Today I set up a ArchLinux install on a BIOS system using Syslinux.
The first partition (sda1, which contains
/boot) starts at 1049 kB. It has both
boot and
legacy_boot flags set. But I had to use
parted to set the
protective master boot record boot flag to "on" for the disk sda as well to have the BIOS to boot from that disk.
Does the
pmbr_boot flag always have to be set to "on" for a BIOS system to be able to boot from a GPT disk? Or are there some cases where it's enough that the boot partition itself has the boot flag set?