baudrate=115200 
bootargs=console=ttySAC0,115200 root=/dev/mmcblk0p2 rw rootfstype=ext3 rootwait
bootcmd=if mmc rescan ${mmcdev}; then if run loadbootscript; then run bootscript; else if run loaduimage; then run mmcboot; else run nandboot; fi; fi; else run nandboot; fi
bootdelay=10
bootfile=uImage
bootscript=echo Running bootscript from mmc ...; source ${loadaddr}
console=ttyO0,115200n8
dieid#=4b1c00029ff80000016842c91103201f
ethact=smc911x-0
ethaddr=00:50:c2:d9:d0:c6
filesize=301E54
loadaddr=0x82000000
loadbootscript=fatload mmc ${mmcdev} ${loadaddr} boot.scr
loaduimage=fatload mmc ${mmcdev} ${loadaddr} uImage
mmcargs=setenv bootargs console=${console} root=/dev/mmcblk0p2 rw rootfstype=ext3 rootwait
mmcboot=echo Booting from mmc ...; run mmcargs; bootm ${loadaddr}
mmcdev=0
nand_kernel= nand read.i 0x80007fc0 280000 380000;echo 222222...;
nand_mmc_boot= nandecc hw 2;echo 111111...; run nand_kernel;run nandargs ; bootm 0x80007fc0
nandargs=echo 333333...; setenv bootargs console=ttySAC0,115200 root=/dev/mmcblk0p2 rw rootfstype=ext3 rootwait
nandboot=echo Booting from nand ...; run nandargs; onenand read ${loadaddr} 280000 400000; bootm ${loadaddr}
nandcargs=echo 333333...;setenv bootargs console=ttySAC0,115200 root=/dev/mmcblk0p2 rw rootfstype=ext3 rootwait
stderr=serial
stdin=serial
stdout=serial
usbtty=cdc_acm

uboot 信息解读