[syslinux] Memdisk/XMS bug, big floppy image

[H. Peter Anvin]

Blaauw,Bernd B. wrote:
>>that image under B: or X: or whatever. This will allow us to cross the 
>>size limit of 2.88MB floppies. Ofcourse when I say "mount" I dont expect 
>>memdisk to mount it, just that set things up so that DOS mounts it there.
> 
> 
> I'm using a 5MB image which emulates floppydisk.
> 
> label test
>     kernel data/memdisk
>     append initrd=data2/test.img c=80 h=8 s=18 floppy
> 
> problems are I don't know how it was generated (Linux), how to insert bootsector.
> WinImage can edit the image (but not defragment it, or create it). 
> complete emulated harddisk images can't be opened by WinImage.
> 
> syslinux mailinglist:
> I may have found a Memdisk bug, but I'm not sure.
> Isolinux 2.08pre6, corresponding Memdisk file.
> DOS image, Freedos kernel 2032a-fat32
> 
> I'm trying first to get an answer from the freedos XMS driver maintainer.
> more info will be provided afterwards.
> 
> errors are these:
> 
> *case1:
> device=himem.exe / dos=high,noumb
> Kernel: allocated 40 Diskbuffers = 21280 Bytes in HMA
> 
> Invalid Opcode at 35A9 FFFF 0213 AA71 FFDC 0001 0E24 1095 0000 0001 0000 0002 0001
> 
> *case2:
> device=himem64.exe / dos=high,noumb
> Kernel: allocated 40 Diskbuffers = 21280 Bytes in HMA
> Invalid Opcode at 360F FFFF 0246 AA71 FFDC 0001 0E24 1095 0000 0001 0000 0002 0001
> 

As you can probably imagine, I have pretty much no way to debug this
particular problem based on the information above.  Hopefully the
FreeDOS people can better explain what needs to happen.

	-hpa