What's "probe_values: .byte 36, 18, 15, 9, 0" on MBR(stage1.S) of grub legacy(0.97)

saeedsssss · 12-29-2012, 03:03 PM

I read stage1.S of grub legacy
and see this code
#====================
probe_values:
.byte 36, 18, 15, 9, 0
#===================
from line 449
(place of stage1.S on source code is "grub-0.97\stage1\stage1.S " )
what do that do?
What's meaning of that?

for example ,what's 36 and other numbers

Habitual · 12-30-2012, 12:05 PM

I googled ".byte 36, 18, 15, 9, 0" and found a hit that seem to point resetting the FDC, or Floppy Disk Controller.

3.8. Miscellaneous says

Code:

///////////////////////////////////////////////////////////////////////////////
// some small functions
print_all();  /* print error code, AX, BX, CX and DX */
print_nl();   /* print CR LF */
print_hex();  /* print the word pointed to by SS:BP in hexadecimal */
kill_motor()  /* turn off floppy drive motor */
{
#if 1
        int13/AH=00h(DL=0);     // reset FDC
#else
        outb(0, 0x3F2);         // outb(val, port)
#endif
}

///////////////////////////////////////////////////////////////////////////////
sectors:        .word 0
disksizes:      .byte 36, 18, 15, 9
msg1:           .byte 13, 10
                .ascii "Loading"

But I am not sure. Just a guess.