一 uboot 命令介绍
Tiny 4412 开机倒数3秒计时的时候，按下 enter 键将进入 uboot 终端。
输入 ? 或者 help 可以查看 uboot 支持的所有命令
TINY4412 # ?
? - alias for 'help'
base - print or set address offset
bdinfo - print Board Info structure
boot - boot default, i.e., run 'bootcmd'
bootd - boot default, i.e., run 'bootcmd'
bootelf - Boot from an ELF image in memory
bootm - boot application image from memory
bootp - boot image via network using BOOTP/TFTP protocol
bootvx - Boot vxWorks from an ELF image
chpart - change active partition
cmp - memory compare
coninfo - print console devices and information
cp - memory copy
crc32 - checksum calculation
dcache - enable or disable data cache
dnw - dnw - initialize USB device and ready to receive for Windows server (specific)
echo - echo args to console
editenv - edit environment variable
emmc - Open/Close eMMC boot Partition
env - environment handling commands
exit - exit script
ext2format- ext2format - disk format by ext2
ext2load- load binary file from a Ext2 filesystem
ext2ls - list files in a directory (default /)
ext3format- ext3format - disk format by ext3
false - do nothing, unsuccessfully
fastboot- fastboot- use USB Fastboot protocol
fatformat- fatformat - disk format by FAT32
fatinfo - fatinfo - print information about filesystem
fatload - fatload - load binary file from a dos filesystem
fatls - list files in a directory (default /)
fdisk - fdisk for sd/mmc.
go - start application at address 'addr'
help - print command description/usage
icache - enable or disable instruction cache
iminfo - print header information for application image
imxtract- extract a part of a multi-image
itest - return true/false on integer compare
loadb - load binary file over serial line (kermit mode)
loads - load S-Record file over serial line
loady - load binary file over serial line (ymodem mode)
loop - infinite loop on address range
md - memory display
mm - memory modify (auto-incrementing address)
mmc - MMC sub system
mmcinfo - mmcinfo <dev num>-- display MMC info
movi - movi - sd/mmc r/w sub system for SMDK board
mtdparts- define flash/nand partitions
mtest - simple RAM read/write test
mw - memory write (fill)
nfs - boot image via network using NFS protocol
nm - memory modify (constant address)
ping - send ICMP ECHO_REQUEST to network host
printenv- print environment variables
reginfo - print register information
reset - Perform RESET of the CPU
run - run commands in an environment variable
saveenv - save environment variables to persistent storage
setenv - set environment variables
showvar - print local hushshell variables
sleep - delay execution for some time
source - run script from memory
test - minimal test like /bin/sh
tftpboot- boot image via network using TFTP protocol
true - do nothing, successfully
usb - USB sub-system
version - print monitor version
uboot 支持很多命令，命令对应的源文件都在 common 目录下
user@vmware:~/tiny4412/FriendlyARM.uboot-2010.12/common$ ls
bedbug.c cmd_exit.o cmd_mii.c cmd_source.c dlmalloc.c kgdb.c
cmd_ambapp.c cmd_ext2.c cmd_misc.c cmd_source.o dlmalloc.o kgdb_stubs.c
cmd_bdinfo.c cmd_ext2.o cmd_misc.o cmd_spibootldr.c dlmalloc.src lcd.c
cmd_bdinfo.o cmd_fastboot.c cmd_mmc.c cmd_spi.c env_auto.c libcommon.o
cmd_bedbug.c cmd_fastboot.o cmd_mmc_fdisk.c cmd_strings.c env_auto.o lynxkdi.c
cmd_bmp.c cmd_fat.c cmd_mmc_fdisk.o cmd_terminal.c env_common.c main.c
cmd_boot.c cmd_fat.o cmd_mmc.o cmd_test.c env_common.o main.o
cmd_bootldr.c cmd_fdc.c cmd_movi.c cmd_test.o env_dataflash.c Makefile
cmd_bootm.c cmd_fdos.c cmd_movi.o cmd_tsi148.c env_eeprom.c memsize.c
cmd_bootm.o cmd_fdt.c cmd_mp.c cmd_ubi.c env_embedded.c memsize.o
cmd_boot.o cmd_flash.c cmd_mtdparts.c cmd_ubifs.c env_flash.c miiphyutil.c
cmd_cache.c cmd_fpga.c cmd_mtdparts.o cmd_universe.c env_mgdisk.c modem.c
cmd_cache.o cmd_help.c cmd_nand.c cmd_usb.c env_mmc.c serial.c
cmd_console.c cmd_help.o cmd_net.c cmd_usbd3.c env_nand.c serial.o
cmd_console.o cmd_i2c.c cmd_net.o cmd_usbd.c env_nowhere.c s_record.c
cmd_cplbinfo.c cmd_ide.c cmd_nvedit.c cmd_usbd.o env_nvram.c s_record.o
cmd_cramfs.c cmd_immap.c cmd_nvedit.o cmd_usb.o env_onenand.c stdio.c
cmd_dataflash_mmc_mux.c cmd_irq.c cmd_onenand.c cmd_version.c env_sf.c stdio.o
cmd_date.c cmd_itest.c cmd_otp.c cmd_version.o exports.c system_map.c
cmd_dcr.c cmd_itest.o cmd_pci.c cmd_vfd.c exports.o update.c
cmd_df.c cmd_jffs2.c cmd_pcmcia.c cmd_ximg.c fdt_support.c usb.c
cmd_diag.c cmd_license.c cmd_pcmcia.o cmd_ximg.o flash.c usb_kbd.c
cmd_display.c cmd_load.c cmd_portio.c cmd_yaffs2.c flash.o usb.o
cmd_dtt.c cmd_load.o cmd_reginfo.c command.c hush.c usb_storage.c
cmd_echo.c cmd_log.c cmd_reginfo.o command.o hush.o xyzModem.c
cmd_echo.o cmd_mac.c cmd_reiser.c console.c hwconfig.c xyzModem.o
cmd_eeprom.c cmd_mem.c cmd_sata.c console.o image.c
cmd_elf.c cmd_mem.o cmd_scsi.c ddr_spd.c image.o
cmd_elf.o cmd_mfsl.c cmd_setexpr.c decompress_ext4.c iomux.c
cmd_exit.c cmd_mgdisk.c cmd_sf.c decompress_ext4.o kallsyms.c
每一个命令都由 U_BOOT_CMD 宏描述，宏定义的位置在 include/command.h 文件中，感兴趣的小伙伴可以去研究下。
user@vmware:~/tiny4412/FriendlyARM.uboot-2010.12$ grep -rsnE " U_BOOT_CMD("
include/command.h:112:#define U_BOOT_CMD(name,maxargs,rep,cmd,usage,help) \
include/command.h:120:#define U_BOOT_CMD(name,maxargs,rep,cmd,usage,help) \
doc/README.commands:5:Then using the U_BOOT_CMD() macro to fill in a cmd_tbl_t struct.
二 分析 help 命令
这里我们分析下 help 命令来了解 uboot 命令的结构。common/cmd_help.c 文件内容如下：
#include <common.h>
#include <command.h>
extern cmd_tbl_t __u_boot_cmd_bdinfo;
extern cmd_tbl_t __u_boot_cmd_showvar;
int do_help(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
{
return _do_help(&__u_boot_cmd_bdinfo,
&__u_boot_cmd_showvar - &__u_boot_cmd_bdinfo + 1,
cmdtp, flag, argc, argv);
}
U_BOOT_CMD(
help, CONFIG_SYS_MAXARGS, 1, do_help,
"print command description/usage",
"\n"
" - print brief description of all commands\n"
"help command ...\n"
" - print detailed usage of 'command'"
);
/* This does not use the U_BOOT_CMD macro as ? can't be used in symbol names */
cmd_tbl_t __u_boot_cmd_question_mark Struct_Section = {
"?", CONFIG_SYS_MAXARGS, 1, do_help,
"alias for 'help'",
#ifdef CONFIG_SYS_LONGHELP
""
#endif /* CONFIG_SYS_LONGHELP */
};
三 编写一个自定义的 hello 命令
从 help 命令的实现，猜测实现一个新的 uboot cmd 的步骤为：
- 在 common 目录下创建 cmd_hello.c 文件
包含头文件
#include <common.h> #include <command.h>使用 U_BOOT_CMD 定义一个命令
U_BOOT_CMD ( <命令的名称>, <最大参数个数>, <重复次数>, <命令底层执行的回调函数>, <说明命令的功能>, <说明命令的详细用法> );实现回调函数
函数原型为/** * @param cmdtp 描述命令的结构体，保存了 U_BOOT_CMD * @param flag * @param argc 命令传入的参数的个数 * @param argv 命令传入的参数 */ int do_help(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
四 编译 uboot 命令
- 将实现的 cmd_hello.c 放到 common 目录下
修改 Makefile，将 cmd_hello.c 包含到到编译系统中
user@vmware:~/tiny4412/FriendlyARM.uboot-2010.12$ git diff diff --git a/common/Makefile b/common/Makefile old mode 100644 new mode 100755 index bfa39d5..92b9a66 --- a/common/Makefile +++ b/common/Makefile @@ -48,6 +48,7 @@ COBJS-y += cmd_bootm.o COBJS-y += cmd_help.o COBJS-y += cmd_nvedit.o COBJS-y += cmd_version.o +COBJS-y += cmd_hello.o # environment COBJS-y += env_common.o重新编译
下载验证
TINY4412 # hello xxx hello - this is a demo command Usage: hello - this is a demo long help TINY4412 # hello hello uboot
