1、今天在调试freescale开发板，因为其他同事用过拿到手后就出现以下问题。
VFS: Cannot open root device "mmcblk0p1" or unknown-block(179,1)
Please append a correct "root=" boot option; here are the available partitions:1f00 256 mtdblock0 (driver?)1f01 3840 mtdblock1 (driver?)b300 3872256 mmcblk0 driver: mmcblk b301 3868160 mmcblk0p1Kernel panic – not syncing: VFS: Unable to mount root fs on unknown-block(179,1)[<8002e4c0>] (unwind_backtrace+0x0/0xf0) from [<80375504>] (panic+0x6c/0xe0)[<80375504>] (panic+0x6c/0xe0) from [<80008d90>] (mount_block_root+0x258/0x2a8)[<80008d90>] (mount_block_root+0x258/0x2a8) from [<80008f5c>] (prepare_namespace+0x11c/0x174)[<80008f5c>] (prepare_namespace+0x11c/0x174) from [<80008480>] (kernel_init+0x120/0x168)
[<80008480>] (kernel_init+0x120/0x168) from [<8002a9c0>] (kernel_thread_exit+0x0/0x8)
2、一直是上述问题，说明找不到”mmcblk0p1“分区，调试了一会也没有任何解决的迹象。
3、拔下SD卡发现是SD卡写保护了，导致kernel无法挂载mmcblk0p1分区
4、把SD卡写保护去掉系统就运行正常了。
哪里有意志存在，哪里就会有出路。
