[syslinux] Bug#857597: "isolinux.bin missing or corrupt" when booting USB flash drive in old PC

[Thomas Schmitt]

Hi,

David Christensen wrote:
> http://cdimage.debian.org/debian-cd/current/i386/iso-cd/debian-8.7.1-i386-xfce-CD-1.iso

Background info:

This is an isohybrid made by xorriso, equivalent to a run of
  isohybrid --uefi

There is a probably useless Apple Partition Map pointing to the UEFI
System Partition. The whole UEFI aspect is to be ignored by a BIOS
from 2003, i suppose.

The block address pointer from MBR to isolinux.bin looks ok.
Confirmed by xorriso analysis and by newer BIOSes which boot.


>     isolinux.bin missing or corrupt

Somehow the MBR code, when run on the old BIOS, seems not to like
isolinux.bin and thus refuses to hop on it.

If i get
  http://git.zytor.com/syslinux/syslinux.git/tree/mbr/isohdpfx.S#n201
right, then the error message is emitted if reading succeeds but does
not yield the expected values in bytes 64 to 67, which serve as magic
number to identify an isohybrid-ready El Torito boot image.

(I could need a reference document for the assembler language in isohdpfx.S.
 Does anybody know a good one ?)


Have a nice day :)

Thomas