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 starts with start.S with three functions called during init after
-that. The purpose and limitations of each is described below.
+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
+
+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
CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
Number of controllers used for other than main memory.
+ CONFIG_SYS_FSL_HAS_DP_DDR
+ Defines the SoC has DP-DDR used for DPAA.
+
CONFIG_SYS_FSL_SEC_BE
Defines the SEC controller register space as Big Endian
(0-5, cf. cfb_console.c)
VIDEO_FB_ADRS framebuffer address
VIDEO_KBD_INIT_FCT keyboard int fct
- (i.e. i8042_kbd_init())
+ (i.e. rx51_kp_init())
VIDEO_TSTC_FCT test char fct
- (i.e. i8042_tstc)
+ (i.e. rx51_kp_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)
+ (i.e. rx51_kp_getc)
CONFIG_VIDEO_LOGO display Linux logo in
upper left corner
CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
'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.
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_TPM
Support TPM devices.
- CONFIG_TPM_TIS_I2C
- Support for i2c bus TPM devices. Only one device
+ CONFIG_TPM_TIS_INFINEON
+ Support for Infineon i2c bus TPM devices. Only one device
per system is supported at this time.
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.
a default value of 65536 will be defined.
- Keyboard Support:
- CONFIG_ISA_KEYBOARD
-
- Define this to enable standard (PC-Style) keyboard
- support
+ See Kconfig help for available keyboard drivers.
- 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.
+ CONFIG_KEYBOARD
- CONFIG_CROS_EC_KEYB
- Enables a Chrome OS keyboard using the CROS_EC interface.
- This uses CROS_EC to communicate with a second microcontroller
- which provides key scans on request.
+ Define this to enable a custom keyboard support.
+ This simply calls drv_keyboard_init() which must be
+ defined in your board-specific files. This option is deprecated
+ and is only used by novena. For new boards, use driver model
+ instead.
- Video support:
CONFIG_VIDEO
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
- CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
- CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
- CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
+ - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
+ - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
+ - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
+ - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
+ - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
+ - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
+ - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
+ - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
+ - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
additional defines:
Enables the driver for SPI controller on SuperH. Currently
only SH7757 is supported.
- 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
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
CONFIG_SYS_SPL_MALLOC_START
Starting address of the malloc pool used in SPL.
+ When this option is set the full malloc is used in SPL and
+ it is set up by spl_init() and before that, the simple malloc()
+ can be used if CONFIG_SYS_MALLOC_F is defined.
CONFIG_SYS_SPL_MALLOC_SIZE
The size of the malloc pool used in 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:
------------------------------
Scratch address used by the alternate memory test
You only need to set this if address zero isn't writeable
-- CONFIG_SYS_MEM_TOP_HIDE (PPC only):
+- CONFIG_SYS_MEM_RESERVE_SECURE
+ 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
+ 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:
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
- 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.
unset, then it will be made silent if the U-Boot console
is silent.
- tftpsrcport - If this is set, the value is used for TFTP's
+ tftpsrcp - If this is set, the value is used for TFTP's
UDP source port.
- tftpdstport - If this is set, the value is used for TFTP's UDP
+ tftpdstp - If this is set, the value is used for TFTP's UDP
destination port instead of the Well Know Port 69.
tftpblocksize - Block size to use for TFTP transfers; if not set,
faster in networks with high packet loss rates or
with unreliable TFTP servers.
+ tftptimeoutcountmax - maximum count of TFTP timeouts (no
+ unit, minimum value = 0). Defines how many timeouts
+ can happen during a single file transfer before that
+ transfer is aborted. The default is 10, and 0 means
+ 'no timeouts allowed'. Increasing this value may help
+ downloads succeed with high packet loss rates, or with
+ unreliable TFTP servers or client hardware.
+
vlan - When set to a value < 4095 the traffic over
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.