Re: ISO installer image: GPT versus MBR partitions

[Thomas Schmitt]

Hi,

Ludovic Courtès wrote:
> > I lost track of the discussion.  You’re looking at a MacBook-specific
> > issue, right?

Florian Pelz wrote:
> As I understand it, Thomas’ work is about
> - making a correct ISO image and

The grub-mkrescue ISOs are correct but also sometimes inconvenient on
USB stick. So rather:
- Making ISO images which are more digestible for partition interpreters
  when presented unchanged on real storage devices. Especially for
  partition editors by which the user wants to add a read-write data
  partition to the USB stick.

> - making it work on more machines.

In this case it's about the Macbook EFI and mformat's partition table
entry. Exotic but also typical for firmware quirks.

----------------------------------------------------------------------

In general my proposal is about getting control over the GRUB-produced
files before xorriso packs them up, and over the arguments of the xorriso
run.

Danny pointed out that Guix ISO production software does not aim for
becomming expert for iso bootloaders.
But the Macbook EFI behavior and the Linux partition table complaints
do not demand deep knowledge of bootloaders. The remedies just need the
opportunity to make small adjustments to the work of grub-mkrescue.

Where such remedies come from, is a different question.
Count on frustration-tolerant users and curious bystanders.

The shell script implementation is somewhat questionable. We could use
it for exploring the best variation and then implement that variation
in a less tolerant programming language with less outer influences.

I asked Danny, whether the download servers could offer two partition
table variations of the ISOs: GPT and MBR (both with APM/HFS+).
Goal would be to gain experience with MBR and to finally replace GPT
by that layout.
He expressed the hope that other members of Guix could answer this.


Have a nice day :)

Thomas