Re: UEFI PC?
Hi,
Samuel Thibault wrote:
> Actually there is no technical reason why it shouldn't work: it's grub
> which has to care about BIOS vs UEFI.
>
> That being said, it seems that the hurd-i386 variant of the Debian
> installation CDs can't be booted on UEFI. I don't know why, it's using
> grub, like the i386 variant.
The immediate cause is the lack of an El Torito boot image for UEFI and of
an EFI System Partition.
(Looking at debian-sid-hurd-i386-NETINST-1.iso, 2017 06 20 12 43 44 00.)
On an amd64 system i can get UEFI equipment in a grub-mkrescue ISO
by installing binary packages grub-efi-amd64-bin and/or grub-efi-ia32-bin.
This can be further combined with grub-pc-bin for PC-BIOS.
Then i run grub-mkrescue with a dummy payload directory instead of a
directory tree with operating system files:
mkdir minimal
grub-mkrescue -o output.iso minimal
The result should then have EFI System Partition and El Torito image in
personal union, containing start programs for i386 and/or amd64.
Further there should be bootable MBR code and El Torito image for PC-BIOS.
Partition table is GPT. Have a look at Guix ISOs which get built by
grub-mkrescue. (There is also HFS+/APM stuff for antique x86 Macs.)
The Volume Id of the Hurd ISO from june 2017 looks like debian-cd
Volume Id : Debian sid h-i386 n
But it has GRUB equipment for PC-BIOS rather than the usual ISOLINUX.
Well, debian-cd is flexible.
If it's that what you are using, let's talk to Steve McIntyre when he is
done with converting Jigdo to SHA256.
Whatever, it will be not a big obstacle to develop a xorriso run if
you have all GRUB equipment ready for EFI. It may also be a good
opportunity to switch to grub-mkrescue for ISO generation (and my wrapper
script for making MBR partitions rather than GPT).
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I cannot say whether there is nothing which the Mach kernel would want from
the firmware. Maybe ask Steve McIntyre whether he had to wait for special
Linux precautions before being able to boot amd64 via EFI (long ago).
Have a nice day :)
Thomas
Running with C source
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