Dear all,
My board is BBB. I have built the u-boot and kernel and copy the images into SD card. Also I download the official rootfs, but its’ size is large, 2xxM bytes. I am trying to make a small one. My target is to boot up linux from SD card by manual method. So I key in some commands in the U-Boot Console as below,
fatload mmc 0:1 0x80200000 zImage
fatload mmc 0:1 0x80f00000 am335x-boneblack.dtb
fat load mmc 0:1 0x81000000 uRamdisk
setenv bootargs console=ttyS0,115200 initrd=/bin/sh
bootz 0x80200000 0x81000000 0x80f00000
in the .config of KERNEL, I enable some setting as below,
CONFIG_BLK_DEV_INITRD=y
CONFIG_BLK_DEV_RAM=y
CONFIG_DEV_RAM_COUNT=4
CONFIG_DEV_RAM_SIZE=32768
Some of my boot-up log
[ 0.436868] initrd_start[0x6aad8ae16aad8ae1]
[ 0.436878] Trying to unpack rootfs image as initramfs…
[ 0.437947] Detected gzip compressed data
[ 0.437954] unpack_to_rootfs 501
[ 0.617054] populate_rootfs 643
[ 0.619786] Freeing initrd memory: 2700K (Note: I just make a small rootfs, create some folders and copy the systemd from offical rootfs into it)
[ 2.542175] VFS: Cannot open root device “(null)” or unknown-block(0,0): error -6
[ 2.549837] Please append a correct “root=” boot option; here are the available partitions:
[ 2.558276] 0100 32768 ram0
[ 2.558282] (driver?)
[ 2.564465] 0101 32768 ram1
[ 2.564469] (driver?)
[ 2.570627] 0102 32768 ram2
[ 2.570630] (driver?)
[ 2.576787] 0103 32768 ram3
[ 2.576790] (driver?)
[ 2.582932] b300 30228480 mmcblk0
[ 2.582936] driver: mmcblk
[ 2.589784] b301 1024000 mmcblk0p1 92439f51-01
[ 2.589788]
[ 2.596635] b302 29203456 mmcblk0p2 92439f51-02
[ 2.596639]
[ 2.603475] b308 3735552 mmcblk1
[ 2.603480] driver: mmcblk
[ 2.610340] b309 3731456 mmcblk1p1 f26b5473-01
[ 2.610343]
[ 2.617192] b320 512 mmcblk1rpmb
[ 2.617195] (driver?)
[ 2.623946] b318 2048 mmcblk1boot1
[ 2.623950] (driver?)
[ 2.630787] b310 2048 mmcblk1boot0
[ 2.630790] (driver?)
[ 2.637639] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
My question is:
- Should I set root=xxx in the bootargs ? Is the commands in U-boot console enough?
- I have blocked in this problem many days, Anyone is able give me a hint?
I am appreciate your suggestion and hint. thanks a lot.