Comment 38 for bug 277903

On Sun, 2009-04-26 at 10:53 +0000, Anders Häggström wrote:
> The output from the diagnostic MBR (the link from TJ on 2009-03-30) when
> I hold CTRL-key own during boot is: "L D80 C07C HFF S3F P1 O0000003F
> MAA55 E00". I have no clue of what that means but I hope it is valuble
> for TJ. :)

Here's the documentation from my mbr-diag.S source submitted to syslinux upstream:

 Due to the severe space constraints the output uses 1-character description codes to prefix each printed value.
 Values are in hexadecimal.

 Description Codes:
 L | C LBA or CHS addressing mode
 D drive number BIOS-reported drive number
 C cylinders Geometry of drive according to BIOS
 H heads
 S sectors
 P partition active partition number (first partition flagged active). '?' if no active partition
 O offset absolute sector offset of active partition . '????????' if no active partition
 M magic magic bytes of active partition boot sector (sector <offset> as read by BIOS).
      '????' if no active partition. Value is reset to 0xDEAD before the sector is read
      to avoid inheriting the MBR magic on error
 E error error code returned by BIOS 'read sector' interrupt (0x02 or 0x42, int 0x13).
      '??' if no active partition.