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
-http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
-
+Please see https://lists.denx.de/pipermail/u-boot and
+https://marc.info/?l=u-boot
Where to get source code:
=========================
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
+https://source.denx.de/u-boot/u-boot.git ; you can browse it online at
+https://source.denx.de/u-boot/u-boot
-The "snapshot" links on this page allow you to download tarballs of
+The "Tags" 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/
+available from the DENX file server through HTTPS or FTP.
+https://ftp.denx.de/pub/u-boot/
+ftp://ftp.denx.de/pub/u-boot/
Where we come from:
===================
- start from 8xxrom sources
-- create PPCBoot project (http://sourceforge.net/projects/ppcboot)
+- create PPCBoot project (https://sourceforge.net/projects/ppcboot)
- clean up code
- make it easier to add custom boards
- make it possible to add other [PowerPC] CPUs
* S-Record download
* network boot
* ATA disk / SCSI ... boot
-- create ARMBoot project (http://sourceforge.net/projects/armboot)
+- create ARMBoot project (https://sourceforge.net/projects/armboot)
- add other CPU families (starting with ARM)
-- create U-Boot project (http://sourceforge.net/projects/u-boot)
-- current project page: see http://www.denx.de/wiki/U-Boot
+- create U-Boot project (https://sourceforge.net/projects/u-boot)
+- current project page: see https://www.denx.de/wiki/U-Boot
Names and Spelling:
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
/mips Files generic to MIPS architecture
/nds32 Files generic to NDS32 architecture
/nios2 Files generic to Altera NIOS2 architecture
- /openrisc Files generic to OpenRISC architecture
/powerpc Files generic to PowerPC architecture
/riscv Files generic to RISC-V architecture
/sandbox Files generic to HW-independent "sandbox"
/sh Files generic to SH architecture
/x86 Files generic to x86 architecture
-/api Machine/arch independent API for external apps
-/board Board dependent files
+ /xtensa Files generic to Xtensa architecture
+/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.
+/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:
=======================
specific to be undertaken on a native platform. The sandbox is also used to
run some of U-Boot's tests.
-See doc/arch/index.rst for more details.
+See doc/arch/sandbox.rst for more details.
Board Initialisation Flow:
- loads U-Boot or (in falcon mode) Linux
-
Configuration Options:
----------------------
CONFIG_SYS_FSL_DDR
Freescale DDR driver in use. This type of DDR controller is
- found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
- SoCs.
+ found in mpc83xx, mpc85xx as well as some ARM core SoCs.
CONFIG_SYS_FSL_DDR_ADDR
Freescale DDR memory-mapped register base.
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
* The bootm command automatically updates the fdt
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_SYSTEM_SETUP
Other code has addition modification that it wants to make
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 http://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
serverip, gatewayip, hostname, othbootargs.
It loads the vxWorks image pointed bootfile.
- Note: If a "bootargs" environment is defined, it will overwride
+ Note: If a "bootargs" environment is defined, it will override
the defaults discussed just above.
-- Cache Configuration:
- CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
-
- Cache Configuration for ARM:
CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
controller
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
Define this variable to enable hw flow control in serial driver.
Current user of this option is drivers/serial/nsl16550.c driver
-- Autoboot Command:
- CONFIG_BOOTCOMMAND
- Only needed when CONFIG_BOOTDELAY is enabled;
- define a command string that is automatically executed
- when no character is read on the console interface
- within "Boot Delay" after reset.
-
- CONFIG_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.
-
- Serial Download Echo Mode:
CONFIG_LOADS_ECHO
If defined to 1, all characters received during a
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
which adds regex support to some commands, as for
example "env grep" and "setexpr".
-- Device tree:
- CONFIG_OF_CONTROL
- If this variable is defined, U-Boot will use a device tree
- to configure its devices, instead of relying on statically
- compiled #defines in the board file. This option is
- experimental and only available on a few boards. The device
- tree is available in the global data as gd->fdt_blob.
-
- 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
- code will locate it at run-time. Generally this works by:
-
- cat u-boot.bin u-boot.dtb >image.bin
-
- and in fact, U-Boot does this for you, creating a file called
- u-boot-dtb.bin which is useful in the common case. You can
- still use the individual files if you need something more
- exotic.
-
- CONFIG_OF_BOARD
- If this variable is defined, U-Boot will use the device tree
- provided by the board at runtime instead of embedding one with
- the image. Only boards defining board_fdt_blob_setup() support
- this option (see include/fdtdec.h file).
-
- 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
- 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.
+ CONFIG_SYS_WATCHDOG_FREQ
+ Some platforms automatically call WATCHDOG_RESET()
+ from the timer interrupt handler every
+ CONFIG_SYS_WATCHDOG_FREQ interrupts. If not set by the
+ board configuration file, a default of CONFIG_SYS_HZ/2
+ (i.e. 500) is used. Setting CONFIG_SYS_WATCHDOG_FREQ
+ to 0 disables calling WATCHDOG_RESET() from the timer
+ interrupt.
- Real-Time Clock:
CONFIG_SCSI) you must configure support for at
least one non-MTD partition type as well.
-- IDE Reset method:
- CONFIG_IDE_RESET_ROUTINE - this is defined in several
- board configurations files but used nowhere!
-
- CONFIG_IDE_RESET - is this is defined, IDE Reset will
- be performed by calling the function
- ide_set_reset(int reset)
- which has to be defined in a board specific file
-
-- ATAPI Support:
- CONFIG_ATAPI
-
- Set this to enable ATAPI support.
-
- LBA48 Support
CONFIG_LBA48
When enabled, makes the IDE subsystem use 64bit sector addresses.
Default is 32bit.
-- SCSI Support:
- 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.
-
- The environment variable 'scsidevs' is set to the number of
- 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
sending again an USB request to the device.
- Journaling Flash filesystem support:
- CONFIG_JFFS2_NAND
- 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
- Keyboard Support:
See Kconfig help for available keyboard drivers.
- 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. This option is deprecated
- and is only used by novena. For new boards, use driver model
- instead.
-
- Video support:
CONFIG_FSL_DIU_FB
Enable the Freescale DIU video driver. Reference boards for
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
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)
server to contact when using the "tftboot" command.
(Environment variable "serverip")
- CONFIG_KEEP_SERVERADDR
-
- Keeps the server's MAC address, in the env 'serveraddr'
- for passing to bootargs (like Linux's netconsole option)
-
- Gateway IP address:
CONFIG_GATEWAYIP
from a BOOTP client in networks with unusually high latency.
- DHCP Advanced Options:
- You can fine tune the DHCP functionality by defining
- CONFIG_BOOTP_* symbols:
-
- CONFIG_BOOTP_NISDOMAIN
- CONFIG_BOOTP_BOOTFILESIZE
- CONFIG_BOOTP_NTPSERVER
- CONFIG_BOOTP_TIMEOFFSET
- CONFIG_BOOTP_VENDOREX
- CONFIG_BOOTP_MAY_FAIL
-
- CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
- environment variable, not the BOOTP server.
-
- CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
- after the configured retry count, the call will fail
- instead of starting over. This can be used to fail over
- to Link-local IP address configuration if the DHCP server
- is not available.
-
- 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.
- Link-local IP address negotiation:
Negotiate with other link-local clients on the local network
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.
SPI EEPROM, also an instance works with Crystal A/D and
D/As on the SACSng board)
- CONFIG_SOFT_SPI
-
- Enables a software (bit-bang) SPI driver rather than
- using hardware support. This is a general purpose
- driver that only requires three general I/O port pins
- (two outputs, one input) to function. If this is
- defined, the board configuration must define several
- SPI configuration items (port pins to use, etc). For
- an example, see include/configs/sacsng.h.
-
CONFIG_SYS_SPI_MXC_WAIT
Timeout for waiting until spi transfer completed.
default: (CONFIG_SYS_HZ/100) /* 10 ms */
Time to wait after FPGA configuration. The default is
200 ms.
-- Configuration Management:
-
- CONFIG_IDENT_STRING
-
- If defined, this string will be added to the U-Boot
- version information (U_BOOT_VERSION)
-
- Vendor Parameter Protection:
U-Boot considers the values of the environment
HERMES, IP860, RPXlite, LWMON,
FLAGADM
-- Access to physical memory region (> 4GB)
- Some basic support is provided for operations on memory not
- normally accessible to U-Boot - e.g. some architectures
- support access to more than 4GB of memory on 32-bit
- machines using physical address extension or similar.
- Define CONFIG_PHYSMEM to access this basic support, which
- currently only supports clearing the memory.
-
- Error Recovery:
CONFIG_NET_RETRY_COUNT
try longer timeout such as
#define CONFIG_NFS_TIMEOUT 10000UL
-- Command Interpreter:
- CONFIG_SYS_PROMPT_HUSH_PS2
-
- This defines the secondary prompt string, which is
- printed when the command interpreter needs more input
- to complete a command. Usually "> ".
-
Note:
In the current implementation, the local variables
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.
CONFIG_SPL_INIT_MINIMAL
Arch init code should be built for a very small image
- CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
- Partition on the MMC to load U-Boot from when the MMC is being
- used in raw mode
-
- CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
- Sector to load kernel uImage from when MMC is being
- used in raw mode (for Falcon mode)
-
CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
Sector and number of sectors to load kernel argument
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_BOARD_EARLY_INIT_F: Call board_early_init_f()
- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
- CONFIG_BOARD_LATE_INIT: Call board_late_init()
-- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
Configuration Settings:
-----------------------
Enables allocating and saving a kernel copy of the bd_info in
space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
-- CONFIG_SYS_MAX_FLASH_BANKS:
- Max number of Flash memory banks
-
- CONFIG_SYS_MAX_FLASH_SECT:
Max number of sectors on a Flash chip
If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
forced to a value that ensures that CCSR is not relocated.
-- CONFIG_IDE_AHB:
- Most IDE controllers were designed to be connected with PCI
- interface. Only few of them were designed for AHB interface.
- When software is doing ATA command and data transfer to
- IDE devices through IDE-AHB controller, some additional
- registers accessing to these kind of IDE-AHB controller
- is required.
-
- CONFIG_SYS_IMMR: Physical address of the Internal Memory.
DO NOT CHANGE unless you know exactly what you're
doing! (11-4) [MPC8xx systems only]
- CONFIG_SYS_MAMR_PTA:
periodic timer for refresh
-- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
- CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
- CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
- CONFIG_SYS_BR1_PRELIM:
- Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
-
-- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
- CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
- CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
- Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
-
-- CONFIG_PCI_ENUM_ONLY
- Only scan through and get the devices on the buses.
- Don't do any setup work, presumably because someone or
- something has already done it, and we don't need to do it
- a second time. Useful for platforms that are pre-booted
- by coreboot or similar.
-
-- 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
and in many different cross environments. Of course we cannot support
all possibly existing versions of cross development tools in all
(potentially obsolete) versions. In case of tool chain problems we
-recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
+recommend to use the ELDK (see https://www.denx.de/wiki/DULG/ELDK)
which is extensively used to build and test U-Boot.
If you are not using a native environment, it is assumed that you
sspi - SPI utility commands
base - print or set address offset
printenv- print environment variables
+pwm - control pwm channels
setenv - set environment variables
saveenv - save environment variables to persistent storage
protect - enable or disable FLASH write protection
For now: just type "help <command>".
-Environment Variables:
-======================
-
-U-Boot supports user configuration using Environment Variables which
-can be made persistent by saving to Flash memory.
-
-Environment Variables are set using "setenv", printed using
-"printenv", and saved to Flash using "saveenv". Using "setenv"
-without a value can be used to delete a variable from the
-environment. As long as you don't save the environment you are
-working with an in-memory copy. In case the Flash area containing the
-environment is erased by accident, a default environment is provided.
-
-Some configuration options can be set using Environment Variables.
-
-List of environment variables (most likely not complete):
-
- baudrate - see CONFIG_BAUDRATE
-
- bootdelay - see CONFIG_BOOTDELAY
-
- bootcmd - see CONFIG_BOOTCOMMAND
-
- bootargs - Boot arguments when booting an RTOS image
-
- bootfile - Name of the image to load with TFTP
-
- bootm_low - Memory range available for image processing in the bootm
- command can be restricted. This variable is given as
- a hexadecimal number and defines lowest address allowed
- for use by the bootm command. See also "bootm_size"
- environment variable. Address defined by "bootm_low" is
- also the base of the initial memory mapping for the Linux
- kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
- bootm_mapsize.
-
- bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
- This variable is given as a hexadecimal number and it
- defines the size of the memory region starting at base
- address bootm_low that is accessible by the Linux kernel
- during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
- as the default value if it is defined, and bootm_size is
- used otherwise.
-
- bootm_size - Memory range available for image processing in the bootm
- command can be restricted. This variable is given as
- a hexadecimal number and defines the size of the region
- allowed for use by the bootm command. See also "bootm_low"
- environment variable.
-
- bootstopkeysha256, bootdelaykey, bootstopkey - See README.autoboot
-
- updatefile - Location of the software update file on a TFTP server, used
- by the automatic software update feature. Please refer to
- documentation in doc/README.update for more details.
-
- autoload - if set to "no" (any string beginning with 'n'),
- "bootp" will just load perform a lookup of the
- configuration from the BOOTP server, but not try to
- load any image using TFTP
-
- autostart - if set to "yes", an image loaded using the "bootp",
- "rarpboot", "tftpboot" or "diskboot" commands will
- be automatically started (by internally calling
- "bootm")
-
- If set to "no", a standalone image passed to the
- "bootm" command will be copied to the load address
- (and eventually uncompressed), but NOT be started.
- This can be used to load and uncompress arbitrary
- data.
-
- fdt_high - if set this restricts the maximum address that the
- flattened device tree will be copied into upon boot.
- For example, if you have a system with 1 GB memory
- at physical address 0x10000000, while Linux kernel
- only recognizes the first 704 MB as low memory, you
- may need to set fdt_high as 0x3C000000 to have the
- device tree blob be copied to the maximum address
- of the 704 MB low memory, so that Linux kernel can
- access it during the boot procedure.
-
- If this is set to the special value 0xFFFFFFFF then
- the fdt will not be copied at all on boot. For this
- to work it must reside in writable memory, have
- sufficient padding on the end of it for u-boot to
- add the information it needs into it, and the memory
- must be accessible by the kernel.
-
- fdtcontroladdr- if set this is the address of the control flattened
- device tree used by U-Boot when CONFIG_OF_CONTROL is
- defined.
-
- i2cfast - (PPC405GP|PPC405EP only)
- if set to 'y' configures Linux I2C driver for fast
- mode (400kHZ). This environment variable is used in
- initialization code. So, for changes to be effective
- it must be saved and board must be reset.
-
- initrd_high - restrict positioning of initrd images:
- If this variable is not set, initrd images will be
- copied to the highest possible address in RAM; this
- is usually what you want since it allows for
- maximum initrd size. If for some reason you want to
- make sure that the initrd image is loaded below the
- CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
- variable to a value of "no" or "off" or "0".
- Alternatively, you can set it to a maximum upper
- address to use (U-Boot will still check that it
- does not overwrite the U-Boot stack and data).
-
- For instance, when you have a system with 16 MB
- RAM, and want to reserve 4 MB from use by Linux,
- you can do this by adding "mem=12M" to the value of
- the "bootargs" variable. However, now you must make
- sure that the initrd image is placed in the first
- 12 MB as well - this can be done with
-
- setenv initrd_high 00c00000
-
- If you set initrd_high to 0xFFFFFFFF, this is an
- indication to U-Boot that all addresses are legal
- for the Linux kernel, including addresses in flash
- memory. In this case U-Boot will NOT COPY the
- ramdisk at all. This may be useful to reduce the
- boot time on your system, but requires that this
- feature is supported by your Linux kernel.
-
- ipaddr - IP address; needed for tftpboot command
-
- loadaddr - Default load address for commands like "bootp",
- "rarpboot", "tftpboot", "loadb" or "diskboot"
-
- loads_echo - see CONFIG_LOADS_ECHO
-
- serverip - TFTP server IP address; needed for tftpboot command
-
- bootretry - see CONFIG_BOOT_RETRY_TIME
-
- bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
-
- bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
-
- ethprime - controls which interface is used first.
-
- ethact - controls which interface is currently active.
- For example you can do the following
-
- => setenv ethact FEC
- => ping 192.168.0.1 # traffic sent on FEC
- => setenv ethact SCC
- => ping 10.0.0.1 # traffic sent on SCC
-
- ethrotate - When set to "no" U-Boot does not go through all
- available network interfaces.
- It just stays at the currently selected interface.
-
- netretry - When set to "no" each network operation will
- either succeed or fail without retrying.
- When set to "once" the network operation will
- fail when all the available network interfaces
- are tried once without success.
- Useful on scripts which control the retry operation
- themselves.
-
- npe_ucode - set load address for the NPE microcode
-
- silent_linux - If set then Linux will be told to boot silently, by
- changing the console to be empty. If "yes" it will be
- made silent. If "no" it will not be made silent. If
- unset, then it will be made silent if the U-Boot console
- is silent.
-
- tftpsrcp - If this is set, the value is used for TFTP's
- UDP source port.
-
- 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,
- we use the TFTP server's default block size
-
- tftptimeout - Retransmission timeout for TFTP packets (in milli-
- seconds, minimum value is 1000 = 1 second). Defines
- when a packet is considered to be lost so it has to
- be retransmitted. The default is 5000 = 5 seconds.
- Lowering this value may make downloads succeed
- 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.
-
- tftpwindowsize - if this is set, the value is used for TFTP's
- window size as described by RFC 7440.
- This means the count of blocks we can receive before
- sending ack to server.
-
- 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.
-
- memmatches - Number of matches found by the last 'ms' command, in hex
-
- memaddr - Address of the last match found by the 'ms' command, in hex,
- or 0 if none
-
- mempos - Index position of the last match found by the 'ms' command,
- in units of the size (.b, .w, .l) of the search
-
- zbootbase - (x86 only) Base address of the bzImage 'setup' block
-
- zbootaddr - (x86 only) Address of the loaded bzImage, typically
- BZIMAGE_LOAD_ADDR which is 0x100000
-
-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
-variable names. "File Name" gives the name of the file on a TFTP
-server, "RAM Address" gives the location in RAM the image will be
-loaded to, and "Flash Location" gives the image's address in NOR
-flash or offset in NAND flash.
-
-*Note* - these variables don't have to be defined for all boards, some
-boards currently use other variables for these purposes, and some
-boards use these variables for other purposes.
-
-Image File Name RAM Address Flash Location
------ --------- ----------- --------------
-u-boot u-boot u-boot_addr_r u-boot_addr
-Linux kernel bootfile kernel_addr_r kernel_addr
-device tree blob fdtfile fdt_addr_r fdt_addr
-ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
-
-The following environment variables may be used and automatically
-updated by the network boot commands ("bootp" and "rarpboot"),
-depending the information provided by your boot server:
-
- bootfile - see above
- dnsip - IP address of your Domain Name Server
- dnsip2 - IP address of your secondary Domain Name Server
- gatewayip - IP address of the Gateway (Router) to use
- hostname - Target hostname
- ipaddr - see above
- netmask - Subnet Mask
- rootpath - Pathname of the root filesystem on the NFS server
- serverip - see above
-
-
-There are two special Environment Variables:
-
- serial# - contains hardware identification information such
- as type string and/or serial number
- ethaddr - Ethernet address
-
-These variables can be set only once (usually during manufacturing of
-the board). U-Boot refuses to delete or overwrite these variables
-once they have been set once.
-
-
-Further special Environment Variables:
-
- ver - Contains the U-Boot version string as printed
- with the "version" command. This variable is
- readonly (see CONFIG_VERSION_VARIABLE).
-
-
-Please note that changes to some configuration parameters may take
-only effect after the next boot (yes, that's just like Windoze :-).
-
-
-Callback functions for environment variables:
----------------------------------------------
-
-For some environment variables, the behavior of u-boot needs to change
-when their values are changed. This functionality allows functions to
-be associated with arbitrary variables. On creation, overwrite, or
-deletion, the callback will provide the opportunity for some side
-effect to happen or for the change to be rejected.
-
-The callbacks are named and associated with a function using the
-U_BOOT_ENV_CALLBACK macro in your board or driver code.
-
-These callbacks are associated with variables in one of two ways. The
-static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
-in the board configuration to a string that defines a list of
-associations. The list must be in the following format:
-
- entry = variable_name[:callback_name]
- list = entry[,list]
-
-If the callback name is not specified, then the callback is deleted.
-Spaces are also allowed anywhere in the list.
-
-Callbacks can also be associated by defining the ".callbacks" variable
-with the same list format above. Any association in ".callbacks" will
-override any association in the static list. You can define
-CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
-".callbacks" environment variable in the default or embedded environment.
-
-If CONFIG_REGEX is defined, the variable_name above is evaluated as a
-regular expression. This allows multiple variables to be connected to
-the same callback without explicitly listing them all out.
-
-The signature of the callback functions is:
-
- int callback(const char *name, const char *value, enum env_op op, int flags)
-
-* name - changed environment variable
-* value - new value of the environment variable
-* op - operation (create, overwrite, or delete)
-* flags - attributes of the environment variable change, see flags H_* in
- include/search.h
-
-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:
=======================================
* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
- Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
- INTEGRITY).
+ Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, INTEGRITY).
* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC).
Load Address: 0x00000000
Entry Point: 0x00000000
-The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
-option performs the converse operation of the mkimage's second form (the "-d"
-option). Given an image built by mkimage, the dumpimage extracts a "data file"
-from the image:
-
- tools/dumpimage -i image -T type -p position data_file
- -i ==> extract from the 'image' a specific 'data_file'
- -T ==> set image type to 'type'
- -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
-
+The "dumpimage" tool can be used to disassemble or list the contents of images
+built by mkimage. See dumpimage's help output (-h) for details.
Installing a Linux Image:
-------------------------
Unix, I recommend to use C-Kermit for general purpose use (and
especially for kermit binary protocol download ("loadb" command), and
use "cu" for S-Record download ("loads" command). See
-http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
+https://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
for help with kermit.
Note: on ARM, only R_ARM_RELATIVE relocations are supported.
On Nios II, the ABI is documented here:
- http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
+ https://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
==> U-Boot will use gp to hold a pointer to the global data
while (learning) {
Read the README file in the top level directory;
- Read http://www.denx.de/twiki/bin/view/DULG/Manual;
+ Read https://www.denx.de/wiki/bin/view/DULG/Manual;
Read applicable doc/README.*;
Read the source, Luke;
/* find . -name "*.[chS]" | xargs grep -i <keyword> */
establish some rules. Submissions which do not conform to these rules
may be rejected, even when they contain important and valuable stuff.
-Please see http://www.denx.de/wiki/U-Boot/Patches for details.
+Please see https://www.denx.de/wiki/U-Boot/Patches for details.
Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
see https://lists.denx.de/listinfo/u-boot
projects / platform / kernel / u-boot.git / blobdiff