請問如何修改uboot 讓kernel 開機可以自動載入ramdisk??？

可以参考以下命令，
fatload mmc 0 $loadaddr uImage
fatload mmc 0 $rdaddr ramdisk.gz
setenv bootargs console=ttyO0,115200n8 root=/dev/ram0 rw initrd=$rdaddr,64M
bootm

Dear Blaider
1.請問這些命令是要加再uboot 哪邊??

2.或是有uenv.txt 可以參考??

3.我看am335x_evm.h 的CONFIG_EXTRA_ENV_SETTINGS
    已經有你列出的命令,請問要如何修改呢??
   (我現在都會固定從mmc 抓取rootfs 然後抓不到)


#define CONFIG_EXTRA_ENV_SETTINGS
"loadaddr=0x80200000"
"kloadaddr=0x80007fc0"
"fdtaddr=0x80F80000"
"fdt_high=0xffffffff"
"rdaddr=0x81000000"
"bootfile=uImage"
"fdtfile="
"console=ttyO0,115200n8"
"optargs="
"mtdids=" MTDIDS_DEFAULT ""
"mtdparts=" MTDPARTS_DEFAULT ""
"dfu_alt_info_mmc=" DFU_ALT_INFO_MMC ""
"dfu_alt_info_emmc=rawemmc mmc 0 3751936"
"dfu_alt_info_nand=" DFU_ALT_INFO_NAND ""
"mmcdev=0"
"mmcroot=/dev/mmcblk0p2 ro"
"mmcrootfstype=ext3 rootwait"
"nandroot=ubi0:rootfs rw ubi.mtd=7,2048"
"nandrootfstype=ubifs rootwait=1"
"nandsrcaddr=0x280000"
"nandimgsize=0x500000"
"rootpath=/export/rootfs"
"nfsopts=nolock"
"static_ip=$[ipaddr]:$[serverip]:$[gatewayip]:$[netmask]:$[hostname]"
"::off"
"ramroot=/dev/ram0 rw ramdisk_size=65536 initrd=$[rdaddr],64M"
"ramrootfstype=ext2"
"ip_method=none"
"bootargs_defaults=setenv bootargs "
"console=$[console] "
"$[optargs]"
"mmcargs=run bootargs_defaults;"
"setenv bootargs $[bootargs] "
"root=$[mmcroot] "
"rootfstype=$[mmcrootfstype] ip=$[ip_method]"
"nandargs=setenv bootargs console=$[console] "
"$[optargs] "
"root=$[nandroot] "
"rootfstype=$[nandrootfstype]"
"spiroot=/dev/mtdblock4 rw"
"spirootfstype=jffs2"
"spisrcaddr=0xe0000"
"spiimgsize=0x362000"
"spibusno=0"
"spiargs=setenv bootargs console=$[console] "
"$[optargs] "
"root=$[spiroot] "
"rootfstype=$[spirootfstype]"
"netargs=setenv bootargs console=$[console] "
"$[optargs] "
"root=/dev/nfs "
"nfsroot=$[serverip]:$[rootpath],$[nfsopts] rw "
"ip=dhcp"
"bootenv=uEnv.txt"
"loadbootenv=fatload mmc $[mmcdev] $[loadaddr] $[bootenv]"
"importbootenv=echo Importing environment from mmc ...; "
"env import -t $loadaddr $filesize"
"ramargs=setenv bootargs console=$[console] "
"$[optargs] "
"root=$[ramroot] "
"rootfstype=$[ramrootfstype]"
"loadramdisk=fatload mmc $[mmcdev] $[rdaddr] ramdisk.gz"
"loaduimagefat=fatload mmc $[mmcdev] $[kloadaddr] $[bootfile]"
"loaduimage=ext2load mmc $[mmcdev]:2 $[kloadaddr] /boot/$[bootfile]"
"mmcboot=echo Booting from mmc ...; "
"run mmcargs; "
"bootm $[kloadaddr]"
"nandboot=echo Booting from nand ...; "
"run nandargs; "
"nand read $[loadaddr] $[nandsrcaddr] $[nandimgsize]; "
"bootm $[loadaddr]"
"spiboot=echo Booting from spi ...; "
"run spiargs; "
"sf probe $[spibusno]:0; "
"sf read $[loadaddr] $[spisrcaddr] $[spiimgsize]; "
"bootm $[loadaddr]"
"netboot=echo Booting from network ...; "
"setenv autoload no; "
"dhcp; "
"tftp $[loadaddr] $[bootfile]; "
"run netargs; "
"bootm $[loadaddr]"
"ramboot=echo Booting from ramdisk ...; "
"run ramargs; "
"bootm $[loadaddr]"
"findfdt="
"if test $board_name = A335BONE; then "
"setenv fdtfile am335x-bone.dtb; fi; "
"if test $board_name = A33515BB; then "
"setenv fdtfile am335x-evm.dtb; fi; "
"if test $board_name = A335X_SK; then "
"setenv fdtfile am335x-evmsk.dtb; fi"

  bootcmd= run loaduimagefat;run loadramdisk;run ramargs;bootm;

简单点就是修改一下bootcmd变量，让它自动运行
bootcmd= run loaduimagefat;run loadramdisk;run ramargs;bootm $[kloadaddr];

可以参考我们wiki上的guide：
http://processors.wiki.ti.com/index.php/Creating_a_Root_File_System_for_Linux_on_OMAP35x
http://processors.wiki.ti.com/index.php/Creating_a_RAMDISK

Dear Jian
ramdisk我早已經建好了
我是問要如何透過uEnv.txt 或是修改uboot 程式
使其可以 自動將SD卡boot 分區內的ramdisk.gz 自動mount 當作root file system 

参考过下面这个guide列出来的步骤和参数吗，可以从NAND或者SD卡启动ramdisk：
http://processors.wiki.ti.com/index.php/AM335x_U-Boot_User%27s_Guide#Environment_Settings_for_Ramdisk