mkarchiso: use -isohybrid-gpt-basdat instead of -appended_part_as_gpt for ISOs that will support BIOS booting

Some hardware, like Lenovo Thinkpad T420, will not BIOS boot if the disk has a valid GPT. See https://bbs.archlinux.org/viewtopic.php?id=264096 .

Instead of a valid GPT, change to a valid MBR and invalid GPT similar to what was used before 729d16b4. That layout, despite having crazy partition tables, boots everywhere.

The difference is that -append_partition is still kept and specified before -isohybrid-gpt-basdat. Thus the appended partition will be listed as EFI system partition in MBR and as Microsoft basic partition in the invalid GPT.

Fixes #102 (closed).

marked this merge request as ready

mentioned in issue #102 (closed)

Changes like these make me sad (irt how broken all of this is).

Thanks for looking into it and finding a fix! :)

merged

resolved all threads

mentioned in issue #63 (closed)

mentioned in issue #227 (closed)