[syslinux] simple message under BIOS/CSM/LEGACY

[Gregory Bartholomew]

On Wed, Aug 3, 2022 at 11:57 AM Pascal via Syslinux <syslinux at syslinux.org>
wrote:

>
> the only point that seems contentious to me is whether a partition can have
> its first sector set to zero ?
>

It depends on the file system, not the partition. Most file systems avoid
placing any data specifically to avoid overwriting a MBR or PBR. The offset
to avoid writing to is even configurable on some file systems (e.g. FAT).


> does the BIOS check this kind of thing ?
>

Ideally the BIOS wouldn't care at all about partitions or file systems and
it would just load and execute the first bytes from the disk.
Unfortunately, that isn't always the case. Trivia: the linux kernel used to
have a header that made it possible to "dd" it directly to a floppy disk
and old BIOS systems would boot it -- no file systems, no partitions, the
BIOS would just init the hardware and then directly load the linux kernel.