pstore_ramoops

https://wenku.baidu.com/view/6d55bb48195f312b3169a5e2.html

当板子panic时，怎么查看宕机前的log，找到出错的函数

比如手动使系统崩溃：
 echo c > /proc/sysrq-trigger
 
 或是其他的错误使系统panic
 
然后，切记！使板子重启要用

fastboot reboot

然后
cd /sys/fs/pstore
ls
会看到几个log文件，比如
hikey960:/sys/fs/pstore # ls
console-ramoops-0 dmesg-ramoops-0 dmesg-ramoops-1

然后
cat console-ramoops-0
就可以看到log内容了

比如
[   73.531139] [<ffffff800861d088>] sysrq_handle_crash+0x28/0x34
[   73.531145] [<ffffff800861d66c>] __handle_sysrq+0x12c/0x19c
[   73.531148] [<ffffff800861dad8>] write_sysrq_trigger+0x68/0x78
[   73.531159] [<ffffff80082d15e4>] proc_reg_write+0x88/0xf4
[   73.531169] [<ffffff80082565d0>] vfs_write+0xb4/0x1d8
[   73.531172] [<ffffff80082567f8>] SyS_write+0x54/0xb0
[   73.531181] [<ffffff8008083730>] el0_svc_naked+0x24/0x28
[   73.531185] Code: 52800020 b906f820 d5033e9f d2800001 (39000020)
[   73.531193] ---[ end trace 90f4cede703e7770 ]---
[   73.543171] Kernel panic - not syncing: Fatal exception
[   73.543177] SMP: stopping secondary CPUs
[   73.546078] Kernel Offset: disabled
[   73.546081] Memory Limit: none
[   74.923899] Rebooting in 5 seconds..

打印了系统panic前的log