On Wed, Dec 3, 2025 at 1:56 PM <[email protected]> wrote: > If I can successfully boot from media with a live amd64 system, > then does that prove I can install amd64? > > The media that I boot from might be: > 1. A usb flash drive with: > a. A live system > b. An installXX.img > 2. cdXX.iso > 3. bsd.rd, booted from 'boot hd0a:/bsd.rd' on i386 install. > That is, I am booting the bsd.rd for amd64, not the one for i386. >
Up though OpenBSD 7.3 it was common to be able to boot the amd64 bsd.rd from an i386 USB drive (i.e. you could install i386 on a USB drive, then copy the amd64 install files onto it and it would work). For OpenBSD 7.4 through 7.7 at least, this has not worked. I assume the i386 boot program is different from the amd64 boot program, and the amd64 kernels now expect something special that only the amd64 boot provides. In this sense, the reverse is untrue: if you cannot boot an amd64 bsd.rd, that does not necessarily mean you can't install it, just that booting that particular way doesn't work. So, I recommend in general that you make a fully amd64 installer USB drive. You could try putting i386 bsd.rd's on it but in my testing that works even less well than putting amd64 bsd.rd on an i386 USB drive. I just carry two OpenBSD USB drives in my pocket now, one for i386 and one for amd64. They are tiny. Also, EFI versus MBR can influence things and it seems like EFI systems prefer for you to use amd64 (e.g. a ThinkPad T480 will boot the amd64 bsd.rd from an amd64 USB key, but it won't boot the i386 bsd.rd from that same USB key and it won't boot anything from an i386 USB key). So really having the two separately is best. -ken
