such as ARM architectural timer initialization.
- Linux Kernel Interface:
- CONFIG_CLOCKS_IN_MHZ
-
- U-Boot stores all clock information in Hz
- internally. For binary compatibility with older Linux
- kernels (which expect the clocks passed in the
- bd_info data to be in MHz) the environment variable
- "clocks_in_mhz" can be defined so that U-Boot
- converts clock data to MHZ before passing it to the
- Linux kernel.
- When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
- "clocks_in_mhz=1" is automatically included in the
- default environment.
-
CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
When transferring memsize parameter to Linux, some versions
Define this variable to enable hw flow control in serial driver.
Current user of this option is drivers/serial/nsl16550.c driver
-- Console Baudrate:
- CONFIG_BAUDRATE - in bps
- Select one of the baudrates listed in
- CONFIG_SYS_BAUDRATE_TABLE, see below.
-
- Autoboot Command:
CONFIG_BOOTCOMMAND
Only needed when CONFIG_BOOTDELAY is enabled;
Allow generic access to the SPI bus on the Intel 8257x, for
example with the "sspi" command.
- CONFIG_EEPRO100
- Support for Intel 82557/82559/82559ER chips.
- Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
- write routine for first time initialisation.
-
- CONFIG_TULIP
- Support for Digital 2114x chips.
-
CONFIG_NATSEMI
Support for National dp83815 chips.
can be displayed via the splashscreen support or the
bmp command.
-- Compression support:
- CONFIG_GZIP
-
- Enabled by default to support gzip compressed images.
-
- CONFIG_BZIP2
-
- If this option is set, support for bzip2 compressed
- images is included. If not, only uncompressed and gzip
- compressed images are supported.
-
- NOTE: the bzip2 algorithm requires a lot of RAM, so
- the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
- be at least 4MB.
-
- MII/PHY support:
CONFIG_PHY_CLOCK_FREQ (ppc4xx)
CONFIG_BOOTP_NISDOMAIN
CONFIG_BOOTP_BOOTFILESIZE
- CONFIG_BOOTP_SEND_HOSTNAME
CONFIG_BOOTP_NTPSERVER
CONFIG_BOOTP_TIMEOFFSET
CONFIG_BOOTP_VENDOREX
to Link-local IP address configuration if the DHCP server
is not available.
- CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
- to do a dynamic update of a DNS server. To do this, they
- need the hostname of the DHCP requester.
- If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
- of the "hostname" environment variable is passed as
- option 12 to the DHCP server.
-
CONFIG_BOOTP_DHCP_REQUEST_DELAY
A 32bit value in microseconds for a delay between
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_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
- based realtime clock chips or other i2c devices. See
- common/cmd_i2c.c for a description of the command line
- interface.
-
- ported i2c driver to the new framework:
- - drivers/i2c/soft_i2c.c:
- - activate first bus with CONFIG_SYS_I2C_SOFT define
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
parameters from when MMC is being used in raw mode
(for falcon mode)
- CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
- Partition on the MMC to load U-Boot from when the MMC is being
- used in fs mode
-
CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
Filename to read to load U-Boot when reading from filesystem
CONFIG_SPL_SKIP_RELOCATE
Avoid SPL relocation
- CONFIG_SPL_NAND_BASE
- Include nand_base.c in the SPL. Requires
- CONFIG_SPL_NAND_DRIVERS.
-
- CONFIG_SPL_NAND_DRIVERS
- SPL uses normal NAND drivers, not minimal drivers.
-
CONFIG_SPL_NAND_IDENT
SPL uses the chip ID list to identify the NAND flash.
Requires CONFIG_SPL_NAND_BASE.
- CONFIG_SPL_NAND_ECC
- Include standard software ECC in the SPL
-
- CONFIG_SPL_NAND_SIMPLE
- Support for NAND boot using simple NAND drivers that
- expose the cmd_ctrl() interface.
-
CONFIG_SPL_UBI
Support for a lightweight UBI (fastmap) scanner and
loader
- CONFIG_SYS_BAUDRATE_TABLE:
List of legal baudrate settings for this board.
-- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
- Begin and End addresses of the area used by the
- simple memory test.
-
- CONFIG_SYS_MEM_RESERVE_SECURE
Only implemented for ARMv8 for now.
If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
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.
-
The following definitions that deal with the placement and management
of environment data (variable area); in general, we support the
following configurations:
mm - memory modify (auto-incrementing)
nm - memory modify (constant address)
mw - memory write (fill)
+ms - memory search
cp - memory copy
cmp - memory compare
crc32 - checksum calculation
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.
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
+
+
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