[syslinux] memdisk and floppy images on 4801

[Jim Cromie]

Im trying to boot memtest86 via pxelinux, memdisk,
I found this advice on http://forum.x86-secret.com/viewtopic.php?t=2906

folks are making the image match a floppy size by one of the following:

dd if=memtest86+-1.xx.bin of=memtest.img bs=360k count=1 conv=sync
or
dd bs=360k count=1 conv=sync if=memtest86+-1.xx.bin|gzip > memtest.gz

I did the former, it did suppress the warning/errors I saw previously,
...
MEMDISK: Image has fractional end sector
MEMDISK: Image seems to have fractional end cylinder
MEMDISK: Image appears to be truncated
Disk is floppy, 92 K, C/H/S = 80/2/18

but it doesnt work, it hangs after this:

Loading memdisk....
Loading memtest.img........
Ready.
MEMDISK 3.08 2005-05-19  Copyright 2001-2005 H. Peter Anvin
e820: 0000000000000000 000000000009fc00 1
e820: 000000000009fc00 0000000000000400 2
e820: 00000000000f0000 0000000000010000 2
e820: 0000000000100000 0000000007f00000 1
e820: 00000000fff00000 0000000000100000 2
Ramdisk at 0x07f86000, length 0x0005a000
command line: initrd=memtest.img BOOT_IMAGE=memdisk memtest.img
Disk is floppy, 360 K, C/H/S = 40/2/9
Total size needed = 1898 bytes, allocating 2K
Old dos memory at 0x9f800 (map says 0x9fc00), loading at 0x9f000
1588: 0xffff  15E801: 0x3c00 0x06f8
INT 13 08: Failure, assuming this is the only driveold: int13 = 
f00023c0  int15 = f000509e
new: int13 = 9f000008  int15 = 9f000286
Loading boot sector... booting...



in memtest.doc, you say

b) If the disk image is one of the following sizes, it's assumed to be a
   floppy image:

     368,640 bytes -  360K floppy
...
   For any other size, the image is assumed to be a hard disk image,
...
   floppy       The image is a floppy image
   harddisk     The image is a hard disk image



This suggests that appending floppy should tell memdisk how to handle 
odd sized
images, which is not the case.  Is this a doc, code, or a PEBCAD
(problem exists between chair and Display) issue ?


does the INT 13 failure look similar to any of the bugs you suspect are 
in the soekris bios ?
Im referring to "boot Soekris 4801 with EXTLINUX";  Im doing this 
testing on my soekris 4801.

FWIW, someone posted to soekris ML recently, saying that the bios looks 
like a derivative
of PCengines tinybios.  Have you encountered this bios before ?