Re: ISO installer image: GPT versus MBR partitions

["pelzflorian (Florian Pelz)" <pelzflorian@pelzflorian.de>]

On Wed, Apr 24, 2019 at 11:13:23AM +0200, pelzflorian (Florian Pelz) wrote:
> On Wed, Apr 24, 2019 at 08:56:57AM +0200, Thomas Schmitt wrote:
> > Florian Pelz wrote
> > > By the way, someone I know has a most peculiar machine called Lenovo
> > > Ideapad 100S which does not boot Guix, […]
> > 
> > If Guix does not show up in the boot manager, try a plain grub-mkrescue
> > image that was made when GRUB was configured for both EFI variations:
> > 32 bit x86 and 64 x86.
> > My experiments are made when it is configured for those two plus PC-BIOS.
> > The EFI partition then has bootx64.efi and bootia32.efi in /efi/boot/.
> > 
> 
> Will do.
> 

The Lenovo Ideapad 100S’s owner tried a USB drive prepared with a
purely 32-bit GRUB as per

On Thu, Apr 25, 2019 at 10:18:08AM +0200, Thomas Schmitt wrote:
>   wget https://dev.lovelyhq.com/libburnia/libisoburn/raw/master/frontend/grub-mkrescue-sed.sh
>   chmod u+x grub-mkrescue-sed.sh
> 
>   export MKRESCUE_SED_MODE=mbr_hfs
>   export MKRESCUE_SED_IN_EFI_NO_PT=yes
> 
>   grub-mkrescue --xorriso=./grub-mkrescue-sed.sh  \
>                 -iso_mbr_part_type 0x83 -partition_offset 16 \

-o mbrhfs.iso

and it boots fine.

I do not know and did not try yet how to configure GRUB to produce
both 32-bit and 64-bit EFI.  (Would putting both 32-bit and 64-bit
bootefi files in EFI/Boot/ be a good idea for Guix ISOs in general, or
could this lead to problems with 64-bit machines or lead to confusing
boot selection screens?)

A Debian 9.8.0 32-bit also boots fine and a DVD with an untreated Guix
git master could not be booted but very likely due to an error with my
external DVD drive (it often does not work) and not due to an error
with the DVD.

I will try a current git master Guix iso built for 32-bit next.  If it
does not work (guixsd-install-0.15.0.i686-linux.iso did not work), I
will try the same with

dd if=/dev/zero bs=1 count=16 seek=446 of=/dev/sdc2

Regards,
Florian