/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
RAM and NFS.
- Bootcount:
- CONFIG_BOOTCOUNT_LIMIT
- Implements a mechanism for detecting a repeating reboot
- cycle, see:
- http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
-
CONFIG_BOOTCOUNT_ENV
If no softreset save registers are found on the hardware
"bootcount" is stored in the environment. To prevent a
control registers. This behavior won't affect the
correctnessof 10/100 link speed update.
- CONFIG_SMC911X
- Support for SMSC's LAN911x and LAN921x chips
-
- CONFIG_SMC911X_BASE
- Define this to hold the physical address
- of the device (I/O space)
-
- CONFIG_SMC911X_32_BIT
- Define this if data bus is 32 bits
-
- CONFIG_SMC911X_16_BIT
- Define this if data bus is 16 bits. If your processor
- automatically converts one 32 bit word to two 16 bit
- words you may also try CONFIG_SMC911X_32_BIT.
-
CONFIG_SH_ETHER
Support for Renesas on-chip Ethernet controller
See doc/README.link-local for more information.
+ - MAC address from environment variables
+
+ FDT_SEQ_MACADDR_FROM_ENV
+
+ Fix-up device tree with MAC addresses fetched sequentially from
+ environment variables. This config work on assumption that
+ non-usable ethernet node of device-tree are either not present
+ or their status has been marked as "disabled".
+
- CDP Options:
CONFIG_CDP_DEVICE_ID
SPI EEPROM, also an instance works with Crystal A/D and
D/As on the SACSng board)
- CONFIG_SH_SPI
-
- Enables the driver for SPI controller on SuperH. Currently
- only SH7757 is supported.
-
CONFIG_SOFT_SPI
Enables a software (bit-bang) SPI driver rather than
Currently supported on some MPC8xxx processors. For an
example, see include/configs/mpc8349emds.h.
- CONFIG_MXC_SPI
-
- Enables the driver for the SPI controllers on i.MX and MXC
- SoCs. Currently i.MX31/35/51 are supported.
-
CONFIG_SYS_SPI_MXC_WAIT
Timeout for waiting until spi transfer completed.
default: (CONFIG_SYS_HZ/100) /* 10 ms */
currently only supports clearing the memory.
- Error Recovery:
- CONFIG_PANIC_HANG
-
- Define this variable to stop the system in case of a
- fatal error, so that you have to reset it manually.
- This is probably NOT a good idea for an embedded
- system where you want the system to reboot
- automatically as fast as possible, but it may be
- useful during development since you can try to debug
- the conditions that lead to the situation.
-
CONFIG_NET_RETRY_COUNT
This variable defines the number of retries for
this is instead controlled by the value of
/config/load-environment.
-- DataFlash Support:
- CONFIG_HAS_DATAFLASH
-
- Defining this option enables DataFlash features and
- allows to read/write in Dataflash via the standard
- commands cp, md...
-
- Serial Flash support
Usage requires an initial 'sf probe' to define the serial
flash parameters, followed by read/write/erase/update
CONFIG_SF_DEFAULT_MODE (see include/spi.h)
CONFIG_SF_DEFAULT_SPEED in Hz
- CONFIG_SYSTEMACE
-
- Adding this option adds support for Xilinx SystemACE
- chips attached via some sort of local bus. The address
- of the chip must also be defined in the
- CONFIG_SYS_SYSTEMACE_BASE macro. For example:
-
- #define CONFIG_SYSTEMACE
- #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
-
- When SystemACE support is added, the "ace" device type
- becomes available to the fat commands, i.e. fatls.
- TFTP Fixed UDP Port:
CONFIG_TFTP_PORT
but sometimes that is not allowed.
- bootcount support:
- CONFIG_BOOTCOUNT_LIMIT
-
- This enables the bootcounter support, see:
- http://www.denx.de/wiki/DULG/UBootBootCountLimit
-
CONFIG_AT91SAM9XE
enable special bootcounter support on at91sam9xe based boards.
CONFIG_SOC_DA8XX
CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
the bootcounter.
CONFIG_BOOTCOUNT_ALEN = address len
+ CONFIG_BOOTCOUNT_EXT
+ enable support for the bootcounter in EXT filesystem
+ CONFIG_SYS_BOOTCOUNT_ADDR = RAM address used for read
+ and write.
+ CONFIG_SYS_BOOTCOUNT_EXT_INTERFACE = interface
+ CONFIG_SYS_BOOTCOUNT_EXT_DEVPART = device and part
+ CONFIG_SYS_BOOTCOUNT_EXT_NAME = filename
- Show boot progress:
CONFIG_SHOW_BOOT_PROGRESS
CONFIG_SYS_SPL_MALLOC_SIZE
The size of the malloc pool used in SPL.
- CONFIG_SPL_FRAMEWORK
- Enable the SPL framework under common/. This framework
- supports MMC, NAND and YMODEM loading of U-Boot and NAND
- NAND loading of the Linux Kernel.
-
CONFIG_SPL_OS_BOOT
Enable booting directly to an OS from SPL.
See also: doc/README.falcon
globally (CONFIG_CMD_MEMORY).
- CONFIG_SKIP_LOWLEVEL_INIT
- [ARM, NDS32, MIPS only] If this variable is defined, then certain
+ [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.
Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
variable.
+User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by
+setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS.
+For example to treat all compiler warnings as errors:
+
+ make KCFLAGS=-Werror
Please be aware that the Makefiles assume you are using GNU make, so
for instance on NetBSD you might need to use "gmake" instead of
NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
or current versions of GCC may "optimize" the code too much.
+On RISC-V, the following registers are used:
+
+ x0: hard-wired zero (zero)
+ x1: return address (ra)
+ x2: stack pointer (sp)
+ x3: global pointer (gp)
+ x4: thread pointer (tp)
+ x5: link register (t0)
+ x8: frame pointer (fp)
+ x10-x11: arguments/return values (a0-1)
+ x12-x17: arguments (a2-7)
+ x28-31: temporaries (t3-6)
+ pc: program counter (pc)
+
+ ==> U-Boot will use gp to hold a pointer to the global data
+
Memory Management:
------------------
-----------------
All contributions to U-Boot should conform to the Linux kernel
-coding style; see the file "Documentation/CodingStyle" and the script
-"scripts/Lindent" in your Linux kernel source directory.
+coding style; see the kernel coding style guide at
+https://www.kernel.org/doc/html/latest/process/coding-style.html, and the
+script "scripts/Lindent" in your Linux kernel source directory.
Source files originating from a different project (for example the
MTD subsystem) are generally exempt from these guidelines and are not
Please see http://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 http://lists.denx.de/mailman/listinfo/u-boot
+see https://lists.denx.de/listinfo/u-boot
When you send a patch, please include the following information with
it:
projects / people / ms / u-boot.git / blobdiff