>>>>>> I've made a couple of dual legacy-bios/uefi boot usb sticks using >>>>>> grub-2.00. >>>>>> >>>>>> Both of the usb sticks will uefi boot linux, but there appears to be a >>>>>> problem with legacy-bios boot of linux. >>>>>> >>>>>> One of the usb sticks gives an "invalid partition table!" error >>>>>> >>>>> What displays the message ? GRUB or the BIOS firmware ? Do you get the >>>>> GRUB rescue prompt ? >>>>> Some BIOS firmwares require that a primary partition has the boot flag. >>>>> >>>> It seems as though it is grub displaying the message. >>>> >>>> In one case I get the "invalid partition table!" message and have to >>>> cycle the power >>>> >>> If the message was displayed by GRUB, I believe that you would at least get >>> the GRUB rescue prompt. >>> >> After videoing the screen, I see that the error message is: >> >> Error: file '/EFI/BOOT/grub/i386-pc/efi_gop.mod' not found >> Error: no suitable video modes found >> >> efi_gop* is in i386-efi and x86_64-efi, but not in i386-pc. >> > Which is correct, this video driver is available on EFI platform only. > >> If I add "vga=792" then grub gives an error message that this is depreciated, >> but the frame buffer is set to 1024x768. If I try "vga=895" the native >> resolution of 1366x768 >> is not set even though it is present in "Xvesa -listmodes" and is set with >> uefi boot. >> > It is not clear what "is not set" means here (is not set in grub or in > Linux), but your grub.cfg > in original post does not load any video driver for for legacy BIOS. > > In current grub you can simply use "insmod all_video" which will attempt to > load all > available video drivers. Usually only one of them actually works. This should > handle both legacy BIOS and EFI. > "insmod all_video" did the trick and I finally get 1366x768 with a legacy-bios boot - thanks for this :)
$ dmesg | grep fb ... vesafb: mode is 1366x768x32, linelength=5504, pages=0 vesafb: scrolling: redraw vesafb: Truecolor: size=8:8:8:8, shift=24:16:8:0 vesafb: framebuffer at 0xe0000000, mapped to 0xffffc90000800000, using 4160k, total 4160k fb0: VESA VGA frame buffer device With a legacy-bios boot several seconds pass before the grub menu comes up, which I guess is grub trying the video drivers one by one. Is there a way to tell which video driver was used - other than trying them one by one? _______________________________________________ Help-grub mailing list [email protected] https://lists.gnu.org/mailman/listinfo/help-grub
