/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
kernel configuration options. The intention is to make it easier to
build a config tool - later.
+- ARM Platform Bus Type(CCI):
+ CoreLink Cache Coherent Interconnect (CCI) is ARM BUS which
+ provides full cache coherency between two clusters of multi-core
+ CPUs and I/O coherency for devices and I/O masters
+
+ CONFIG_SYS_FSL_HAS_CCI400
+
+ Defined For SoC that has cache coherent interconnect
+ CCN-400
+
+ CONFIG_SYS_FSL_HAS_CCN504
+
+ Defined for SoC that has cache coherent interconnect CCN-504
The following options need to be configured:
supported, core will start to execute uboot when wakes up.
- Generic CPU options:
- CONFIG_SYS_GENERIC_GLOBAL_DATA
- Defines global data is initialized in generic board board_init_f().
- If this macro is defined, global data is created and cleared in
- generic board board_init_f(). Without this macro, architecture/board
- should initialize global data before calling board_init_f().
-
CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
Defines the endianess of the CPU. Implementation of those
when no character is read on the console interface
within "Boot Delay" after reset.
- CONFIG_BOOTARGS
- This can be used to pass arguments to the bootm
- command. The value of CONFIG_BOOTARGS goes into the
- environment value "bootargs".
-
CONFIG_RAMBOOT and CONFIG_NFSBOOT
The value of these goes into the environment as
"ramboot" and "nfsboot" respectively, and can be used
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->blob.
+ the global data structure as gd->fdt_blob.
CONFIG_OF_SEPARATE
If this variable is defined, U-Boot will build a device tree
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
entering dfuMANIFEST state. Host waits this timeout, before
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_ANDROID_BOOT_IMAGE
- This enables support for booting images which use the Android
- image format header.
-
- 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_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.
-
- CONFIG_FASTBOOT_FLASH
- The fastboot protocol includes a "flash" command for writing
- the downloaded image to a non-volatile storage device. Define
- this to enable the "fastboot flash" command.
-
- CONFIG_FASTBOOT_FLASH_MMC_DEV
- The fastboot "flash" command requires additional information
- regarding the non-volatile storage device. Define this to
- the eMMC device that fastboot should use to store the image.
-
- CONFIG_FASTBOOT_GPT_NAME
- The fastboot "flash" command supports writing the downloaded
- image to the Protective MBR and the Primary GUID Partition
- Table. (Additionally, this downloaded image is post-processed
- to generate and write the Backup GUID Partition Table.)
- This occurs when the specified "partition name" on the
- "fastboot flash" command line matches this value.
- The default is "gpt" if undefined.
-
- CONFIG_FASTBOOT_MBR_NAME
- The fastboot "flash" command supports writing the downloaded
- image to DOS MBR.
- This occurs when the "partition name" specified on the
- "fastboot flash" command line matches this value.
- If not defined the default value "mbr" is used.
-
- Journaling Flash filesystem support:
CONFIG_JFFS2_NAND
Define these for a default partition on a NAND device
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
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_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
Define this if you need to first read the OOB and then the
data. This is used, for example, on davinci platforms.
- CONFIG_SPL_OMAP3_ID_NAND
- Support for an OMAP3-specific set of functions to return the
- ID and MFR of the first attached NAND chip, if present.
-
CONFIG_SPL_RAM_DEVICE
Support for running image already present in ram, in SPL binary
Please note that the environment is read-only until the monitor
has been relocated to RAM and a RAM copy of the environment has been
-created; also, when using EEPROM you will have to use getenv_f()
+created; also, when using EEPROM you will have to use env_get_f()
until then to read environment variables.
The environment is protected by a CRC32 checksum. Before the monitor
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: 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: