[RK3399][Android7.1] 调试笔记 --- 查看开机上一次kernel log

OS: Android 7.1

Kernel: v4.4.83

rk3288平台，rk自己实现了一套机制获取上一次的kernel log.

rk3399平台，使用了内核框架中的ramoops机制。

查看方法：

#cat /sys/fs/pstore/console-ramoops-0

要开启此功能，需要做以下几点配置(rk3399默认都开启了)

打开功能：

rockchip_defconfig:

CONFIG_PSTORE=yCONFIG_PSTORE_CONSOLE=yCONFIG_PSTORE_PMSG=yCONFIG_PSTORE_RAM=y

驱动对应路径：

kernel/fs/pstore

配置内存地址以及各个功能size

rk3399-android.dtsi:

ramoops_mem: ramoops_mem {reg = <0x0 0x110000 0x0 0xf0000>;reg-names = "ramoops_mem";};ramoops {compatible = "ramoops";record-size = <0x0 0x20000>;console-size = <0x0 0x80000>;ftrace-size = <0x0 0x00000>;pmsg-size = <0x0 0x50000>;memory-region = <&ramoops_mem>;};

各个property意义：

- compatible: must be "ramoops"- memory-region: phandle to a region of memory that is preserved between rebootsOptional properties:- ecc-size: enables ECC support and specifies ECC buffer size in bytes (defaults to no ECC)- record-size: maximum size in bytes of each dump done on oops/panic (defaults to 0)- console-size: size in bytes of log buffer reserved for kernel messages (defaults to 0)- ftrace-size: size in bytes of log buffer reserved for function tracing and profiling (defaults to 0)- pmsg-size: size in bytes of log buffer reserved for userspace messages (defaults to 0)- unbuffered: if present, use unbuffered mappings to map the reserved region (defaults to buffered mappings)- no-dump-oops: if present, only dump panics (defaults to panics and oops)

开机后做mount:

system/core/rootdir/init.rc:

# pstore/ramoops previous console logmount pstore pstore /sys/fs/pstorechown system log /sys/fs/pstore/console-ramoopschmod 0440 /sys/fs/pstore/console-ramoopschown system log /sys/fs/pstore/pmsg-ramoops-0chmod 0440 /sys/fs/pstore/pmsg-ramoops-0

参考：

ramoops&pstore简要说明