CONFIG_SPL_FRAMEWORK conform to this.
+SPL and U-Boot proper (i.e. they both follow the same rules).
+
+Note: "SPL" stands for "Secondary Program Loader," which is explained in
+more detail later in this file.
+
+At present, SPL mostly uses a separate code path, but the function names
+and roles of each function are the same. Some boards or architectures
+may not conform to this. At least most ARM boards which use
+CONFIG_SPL_FRAMEWORK conform to this.
+
+Execution typically starts with an architecture-specific (and possibly
+CPU-specific) start.S file, such as:
+
+ - arch/arm/cpu/armv7/start.S
+ - arch/powerpc/cpu/mpc83xx/start.S
+ - arch/mips/cpu/start.S
-Execution starts with start.S with three functions called during init after
-that. The purpose and limitations of each is described below.
+and so on. From there, three functions are called; the purpose and
+limitations of each of these functions are described below.
lowlevel_init():
- purpose: essential init to permit execution to reach board_init_f()
CONFIG_SYS_CPC_REINIT_F
This CONFIG is defined when the CPC is configured as SRAM at the
- time of U-boot entry and is required to be re-initialized.
+ time of U-Boot entry and is required to be re-initialized.
CONFIG_DEEP_SLEEP
Indicates this SoC supports deep sleep feature. If deep sleep is
implemetation.
CONFIG_SYS_FSL_DDR2
- Board config to use DDR2. It can be eanbeld for SoCs with
+ Board config to use DDR2. It can be enabled for SoCs with
Freescale DDR2 or DDR3 controllers, depending on the board
implementation.
CONFIG_CONSOLE_EXTRA_INFO
additional board info beside
the logo
+ CONFIG_HIDE_LOGO_VERSION
+ do not display bootloader
+ version string
When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
a limited number of ANSI escape sequences (cursor control,
'Sane' compilers will generate smaller code if
CONFIG_PRE_CON_BUF_SZ is a power of 2
-- Safe printf() functions
- Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
- the printf() functions. These are defined in
- include/vsprintf.h and include snprintf(), vsnprintf() and
- so on. Code size increase is approximately 300-500 bytes.
- If this option is not given then these functions will
- silently discard their buffer size argument - this means
- you are not getting any overflow checking in this case.
-
-- Boot Delay: CONFIG_BOOTDELAY - in seconds
- Delay before automatically booting the default image;
- set to -1 to disable autoboot.
- set to -2 to autoboot with no delay and not check for abort
- (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
-
- 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_ZERO_BOOTDELAY_CHECK
- CONFIG_RESET_TO_RETRY
-
- Autoboot Command:
CONFIG_BOOTCOMMAND
Only needed when CONFIG_BOOTDELAY is enabled;
CONFIG_CMD_ECHO echo arguments
CONFIG_CMD_EDITENV edit env variable
CONFIG_CMD_EEPROM * EEPROM read/write support
+ CONFIG_CMD_EEPROM_LAYOUT* EEPROM layout aware commands
CONFIG_CMD_ELF * bootelf, bootvx
CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
CONFIG_CMD_ENV_FLAGS * display details about env flags
CONFIG_CMD_GO * the 'go' command (exec code)
CONFIG_CMD_GREPENV * search environment
CONFIG_CMD_HASH * calculate hash / digest
- 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_RUN run command in env variable
CONFIG_CMD_SANDBOX * sb command to access sandbox features
CONFIG_CMD_SAVES * save S record dump
- CONFIG_CMD_SCSI * SCSI Support
+ CONFIG_SCSI * SCSI Support
CONFIG_CMD_SDRAM * print SDRAM configuration information
(requires CONFIG_CMD_I2C)
CONFIG_CMD_SETGETDCR Support for DCR Register access
XXX - this list needs to get updated!
+- Removal of commands
+ If no commands are needed to boot, you can disable
+ CONFIG_CMDLINE to remove them. In this case, the command line
+ will not be available, and when U-Boot wants to execute the
+ boot command (on start-up) it will call board_run_command()
+ instead. This can reduce image size significantly for very
+ simple boot procedures.
+
- Regular expression support:
CONFIG_REGEX
If this variable is defined, U-Boot is linked against
CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
- CONFIG_CMD_SCSI) you must configure support for at
+ CONFIG_SCSI) you must configure support for at
least one non-MTD partition type as well.
- IDE Reset method:
CONFIG_TPM_TIS_I2C_BURST_LIMITATION
Define the burst count bytes upper limit
+ CONFIG_TPM_ST33ZP24
+ Support for STMicroelectronics TPM devices. Requires DM_TPM support.
+
+ CONFIG_TPM_ST33ZP24_I2C
+ Support for STMicroelectronics ST33ZP24 I2C devices.
+ Requires TPM_ST33ZP24 and I2C.
+
+ CONFIG_TPM_ST33ZP24_SPI
+ Support for STMicroelectronics ST33ZP24 SPI devices.
+ Requires TPM_ST33ZP24 and SPI.
+
CONFIG_TPM_ATMEL_TWI
Support for Atmel TWI TPM device. Requires I2C support.
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
+ boot. See the documentation file doc/README.video for a
description of this variable.
- LCD Support: CONFIG_LCD
If this option is set, then U-Boot will prevent the environment
variable "splashimage" from being set to a problematic address
- (see README.displaying-bmps).
+ (see doc/README.displaying-bmps).
This option is useful for targets where, due to alignment
restrictions, an improperly aligned BMP image will cause a data
abort. If you think you will not have problems with unaligned
with a special header) as build targets. By defining
CONFIG_BUILD_TARGET in the SoC / board header, this
special image will be automatically built upon calling
- make / MAKEALL.
+ make / buildman.
CONFIG_IDENT_STRING
Enable editing and History functions for interactive
command line input operations
+- Command Line PS1/PS2 support:
+ CONFIG_CMDLINE_PS_SUPPORT
+
+ Enable support for changing the command prompt string
+ at run-time. Only static string is supported so far.
+ The string is obtained from environment variables PS1
+ and PS2.
+
- Default Environment:
CONFIG_EXTRA_ENV_SETTINGS
- Parallel Flash support:
CONFIG_SYS_NO_FLASH
- Traditionally U-boot was run on systems with parallel NOR
+ Traditionally U-Boot was run on systems with parallel NOR
flash. This option is used to disable support for parallel NOR
flash. This option should be defined if the board does not have
parallel flash.
will set it back to normal. This command currently
supports i.MX53 and i.MX6.
-- Signing support:
- CONFIG_RSA
-
- This enables the RSA algorithm used for FIT image verification
- in U-Boot. See doc/uImage.FIT/signature.txt for more information.
-
- The Modular Exponentiation algorithm in RSA is implemented using
- driver model. So CONFIG_DM needs to be enabled by default for this
- library to function.
-
- The signing part is build into mkimage regardless of this
- option. The software based modular exponentiation is built into
- mkimage irrespective of this option.
-
- bootcount support:
CONFIG_BOOTCOUNT_LIMIT
enabled per default for backward compatibility.
- FIT image support:
- CONFIG_FIT
- Enable support for the FIT uImage format.
-
- CONFIG_FIT_BEST_MATCH
- When no configuration is explicitly selected, default to the
- one whose fdt's compatibility field best matches that of
- U-Boot itself. A match is considered "best" if it matches the
- most specific compatibility entry of U-Boot's fdt's root node.
- The order of entries in the configuration's fdt is ignored.
-
- CONFIG_FIT_SIGNATURE
- This option enables signature verification of FIT uImages,
- using a hash signed and verified using RSA. If
- CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
- hashing is available using hardware, RSA library will use it.
- See doc/uImage.FIT/signature.txt for more details.
-
- WARNING: When relying on signed FIT images with required
- signature check the legacy image format is default
- disabled. If a board need legacy image format support
- enable this through CONFIG_IMAGE_FORMAT_LEGACY
-
CONFIG_FIT_DISABLE_SHA256
Supporting SHA256 hashes has quite an impact on binary size.
For constrained systems sha256 hash support can be disabled
with this option.
+ TODO(sjg@chromium.org): Adjust this option to be positive,
+ and move it to Kconfig
+
- Standalone program support:
CONFIG_STANDALONE_LOAD_ADDR
consider that a completely unreadable NAND block is bad,
and thus should be skipped silently.
+ CONFIG_SPL_ABORT_ON_RAW_IMAGE
+ When defined, SPL will proceed to another boot method
+ if the image it has loaded does not have a signature.
+
CONFIG_SPL_RELOC_STACK
Adress of the start of the stack SPL will use after
relocation. If unspecified, this is equal to
Support for NAND boot using simple NAND drivers that
expose the cmd_ctrl() interface.
+ CONFIG_SPL_UBI
+ Support for a lightweight UBI (fastmap) scanner and
+ loader
+
CONFIG_SPL_MTD_SUPPORT
Support for the MTD subsystem within SPL. Useful for
environment on NAND support within SPL.
CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
-Modem Support:
---------------
-
-[so far only for SMDK2400 boards]
-
-- Modem support enable:
- CONFIG_MODEM_SUPPORT
-
-- RTS/CTS Flow control enable:
- CONFIG_HWFLOW
-
-- Modem debug support:
- CONFIG_MODEM_SUPPORT_DEBUG
-
- Enables debugging stuff (char screen[1024], dbg())
- for modem support. Useful only with BDI2000.
-
- Interrupt support (PPC):
There are common interrupt_init() and timer_interrupt()
/ other_activity_monitor it works automatically from
general timer_interrupt().
-- General:
-
- In the target system modem support is enabled when a
- specific key (key combination) is pressed during
- power-on. Otherwise U-Boot will boot normally
- (autoboot). The key_pressed() function is called from
- board_init(). Currently key_pressed() is a dummy
- function, returning 1 and thus enabling modem
- initialization.
-
- If there are no modem init strings in the
- environment, U-Boot proceed to autoboot; the
- previous output (banner, info printfs) will be
- suppressed, though.
-
- See also: doc/README.Modem
Board initialization settings:
------------------------------
You only need to set this if address zero isn't writeable
- CONFIG_SYS_MEM_RESERVE_SECURE
+ Only implemented for ARMv8 for now.
If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
is substracted from total RAM and won't be reported to OS.
This memory can be used as secure memory. A variable
- gd->secure_ram is used to track the location. In systems
+ gd->arch.secure_ram is used to track the location. In systems
the RAM base is not zero, or RAM is divided into banks,
this variable needs to be recalcuated to get the address.
-- CONFIG_SYS_MEM_TOP_HIDE (PPC only):
+- CONFIG_SYS_MEM_TOP_HIDE:
If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
this specified memory area will get subtracted from the top
(end) of RAM and won't get "touched" at all by U-Boot. By
The memory will be freed (or in fact just forgotten) when
U-Boot relocates itself.
- Pre-relocation malloc() is only supported on ARM and sandbox
- at present but is fairly easy to enable for other archs.
-
- CONFIG_SYS_MALLOC_SIMPLE
Provides a simple and small malloc() and calloc() for those
boards which do not use the full malloc in SPL (which is
If defined, don't allow the -f switch to env set override variable
access flags.
-- CONFIG_SYS_GENERIC_BOARD
- This selects the architecture-generic board system instead of the
- architecture-specific board files. It is intended to move boards
- to this new framework over time. Defining this will disable the
- arch/foo/lib/board.c file and use common/board_f.c and
- common/board_r.c instead. To use this option your architecture
- must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
- If you find problems enabling this option on your board please report
- the problem and send patches!
-
- CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
This is set by OMAP boards for the max time that reset should
be asserted. See doc/README.omap-reset-time for details on how
other boot loader or by a debugger which performs
these initializations itself.
+- CONFIG_SKIP_LOWLEVEL_INIT_ONLY
+ [ARM926EJ-S only] This allows just the call to lowlevel_init()
+ to be skipped. The normal CP15 init (such as enabling the
+ instruction cache) is still performed.
+
- CONFIG_SPL_BUILD
Modifies the behaviour of start.S when compiling a loader
that is executed before the actual U-Boot. E.g. when
- CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE
Define minimum DDR size required for debug server image
-- CONFIG_SYS_MEM_TOP_HIDE_MIN
- Define minimum DDR size to be hided from top of the DDR memory
+- CONFIG_SYS_MC_RSV_MEM_ALIGN
+ Define alignment of reserved memory MC requires
Reproducible builds
-------------------
to port U-Boot to your hardware platform. To do this, follow these
steps:
-1. Add a new configuration option for your board to the toplevel
- "boards.cfg" file, using the existing entries as examples.
- Follow the instructions there to keep the boards in order.
-2. Create a new directory to hold your board specific code. Add any
+1. Create a new directory to hold your board specific code. Add any
files you need. In your board directory, you will need at least
- the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
-3. Create a new configuration file "include/configs/<board>.h" for
- your board
+ the "Makefile" and a "<board>.c".
+2. Create a new configuration file "include/configs/<board>.h" for
+ your board.
3. If you're porting U-Boot to a new CPU, then also create a new
directory to hold your CPU specific code. Add any files you need.
4. Run "make <board>_defconfig" with your new name.
But before you submit such a patch, please verify that your modifi-
cation did not break existing code. At least make sure that *ALL* of
the supported boards compile WITHOUT ANY compiler warnings. To do so,
-just run the "MAKEALL" script, which will configure and build U-Boot
-for ALL supported system. Be warned, this will take a while. You can
-select which (cross) compiler to use by passing a `CROSS_COMPILE'
-environment variable to the script, i. e. to use the ELDK cross tools
-you can type
-
- CROSS_COMPILE=ppc_8xx- MAKEALL
-
-or to build on a native PowerPC system you can type
-
- CROSS_COMPILE=' ' MAKEALL
-
-When using the MAKEALL script, the default behaviour is to build
-U-Boot in the source directory. This location can be changed by
-setting the BUILD_DIR environment variable. Also, for each target
-built, the MAKEALL script saves two log files (<target>.ERR and
-<target>.MAKEALL) in the <source dir>/LOG directory. This default
-location can be changed by setting the MAKEALL_LOGDIR environment
-variable. For example:
-
- export BUILD_DIR=/tmp/build
- export MAKEALL_LOGDIR=/tmp/log
- CROSS_COMPILE=ppc_8xx- MAKEALL
-
-With the above settings build objects are saved in the /tmp/build,
-log files are saved in the /tmp/log and the source tree remains clean
-during the whole build process.
+just run the buildman script (tools/buildman/buildman), which will
+configure and build U-Boot for ALL supported system. Be warned, this
+will take a while. Please see the buildman README, or run 'buildman -H'
+for documentation.
See also "U-Boot Porting Guide" below.
Ethernet is encapsulated/received over 802.1q
VLAN tagged frames.
+ bootpretryperiod - Period during which BOOTP/DHCP sends retries.
+ Unsigned value, in milliseconds. If not set, the period will
+ be either the default (28000), or a value based on
+ CONFIG_NET_RETRY_COUNT, if defined. This value has
+ precedence over the valu based on CONFIG_NET_RETRY_COUNT.
+
The following image location variables contain the location of images
used in booting. The "Image" column gives the role of the image and is
not an environment variable name. The other columns are environment
* A CHANGELOG entry as plaintext (separate from the patch)
-* For major contributions, your entry to the CREDITS file
+* For major contributions, add a MAINTAINERS file with your
+ information and associated file and directory references.
* When you add support for a new board, don't forget to add a
maintainer e-mail address to the boards.cfg file, too.
Notes:
-* Before sending the patch, run the MAKEALL script on your patched
+* Before sending the patch, run the buildman script on your patched
source tree and make sure that no errors or warnings are reported
for any of the boards.
projects / people / ms / u-boot.git / blobdiff