[syslinux] memdisk and usb flash devices as primary hard drives.

[Quinn]

Has anybody tried to boot a dos disk via memdisk with a usb flash device 
as a primary hard drive?

I have a 512MB flash key that when connected becomes my primary hard 
drive (new bios) - 0x80.  If I boot a MS-DOS 7.10 floppy, one gets the 
command prompt and I can see the contents of my flash key as drive C:.

But, if I make a image of the floppy and boot the image via memdisk, 
then memdisk loads the floppy image to ram and tries to boot it but 
fails - the system just hangs after saying "Loading boot sector... 
booting...".

If you try to boot PC-DOS 7.0 via memdisk, then after seeing "Loading 
boot sector... booting...", PC-DOS reports "Starting PC-DOS..." and then 
hangs (but boots fine if booting from a physical floppy).

If I disconnect my flash key and boot again via memdisk, then booting is 
successful and I get a command prompt where I see my IDE disk as drive C:.

I have tested the problem both under pxelinux and under grub.  Syslinux 
seems to have problems installing itself onto the flash key - 
ldlinux.sys gets loaded onto the partition, I can see it modified the 
boot sector of the partition, the partition is also marked bootable 
(0x80),  but the mbr code just reports "Missing operating system" when I 
try to boot from the usb key.

Grub, on the other hand has no problems booting from the usb key (tried 
both version 0.93 and the latest cvs version).

Quinn