Klemens Nanni [k...@openbsd.org] wrote: > On Sun, May 07, 2023 at 06:22:55PM +0200, Mark Kettenis wrote: > > > Date: Sat, 6 May 2023 22:47:55 +0000 > > > From: Klemens Nanni <k...@openbsd.org> > > > > > > On Sat, Apr 29, 2023 at 06:47:48PM +0000, Klemens Nanni wrote: > > > > Installing to a wiped disk on EFI machines suggests MBR not GPT when > > > > chosing > > > > (E)dit because MBR vs. GPT in this manual case is picked based on > > > > existing > > > > data on the disk, not whether it has EFI. > > > > > > > > Fix that so users get correct instructions and don't end up with legacy > > > > partitioning in fresh installs on new machines. > > > > > > > > Feedback? OK? > > > > > > Anyone? > > > > > > Put differently, in the manual (E)dit case, the guidance message should > > > be oriented towards the actual system (this diff) and not whatever is on > > > the disk that's about to be set up by hand (-current). > > > > Makes no sense to me. If you choose (E)dit, you want to make changes > > to the partition table that is already on the disk. > > If the disk has random garbage or you zero it, the (E)dit case looks for GPT > which is not there and then suggests to to MBR instead. > > > EFI firmware doesn't really care whether you have a GPT partition > > table or a traditional MBR partition table. > > That might work, but shouldn't you go for GPT with an ESP on UEFI systems? > > In the case I describe and hit, our installer advises to just create an MBR > with one OpenBSD partition, whereas I think we should rather hint users at GPT > with ESP and an OpenBDS partition on UEFI systems. >
I don't quite understand the case this patch solves, because my installs to fresh media always get EFI/GPT. It doesn't default to MBR. However, if there is a case where it tries to use MBR, that isn't going to work so well. MBR boot is totally unsupported on modern Intel. Starting with 10th gen Intel processors, Intel only supplies graphics code for EFI mode. With some 10th gen chipsets, like W480, the BIOS still gives you can option to boot MBR with zero graphics. For the BIOS on 11th gen chipsets like the W580, there is no MBR boot capability at all, for whatever reason.
