loongson-2F 不能升级到 Debian Stretch

昨天本想把openjdk更新到8版本，Debian jessie不包含，所以就想升级到Stretch，结果升级后，我发现vim不能用了,提示illegal instruct,最后连bash都不能使用。经过搜索，我发现 Debian Stretch 的mips port已经不支持 loongson 2F,因为更新了指令集

https://www.debian.org/releases/stretch/mips/release-notes/ch-information.en.html

5.1.7. 32-bit MIPS now requires an R2 processor

The 32-bit MIPS support (both big- and little- endian) now requires a processor supporting MIPS32 Release 2 of the MIPS instruction set. Notably the Loongson-2E/2F and systems based on them (including the Yeeloong laptop) are no longer supported.

The following shell script can be used to indicate if your machine supports R2 (assuming only one type of processor is present). Note that Loongson-3 processors are supported even though they only claim to support MIPS32 Release 1.

还好原来的loongson自带的系统还在，通过debootstrap重新安装。记录下操作步骤

1. 将root分区 /dev/sdax挂载到/mnt下

2. 执行 debootstrap --arch=mipsel wheezy /mnt http://ftp.cn.debian.org/debian/

3. 步骤2正常结束后，chroot /mnt，更改root的password,更新fstab及其它配置,apt-get update,apt-get install linux-image-xxx

参考：https://wiki.debian.org/Debootstrap