/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
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
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_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:
------------------
projects / people / ms / u-boot.git / blobdiff