Directory Hierarchy:
====================
-/arch Architecture specific files
+/arch Architecture-specific files
/arc Files generic to ARC architecture
/arm Files generic to ARM architecture
/m68k Files generic to m68k architecture
/sh Files generic to SH architecture
/x86 Files generic to x86 architecture
/xtensa Files generic to Xtensa architecture
-/api Machine/arch independent API for external apps
-/board Board dependent files
+/api Machine/arch-independent API for external apps
+/board Board-dependent files
+/boot Support for images and booting
/cmd U-Boot commands functions
-/common Misc architecture independent functions
+/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
-/dts Contains Makefile for building internal U-Boot fdt.
-/env Environment files
+/doc Documentation (a mix of ReST and READMEs)
+/drivers Device drivers
+/dts Makefile for building internal U-Boot fdt.
+/env Environment support
/examples Example code for standalone applications, etc.
/fs Filesystem code (cramfs, ext2, jffs2, etc.)
/include Header Files
/post Power On Self Test
/scripts Various build scripts and Makefiles
/test Various unit test files
-/tools Tools to build S-Record or U-Boot images, etc.
+/tools Tools to build and sign FIT images, etc.
Software Configuration:
=======================
- loads U-Boot or (in falcon mode) Linux
-
Configuration Options:
----------------------
Board config to use DDR3L. It can be enabled for SoCs with
DDR3L controllers.
- CONFIG_SYS_FSL_DDR4
- Board config to use DDR4. It can be enabled for SoCs with
- DDR4 controllers.
-
CONFIG_SYS_FSL_IFC_BE
Defines the IFC controller register space as Big Endian
CONFIG_SYS_FSL_LBC_CLK_DIV
Defines divider of platform clock(clock input to eLBC controller).
- CONFIG_SYS_FSL_PBL_PBI
- It enables addition of RCW (Power on reset configuration) in built image.
- Please refer doc/README.pblimage for more details
-
- CONFIG_SYS_FSL_PBL_RCW
- It adds PBI(pre-boot instructions) commands in u-boot build image.
- PBI commands can be used to configure SoC before it starts the execution.
- Please refer doc/README.pblimage for more details
-
CONFIG_SYS_FSL_DDR_BE
Defines the DDR controller register space as Big Endian
crash. This is needed for buggy hardware (uc101) where
no pull down resistor is connected to the signal IDE5V_DD7.
- CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
-
- This setting is mandatory for all boards that have only one
- machine type and must be used to specify the machine type
- number as it appears in the ARM machine registry
- (see https://www.arm.linux.org.uk/developer/machines/).
- Only boards that have multiple machine types supported
- in a single configuration file and the machine type is
- runtime discoverable, do not have to use this setting.
-
- vxWorks boot parameters:
bootvx constructs a valid bootline using the following
controller register space
- 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
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.
-
- Removal of commands
If no commands are needed to boot, you can disable
CONFIG_CMDLINE to remove them. In this case, the command line
U-Boot needs to get its device tree from somewhere. This can
be done using one of the three options below:
- CONFIG_OF_EMBED
- If this variable is defined, U-Boot will embed a device tree
- binary in its image. This device tree file should be in the
- board directory and called <soc>-<board>.dts. The binary file
- is then picked up in board_init_f() and made available through
- the global data structure as gd->fdt_blob.
-
CONFIG_OF_SEPARATE
If this variable is defined, U-Boot will build a device tree
binary. It will be called u-boot.dtb. Architecture-specific
SCSI devices found during the last scan.
- NETWORK Support (PCI):
- CONFIG_E1000
- Support for Intel 8254x/8257x gigabit chips.
-
CONFIG_E1000_SPI
Utility code for direct access to the SPI bus on Intel 8257x.
This does not do anything useful unless you set at least one
of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
- CONFIG_E1000_SPI_GENERIC
- Allow generic access to the SPI bus on the Intel 8257x, for
- example with the "sspi" command.
-
CONFIG_NATSEMI
Support for National dp83815 chips.
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_CALXEDA_XGMAC
Support for the Calxeda XGMAC device
whether the enumeration has succeded at high speed or full
speed.
- CONFIG_SYS_CONSOLE_IS_IN_ENV
- Define this if you want stdin, stdout &/or stderr to
- be set to usbtty.
-
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
Support drawing of RLE8-compressed bitmaps on the LCD.
- CONFIG_I2C_EDID
-
- Enables an 'i2c edid' command which can read EDID
- information over I2C from an attached LCD display.
-
- MII/PHY support:
CONFIG_PHY_CLOCK_FREQ (ppc4xx)
In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
with a list of GPIO LEDs that have inverted polarity.
-- I2C Support: CONFIG_SYS_I2C
-
- This enable the NEW i2c subsystem, and will allow you to use
- i2c commands at the u-boot command line (as long as you set
- CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
- for defining speed and slave address
- - activate second bus with I2C_SOFT_DECLARATIONS2 define
- CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
- for defining speed and slave address
- - activate third bus with I2C_SOFT_DECLARATIONS3 define
- CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
- for defining speed and slave address
- - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
- CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
- for defining speed and slave address
-
- - drivers/i2c/fsl_i2c.c:
- - activate i2c driver with CONFIG_SYS_I2C_FSL
- define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
- offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
- CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
- bus.
- - If your board supports a second fsl i2c bus, define
- CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
- CONFIG_SYS_FSL_I2C2_SPEED for the speed and
- CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
- second bus.
-
- - drivers/i2c/tegra_i2c.c:
- - activate this driver with CONFIG_SYS_I2C_TEGRA
- - This driver adds 4 i2c buses with a fix speed from
- 100000 and the slave addr 0!
-
- - drivers/i2c/ppc4xx_i2c.c
- - activate this driver with CONFIG_SYS_I2C_PPC4XX
- - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
- - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
-
- - drivers/i2c/i2c_mxc.c
- - activate this driver with CONFIG_SYS_I2C_MXC
- - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
- - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
- - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
- - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
- - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
- - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
- - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
- - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
- - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
- - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
- - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
- - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
- If those defines are not set, default value is 100000
- for speed, and 0 for slave.
-
- - drivers/i2c/rcar_i2c.c:
- - activate this driver with CONFIG_SYS_I2C_RCAR
- - This driver adds 4 i2c buses
-
- - drivers/i2c/sh_i2c.c:
- - activate this driver with CONFIG_SYS_I2C_SH
- - This driver adds from 2 to 5 i2c buses
-
- - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
- - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
- - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
- - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
- - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
- - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
- - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
- - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
- - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
- - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
- - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
-
- - drivers/i2c/omap24xx_i2c.c
- - activate this driver with CONFIG_SYS_I2C_OMAP24XX
- - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
- - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
- - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
- - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
- - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
- - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
- - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
- - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
- - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
- - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
-
- - drivers/i2c/s3c24x0_i2c.c:
- - activate this driver with CONFIG_SYS_I2C_S3C24X0
- - This driver adds i2c buses (11 for Exynos5250, Exynos5420
- 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
- with a fix speed from 100000 and the slave addr 0!
-
- - drivers/i2c/ihs_i2c.c
- - activate this driver with CONFIG_SYS_I2C_IHS
- - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
- - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
- - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
- - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
- - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
- - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
- - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
- - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
- - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
- - 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:
-
+- I2C Support:
CONFIG_SYS_NUM_I2C_BUSES
Hold the number of i2c buses you want to use.
CONFIG_SPL
Enable building of SPL globally.
- CONFIG_SPL_LDSCRIPT
- LDSCRIPT for linking the SPL binary.
-
CONFIG_SPL_MAX_FOOTPRINT
Maximum size in memory allocated to the SPL, BSS included.
When defined, the linker checks that the actual memory
CONFIG_SYS_SPL_MALLOC_SIZE
The size of the malloc pool used in SPL.
- CONFIG_SPL_OS_BOOT
- Enable booting directly to an OS from SPL.
- See also: doc/README.falcon
-
CONFIG_SPL_DISPLAY_PRINT
For ARM, enable an optional function to print more information
about the running system.
Defines the size and behavior of the NAND that SPL uses
to read U-Boot
- CONFIG_SYS_NAND_U_BOOT_OFFS
- Location in NAND to read U-Boot from
-
CONFIG_SYS_NAND_U_BOOT_DST
Location in memory to load U-Boot to
CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
-- CONFIG_PCI_INDIRECT_BRIDGE:
- Enable support for indirect PCI bridges.
-
- CONFIG_SYS_SRIO:
Chip has SRIO or not
This only takes effect if the memory commands are activated
globally (CONFIG_CMD_MEMORY).
-- CONFIG_SKIP_LOWLEVEL_INIT
- [ARM, NDS32, MIPS, RISC-V only] If this variable is defined, then certain
- low level initializations (like setting up the memory
- controller) are omitted and/or U-Boot does not
- relocate itself into RAM.
-
- Normally this variable MUST NOT be defined. The only
- exception is when U-Boot is loaded (to RAM) by some
- 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
Set when the currently-running compilation is for an artifact
that will end up in the SPL (as opposed to the TPL or U-Boot
The return value is 0 if the variable change is accepted and 1 otherwise.
-Command Line Parsing:
-=====================
-
-There are two different command line parsers available with U-Boot:
-the old "simple" one, and the much more powerful "hush" shell:
-
-Old, simple command line parser:
---------------------------------
-
-- supports environment variables (through setenv / saveenv commands)
-- several commands on one line, separated by ';'
-- variable substitution using "... ${name} ..." syntax
-- special characters ('$', ';') can be escaped by prefixing with '\',
- for example:
- setenv bootcmd bootm \${address}
-- You can also escape text by enclosing in single apostrophes, for example:
- setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
-
-Hush shell:
------------
-
-- similar to Bourne shell, with control structures like
- if...then...else...fi, for...do...done; while...do...done,
- until...do...done, ...
-- supports environment ("global") variables (through setenv / saveenv
- commands) and local shell variables (through standard shell syntax
- "name=value"); only environment variables can be used with "run"
- command
-
-General rules:
---------------
-
-(1) If a command line (or an environment variable executed by a "run"
- command) contains several commands separated by semicolon, and
- one of these commands fails, then the remaining commands will be
- executed anyway.
-
-(2) If you execute several variables with one call to run (i. e.
- calling run with a list of variables as arguments), any failing
- command will cause "run" to terminate, i. e. the remaining
- variables are not executed.
Note for Redundant Ethernet Interfaces:
=======================================
projects / platform / kernel / u-boot.git / blobdiff