根文件系统制作 -- Kernel panic - not syncing

目标环境： Embedded Linux

系统版本： linux-2.6.35.3

GUI版本： QtEmbedded-4.8.5-arm

问题描述：

 

UBIFS: mounted UBI device 0, volume 0, name "rootfs0"
UBIFS: file system size:   106786816 bytes (104284 KiB, 101 MiB, 841 LEBs)
UBIFS: journal size:       5332992 bytes (5208 KiB, 5 MiB, 42 LEBs)
UBIFS: media format:       w4/r0 (latest is w4/r0)
UBIFS: default compressor: lzo
UBIFS: reserved for root:  4952683 bytes (4836 KiB)
VFS: Mounted root (ubifs filesystem) on device 0:15.
Freeing init memory: 160K

Kernel panic - not syncing: No init found.  Try passing init= option to kernel. See Linux Documentation/init.txt for guidance.
Backtrace:
[<c0034468>] (dump_backtrace+0x0/0x114) from [<c03cfea0>] (dump_stack+0x18/0x1c)
r7:00000013 r6:c0050170 r5:c0028e84 r4:c053f338
[<c03cfe88>] (dump_stack+0x0/0x1c) from [<c03cff1c>] (panic+0x78/0xf4)
[<c03cfea4>] (panic+0x0/0xf4) from [<c00305ec>] (init_post+0xb4/0xdc)
r3:00000000 r2:c752c300 r1:c752c400 r0:c0483252
[<c0030538>] (init_post+0x0/0xdc) from [<c00084fc>] (kernel_init+0x12c/0x170)
r5:c0028e84 r4:c053e460
[<c00083d0>] (kernel_init+0x0/0x170) from [<c0050170>] (do_exit+0x0/0x6dc)
r5:c00083d0 r4:00000000

分析：

            对照自带根文件系统， 无 不合理的地方

           #sudo tar         // 提升权限重新打包 根文件系统

结果：

            重新下载固件， 运行正常

UBIFS: mounted UBI device 0, volume 0, name "rootfs0"
UBIFS: file system size: 106786816 bytes (104284 KiB, 101 MiB, 841 LEBs)
UBIFS: journal size: 5332992 bytes (5208 KiB, 5 MiB, 42 LEBs)
UBIFS: media format: w4/r0 (latest is w4/r0)
UBIFS: default compressor: lzo
UBIFS: reserved for root: 4952683 bytes (4836 KiB)
VFS: Mounted root (ubifs filesystem) on device 0:15.
Freeing init memory: 160K

starting pid 1140, tty '': '/etc/rc.d/rcS'
Mounting /proc and /sys
Starting the hotplug events dispatcher udevd
Synthesizing initial hotplug events
Setting the hostname to myzr
Mounting filesystems
Generating keys for the ssh server:
Starting the ssh server:
Setting up networking on loopback device:
Setuping the eth0: 192.168.3.104
eth0: Freescale FEC PHY driver [Gen

原因：

             部分文件访问需要 root 权限， 普通用户身份打包会遗漏部分文件， 关键文件的缺少导致系统起不来。