[syslinux] Possible memdisk issue

[Ady]

> On 07/09/2014 04:00 PM, H. Peter Anvin wrote:
> >
> > So this would seem consistent that this is the FAT12/FAT16 boundary that
> > breaks stuff.  Perhaps FreeDOS has a problem with FAT16 on floppies?
> 
> If I understand things correctly, a bootable floppy has two key pieces 
> of executable code: the 512-byte boot sector, and the kernel loaded by 
> that boot sector.
> 
> The kernel can be large, and thus could perhaps in principle auto-detect 
> FAT12, FAT16, FAT32, whereas the boot sector code is limited to around 
> 460 bytes (as file system config data is also stored in there), so 
> perhaps that's not enough space for auto-detection code? Perhaps there 
> simply have to be 3 different boot sectors, depending on whether you've 
> got FAT12, FAT16, or FAT32? That would explain what's happening here: 
> newmkfloppyimg called mkdosfs, who made a different file system, yet 
> newmkfloppyimg copied over the old file system's boot sector...
> 
> Does anyone know whether it is possible to have a "universal" boot 
> sector and "universal" kernel? Then if one starts with a base floppy 
> image containing those, then newmkfloppyimg should create something 
> bootable no matter what size is specified.
> 
> Alex
 
We might be getting off-topic.

Is there a FAT{12,16} superfloppy image that MEMDISK is currently 
unable to boot?

When building a FAT image, containing the _latest_ FreeDOS kernel, by 
using the _latest_ mtools (and/or _latest_ dosfstools), can MEMDISK 
load it correctly?

I wouldn't be so surprised to have some kind of problem with an image 
built by an old version of mtools / dosfstools containing an old 
FreeDOS kernel.

As I mentioned before, I have used MEMDISK with bigger floppy images. 
If there is a specific set of FAT parameters that triggers a problem 
for MEMDISK, I would like to hear about them.

Regards,
Ady.