exists, unlike the similar options in the Linux kernel. Do not
set these options unless they apply!
+ COUNTER_FREQUENCY
+ Generic timer clock source frequency.
+
+ COUNTER_FREQUENCY_REAL
+ Generic timer clock source frequency if the real clock is
+ different from COUNTER_FREQUENCY, and can only be determined
+ at run time.
+
NOTE: The following can be machine specific errata. These
do have ability to provide rudimentary version and machine
specific checks, but expect no product checks.
bytes are output before the console is initialised, the
earlier bytes are discarded.
+ Note that when printing the buffer a copy is made on the
+ stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
+
'Sane' compilers will generate smaller code if
CONFIG_PRE_CON_BUF_SZ is a power of 2
CONFIG_AUTOBOOT_PROMPT
CONFIG_AUTOBOOT_DELAY_STR
CONFIG_AUTOBOOT_STOP_STR
- CONFIG_AUTOBOOT_DELAY_STR2
- CONFIG_AUTOBOOT_STOP_STR2
CONFIG_ZERO_BOOTDELAY_CHECK
CONFIG_RESET_TO_RETRY
Monitor commands can be included or excluded
from the build by using the #include files
<config_cmd_all.h> and #undef'ing unwanted
- commands, or using <config_cmd_default.h>
- and augmenting with additional #define's
- for wanted commands.
+ commands, or adding #define's for wanted commands.
The default command configuration includes all commands
except those marked below with a "*".
key for the Replay Protection Memory Block partition in eMMC.
- USB Device Firmware Update (DFU) class support:
- CONFIG_DFU_FUNCTION
+ CONFIG_USB_FUNCTION_DFU
This enables the USB portion of the DFU USB class
CONFIG_CMD_DFU
sending again an USB request to the device.
- USB Device Android Fastboot support:
+ CONFIG_USB_FUNCTION_FASTBOOT
+ This enables the USB part of the fastboot gadget
+
CONFIG_CMD_FASTBOOT
This enables the command "fastboot" which enables the Android
fastboot mode for the platform's USB device. Fastboot is a USB
This enables support for booting images which use the Android
image format header.
- CONFIG_USB_FASTBOOT_BUF_ADDR
+ CONFIG_FASTBOOT_BUF_ADDR
The fastboot protocol requires a large memory buffer for
downloads. Define this to the starting RAM address to use for
downloaded images.
- CONFIG_USB_FASTBOOT_BUF_SIZE
+ CONFIG_FASTBOOT_BUF_SIZE
The fastboot protocol requires a large memory buffer for
downloads. This buffer should be as large as possible for a
platform. Define this to the size available RAM for fastboot.
boot. See the documentation file README.video for a
description of this variable.
- CONFIG_VIDEO_VGA
-
- Enable the VGA video / BIOS for x86. The alternative if you
- are using coreboot is to use the coreboot frame buffer
- driver.
-
- Keyboard Support:
CONFIG_KEYBOARD
Some PHY like Intel LXT971A need extra delay after
command issued before MII status register can be read
-- Ethernet address:
- CONFIG_ETHADDR
- CONFIG_ETH1ADDR
- CONFIG_ETH2ADDR
- CONFIG_ETH3ADDR
- CONFIG_ETH4ADDR
- CONFIG_ETH5ADDR
-
- Define a default value for Ethernet address to use
- for the respective Ethernet interface, in case this
- is not determined automatically.
-
- IP address:
CONFIG_IPADDR
- define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
If those defines are not set, default value is 100000
for speed, and 0 for slave.
+ - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
+ - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
- drivers/i2c/rcar_i2c.c:
- activate this driver with CONFIG_SYS_I2C_RCAR
completely disabled. Anybody can change or delete
these parameters.
- Alternatively, if you #define _both_ CONFIG_ETHADDR
- _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
+ Alternatively, if you define _both_ an ethaddr in the
+ default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
Ethernet address is installed in the environment,
which can be changed exactly ONCE by the user. [The
serial# is unaffected by this, i. e. it remains
this is instead controlled by the value of
/config/load-environment.
+- Parallel Flash support:
+ CONFIG_SYS_NO_FLASH
+
+ 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.
+
+ If this option is not defined one of the generic flash drivers
+ (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
+ selected or the board must provide an implementation of the
+ flash API (see include/flash.h).
+
- DataFlash Support:
CONFIG_HAS_DATAFLASH
Define this option to include a destructive SPI flash
test ('sf test').
- CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
-
- Define this option to use the Bank addr/Extended addr
- support on SPI flashes which has size > 16Mbytes.
-
CONFIG_SF_DUAL_FLASH Dual flash memories
Define this option to use dual flash support where two flash
list, simply add an entry for the same variable name to the
".flags" variable.
+ If CONFIG_REGEX is defined, the variable_name above is evaluated as a
+ regular expression. This allows multiple variables to define the same
+ flags without explicitly listing them for each variable.
+
- CONFIG_ENV_ACCESS_IGNORE_FORCE
If defined, don't allow the -f switch to env set override variable
access flags.
- CONFIG_FSL_DDR_SYNC_REFRESH
Enable sync of refresh for multiple controllers.
+- CONFIG_FSL_DDR_BIST
+ Enable built-in memory test for Freescale DDR controllers.
+
- CONFIG_SYS_83XX_DDR_USES_CS0
Only for 83xx systems. If specified, then DDR should
be configured using CS0 and CS1 instead of CS2 and CS3.
normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
virtual address in NOR flash.
+Freescale Layerscape Debug Server Support:
+-------------------------------------------
+The Freescale Layerscape Debug Server Support supports the loading of
+"Debug Server firmware" and triggering SP boot-rom.
+This firmware often needs to be loaded during U-Boot booting.
+
+- CONFIG_FSL_DEBUG_SERVER
+ Enable the Debug Server for Layerscape SoCs.
+
+- 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
+
+Reproducible builds
+-------------------
+
+In order to achieve reproducible builds, timestamps used in the U-Boot build
+process have to be set to a fixed value.
+
+This is done using the SOURCE_DATE_EPOCH environment variable.
+SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
+option for U-Boot or an environment variable in U-Boot.
+
+SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
+
Building the Software:
======================
flash or offset in NAND flash.
*Note* - these variables don't have to be defined for all boards, some
-boards currenlty use other variables for these purposes, and 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
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.
+
Command Line Parsing:
=====================
warning is printed.
o If neither SROM nor the environment contain a MAC address, an error
- is raised.
+ is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
+ a random, locally-assigned MAC is used.
If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
will be programmed into hardware as part of the initialization process. This