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

Martin Str|mberg
Sun, 19 Mar 2017 12:21:30 -0000

Thomas Schmitt wrote:
> I ponder whether it would be possible to create a diagnostic MBR
> which does not necessarily have to boot but rather tells what the
> isohybrid MBR would perceive: Presence of partition table,
> EBIOS or CBIOS, block address used with INT 13, content of the block
> read by the first INT 13, ...
...
> The diagnostic MBR should only use 432 bytes because at byte 432
> to 435 of the isohybrid MBR there is the 512-byte-block address of
> file isolinux.bin, which was patched in by isohybrid or xorriso.

Yes. What exactly should be printed? Perhaps we'd need several
diagnostic ones if the space is too small.
Or possibly in two parts, if there are four bytes that must be
preserved in the middle, but that might be messy.

Like:
P
or
N for partition table or not. How is the presence of partition table
detected?

And
E
or
C
for EBIOS or CBIOS.

Exactly what block address are you talking about? Do you mean the LBA
(/CHS) address?

The content of a block? Like a hex dump of 512 bytes?
Like ABDEFABDEBDA872342ABD2323784...?


--
MartinS