Hi, On Fri Sep 06, 2019 at 14:15:00 +0700, Adi Lima wrote:

I've been trying to make this one work, but in vain, so far... Either using qemu or in real hardware, all failed when booting from UEFI.

...

From qemu's stdio I know that the boot has been completed successfuly, but it seems like fb-drv was unable to support current default mode from EFI Framebuffer boot (or it is trying to switch to some other mode, and failed?).

I was using standard ex_fb_spectrum_cc, with x86-fb.io, x86-fb.cfg and x86-legacy.devs, all loaded by grub2 as Multiboot2 and Module2

Everything was fine if booted using BIOS, but I haven't try on UEFI mode with CSM.

I believe this has nothing to do with UEFI vs. CSM but...

Can you give me a hint of what to try next, please?

fbdrv | Trying execution of ``set VBE mode'' using x86emu fbdrv | Found VESA BIOS version 3.0 fbdrv | OEM QEMU fbdrv | Scanning for 'best' possible mode: fbdrv | Trying to read DDC info fbdrv | DDC function not supported fbdrv | EDID not available (-19), finding best possible mode ... fbdrv | Mode: 0xf1 1024x768@32, RGB: 16(8):8(8):0(8) mode: bb fbdrv | Could not find suitable mode fbdrv | Failed to setup Framebuffer

It finds at least one possible mode but the auto selection is not very "smart" in this case. Please try to add -m 0xf1 to fb-drv command line in the x86-fb.cfg. Does this help? Adam