Uboot支持的命令
在uboot终端下输入 ? 号即可查看当前uboot支持的所有 命令
=> ? ? - 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' bootm - boot application image from memory bootr - boot application image from memory chpart - change active partition cmp - memory compare colorbar- show colorbar coninfo - print console devices and information cp - memory copy crc32 - checksum calculation disp - show display status echo - echo args to console editenv - edit environment variable efex - run to efex env - environment handling commands erase - erase FLASH memory fastboot- fastboot - enter USB Fastboot protocol fatinfo - print information about filesystem fatload - load binary file from a dos filesystem fatls - list files in a directory (default /) fatsize - determine a file's size fatwrite- write file into a dos filesystem fdt - flattened device tree utility commands flinfo - print FLASH memory information gpt - GUID Partition Table help - print command description/usage i2c - I2C sub-system itest - return true/false on integer compare loadb - load binary file over serial line (kermit mode) loads - load S-Record file over serial line loadx - load binary file over serial line (xmodem mode) loady - load binary file over serial line (ymodem mode) logo - show default logo loop - infinite loop on address range md - memory display memtester- start application at address 'addr' mm - memory modify (auto-incrementing address) mmc - MMC sub system mmcinfo - display MMC info mtdparts- define flash/nand partitions mw - memory write (fill) nm - memory modify (constant address) part - disk partition related commands pbread - read data from private data printenv- print environment variables protect - enable or disable FLASH write protection pst - read data from secure storageerase flag in secure storage reset - Perform RESET of the CPU run - run commands in an environment variable saveenv - save environment variables to persistent storage set_working_fdt- set_working_fdt fdt_addr setenv - set environment variables setexpr - set environment variable as the result of eval expression sleep - delay execution for some time source - run script from memory sprite_test- do a sprite test sunxi_bmp_info- manipulate BMP image data sunxi_bmp_show- manipulate BMP image data sunxi_card0_probe- probe sunxi card0 device sunxi_dma- do dma test sunxi_flash- sunxi_flash sub-system sunxi_so- sunxi_so sub-system timer_test- do a timer and int test timer_test1- do a timer and int test ubi - ubi commands ubifsload- load file from an UBIFS filesystem ubifsls - list files in a directory ubifsmount- mount UBIFS volume ubifsumount- unmount UBIFS volume uburn - do a burn from boot version - print monitor, compiler and linker version
Fat 命令说明
fat命令可以对 FAT 文件系统的相关存储设备进行查询及文件读写操作,在打包固件的时候, 我们会制作启动资源分区镜像, 把指定的目录下的文件按照文件系统的格式排布,文件中包括了原来目录中的所有文件,并完全按照目录结构排列。当把这个镜像文件烧写到存储设备上的某一个分区的时候,可以看到这个分区和原有目录的内容一样。使用fat可以方便地以文件和目录的方式对小机 flash 进行数据访问,如显示 logo。这些指令基本上要和 U 盘或者 SD 卡同时使用,主要用于读取这些移动存储器上的 FAT 分区。其相关操作命令如下:
fatls
列出相应设备目录上的所有文件,示例如下图:
补充说明,fatls mmc 2:2 中的第一个 2 表示的是 emmc 设备,2 表示其分区号,其说明如下图:
fatinfo
打印出相应设备目录的文件系统信息,示例如下图:
fatload
从 FAT 文件系统中读取二进制文件到 RAM 存储中,示例如下:
sunxi#usb start (Re)start USB... USB0: start sunxi ehci1... config usb pin success config usb clk ok sunxi ehci1 init ok... USB EHCI 1.00 scanning bus 0 for devices... 3 USB Device(s) found scanning usb for storage devices... 1 Storage Device(s) found sunxi#fatls usb 0:1 / 16024600 sandisksecureaccessv3_win.exe sandisk secureaccess/ lost.dir/ Android/ test/ video test/ amapauto/ 0 vid_20161017_160818.ts phoenixsuit/ system volume information/ 0 vid_20161017_160919.ts video/ 156672 wifi pro_com su.exe 495 sys.ini 1035 pr_80211g_all.ini config/ 158208 wifi pro_new.exe 158208 wifi pro.exe 0 vid_20161017_164822.ts 0 vid_20161017_164906.ts sunxi-tvd/ 71149 sys_config.fex vga/ 397836884 system.img 14180352 boot.img 13 file(s), 13 dir(s) sunxi#fatload usb 0:1 0x42000000 boot.img reading boot.img 14180352 bytes read in 1149 ms (11.8 MiB/s) sunxi#mmc dev 2 mmc2(part 0) is current device sunxi#mmc write 0x42000000 0x15000 5000 MMC write: dev # 2, block # 86016, count 20480 ... 20480 blocks written: OK
说明:以上操作即将 U 盘的boot.img写到对应的 mmc 分区地址处。
- fatwrite: 从内存中将对应的文件写到设备文件系统中。
md 命令说明
md命令可以对指定内存的数据进行查看,方便了解内存的数据情况及调试工作。其使用方法如下:
md 0xF0000000: 即用md命令查看内存DRAM 0xF0000000处内容
获取更多嵌入式干货,请关注威信baiwenkeji