debian 9 install questions

question

/sys/kernel/debug/vgaswitcheroo/switch: No such file or directory

answer

1. cat /sys/kernel/debug/vgaswitcheroo/switch address:https://bbs.archlinuxcn.org/viewtopic.php?id=2993,

2. https://help.ubuntu.com/community/HybridGraphics,

3. https://askubuntu.comquestions/648426/discrete-graphics-always-dynoff

question

ERROR radeon kernel modesetting for R600 or later requires firmware-amd-graphics.

answer

1. add /etc/apt/sources.list deb http://ftp.us.debian.org/debian/ testing main non-free contrib

2. deb-src http://ftp.us.debian.org/debian/ testing main non-free contrib

3. sudo apt-get update

4. sudo apt-get install firmware-amd-graphics

question

grub rescue

answer

1. ls

2. ls (hd0,x)/boot/grub or (hd1,x)/boot/grub

3. set root=(hd0,5)

4. set prefix=(hd0,5)/boot/grub

5. set insmod /boot/grub

6. set insmod /boot/grub

7. sudo update-grub

8. sudo grub-install /dev/sda