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: - What happened to vga=ask in newer kernels? (Unix.SE) - Grub: Legacy 'ask' parameter no longer supported (Superuser) - android-x86_64-5.1-rc1.img --- change resolution (Android-x86 at Google Groups) 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 url (debug.drm.mode.force 1280x720) but it also didn't work. So, how to change the screen resolution properly? **[Update]** I tested with a new, non-UEFI installation and the vga kernel option works there.