Thursday, November 13, 2014

Can't change screen resolution of Android-x86_64 installed in UEFI mode


I previously used vga=ask and vga= in Android-x86 6.0 to set the display resolution in VMWare and now in QEMU/KVM.


Now I downloaded and installed Android-x86_64 (CyanogenMod 13), in QEMU, in UEFI mode, to a GPT partition, and the option doesn't seem to work anymore. Instead it outputs:



error: invalid file name 'vga=ask'



There doesn't appear to be much information about this elsewhere. But I could find:




I tried wm size 1280x720 (in terminal emulator as root) and it kind of works. the resolution appears to change, but the display area doesn't and it becomes a pain to read anything. So I had it reverted with wm size reset.


I also tried UVESA_MODE=1280x720 and it also reports "invalid filename 'UVESA_MODE'".


There's a proposed solution at the 3rd link (debug.drm.mode.force 1280x720) but it also didn't work.


So, how to change the screen resolution properly?


[Update] I tried on a new installation and the vga kernel option works in non-UEFI mode.



Answer



I got it.


Short answer: This line should go in the bootloader for UEFI mode:


set gfxpayload=1280x720


Explanation:



On x86 systems, the kernel will be booted using the 32-bit boot protocol. Note that this means that the ‘vga=’ boot option will not work; if you want to set a special video mode, you will need to use GRUB commands such as set gfxpayload=1024x768 or set gfxpayload=keep (to keep the same mode as used in GRUB) instead. (...) The linux16 command (see linux16) avoids this restriction.


GNU GRUB Manual 2.02: linux



See also, How Do You Pass VGA/VESA Modes with GRUB2? (Unix.SE).


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