有时候u-boot的环境变量需要在烧录后再设置,在烧录之后都会有一些默认的环境变量比如bootarg等,如果在编译u-boot之前就把自己需要的变量设置好,烧录的时候直接就得到自己想要的变量,这在量产中是很方便的。
在哪里配置呢?找到了,在这里include/configs/<你的板子名称>.h,如include/configs/mx6dl_sabresd.h,环境变量的部分配置如下:
#define CONFIG_EXTRA_ENV_SETTINGS
"netdev=eth0 "
"ethprime=FEC0 "
"uboot=u-boot.bin "
"kernel=uImage "
"nfsroot=/opt/eldk/arm "
"bootargs_base=setenv bootargs console=ttymxc0,115200 "
"bootargs_nfs=setenv bootargs ${bootargs} root=/dev/nfs "
"ip=dhcp nfsroot=${serverip}:${nfsroot},v3,tcp "
"bootcmd_net=run bootargs_base bootargs_nfs; "
"tftpboot ${loadaddr} ${kernel}; bootm "
"bootargs_mmc=setenv bootargs ${bootargs} ip=dhcp "
"root=/dev/mmcblk0p1 rootwait "
"bootcmd_mmc=run bootargs_base bootargs_mmc; "
"mmc dev 3; "
"mmc read ${loadaddr} 0x800 0x2000; bootm "
"bootcmd=run bootcmd_net "