version as needed.
- preloader_console_init() can be called here in extremis
- should set up SDRAM, and anything needed to make the UART work
- - these is no need to clear BSS, it will be done by crt0.S
+ - there is no need to clear BSS, it will be done by crt0.S
- for specific scenarios on certain architectures an early BSS *can*
be made available (via CONFIG_SPL_EARLY_BSS by moving the clearing
of BSS prior to entering board_init_f()) but doing so is discouraged.
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.
- Optional CONFIG_TULIP_SELECT_MEDIA for board specific
- modem chip initialisation (KS8761/QS6611).
-
CONFIG_NATSEMI
Support for National dp83815 chips.
Enables an 'i2c edid' command which can read EDID
information over I2C from an attached LCD display.
-- Splash Screen Support: CONFIG_SPLASH_SCREEN
-
- If this option is set, the environment is checked for
- a variable "splashimage". If found, the usual display
- of logo, copyright and system information on the LCD
- is suppressed and the BMP image at the address
- specified in "splashimage" is loaded instead. The
- console is redirected to the "nulldev", too. This
- allows for a "silent" boot where a splash screen is
- loaded very quickly after power-on.
-
- CONFIG_SPLASHIMAGE_GUARD
-
- If this option is set, then U-Boot will prevent the environment
- variable "splashimage" from being set to a problematic address
- (see doc/README.displaying-bmps).
- This option is useful for targets where, due to alignment
- restrictions, an improperly aligned BMP image will cause a data
- abort. If you think you will not have problems with unaligned
- accesses (for example because your toolchain prevents them)
- there is no need to set this option.
-
- CONFIG_SPLASH_SCREEN_ALIGN
-
- If this option is set the splash image can be freely positioned
- on the screen. Environment variable "splashpos" specifies the
- position as "x,y". If a positive number is given it is used as
- number of pixel from left/top. If a negative number is given it
- is used as number of pixel from right/bottom. You can also
- specify 'm' for centering the image.
-
- Example:
- setenv splashpos m,m
- => image at center of screen
-
- setenv splashpos 30,20
- => image at x = 30 and y = 20
-
- setenv splashpos -10,m
- => vertically centered image
- at x = dspWidth - bmpWidth - 9
-
- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
If this option is set, additionally to standard BMP
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
- activate this driver with CONFIG_SYS_I2C_RCAR
- This driver adds 4 i2c buses
- - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
- - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
- - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
- - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
- - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
- - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
- - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
- - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
- - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
-
- drivers/i2c/sh_i2c.c:
- activate this driver with CONFIG_SYS_I2C_SH
- This driver adds from 2 to 5 i2c buses
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_MEMTEST_SCRATCH:
- Scratch address used by the alternate memory test
- You only need to set this if address zero isn't writeable
-
- 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:
$ CROSS_COMPILE=ppc_4xx-
$ export CROSS_COMPILE
-Note: If you wish to generate Windows versions of the utilities in
- the tools directory you can use the MinGW toolchain
- (http://www.mingw.org). Set your HOST tools to the MinGW
- toolchain and execute 'make tools'. For example:
-
- $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
-
- Binaries such as tools/mkimage.exe will be created which can
- be executed on computers running Windows.
-
U-Boot is intended to be simple to build. After installing the
sources you must configure U-Boot for one specific board type. This
is done by typing:
make NAME_defconfig
where "NAME_defconfig" is the name of one of the existing configu-
-rations; see boards.cfg for supported names.
+rations; see configs/*_defconfig for supported names.
-Note: for some board special configuration names may exist; check if
+Note: for some boards special configuration names may exist; check if
additional information is available from the board vendor; for
instance, the TQM823L systems are available without (standard)
or with LCD support. You can select such additional "features"
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
while (learning) {
Read the README file in the top level directory;
Read http://www.denx.de/twiki/bin/view/DULG/Manual;
- Read applicable doc/*.README;
+ Read applicable doc/README.*;
Read the source, Luke;
/* find . -name "*.[chS]" | xargs grep -i <keyword> */
}
* For new features: a description of the feature and your
implementation.
-* A CHANGELOG entry as plaintext (separate from the patch)
-
* For major contributions, add a MAINTAINERS file with your
information and associated file and directory references.
projects / platform / kernel / u-boot.git / blobdiff