[syslinux] where to swap

Thomas Schmitt scdbackup at gmx.net
Mon Mar 27 00:52:44 PDT 2017


Hi,

> Building them [the isohdp*.bin MBRs]
> runs a check with checksize.pl that fails if they go beyond what's
> defined in checksize.pl.

I see. That's why your test MBRs and the two MBRs distributed by Debian
all have exactly 432 bytes.
So it would scream "too big" if we bonked against the limit.


> you should really clone the git
> repo and build it. It's not very hard.

My binary experiments are intentionally done with simple user means.
I want to collect debugging gestures to easily determine whether a
failure is about C/H/S addressing.


> Another good command is "objdump -D -b binary -m i8086 -M
> data16,addr16 isohdpfx.bin"

I am using meanwhile

  objdump -D -b binary -mi386 -Maddr16,data16 "$mbr" 2>&1 | less

(learned from stackexchange.com) to verify that my binary findings
match the disassembled form.
Further objdump ended my riddling about the effective length of
an instruction and its operands. Very educational.

But in the beginning of this adventure i really searched for
recognizable byte patterns in the binary. It's only 432 bytes.
(Many of them i know by name meanwhile.)


Have a nice day :)

Thomas



More information about the Syslinux mailing list