/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
/configs Board default configuration files
- loads U-Boot or (in falcon mode) Linux
-
Configuration Options:
----------------------
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_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)
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