QEMU and GDB to debug bootsector

See Trying to use QEMU and GDB to debug GRUB 2

Start Qemu

• For Floppy:

  qemu -fda floppya.img  -s -S

• For CDROM:

  qemu -cdrom grub2.iso -s -S

Start GDB in another console

target remote localhost:1234
; as we start in 16bit real mode
set arch i8086
; set breakpoint in entry point, at begining of GRUB2's CD-ROM boot sector ode.
break *0x7c00
; entered 'c' to start execution until it hit the break point.


; to see where I really was I had to use following command:
x/10i $cs*16+$eip