[syslinux] makebootfat: an utility to create bootable USB disks

[H. Peter Anvin]

Andrea Mazzoleni wrote:
> On Tue, 22 Feb 2005 14:30:24 -0800, H. Peter Anvin <hpa at zytor.com> wrote:
> 
>>Very useful!  Just as a small warning, USB-FDD *may* not work for you,
>>depending on exactly which quirks the BIOS assumes for it.
> 
> Do you have more details on these quirks ? I've access at only two
> USB-FDD BIOS, and in both of them this format is working.
> 
> The only difference than a standard FDD format is only the unusual
> value of the number of "hidden"  sectors after the FAT boot sector.
> Maybe this can confuse some BIOS.
> 
> Anyway, on my understanding this is the most compatible format. 

What I meant is the annoying fact that there isn't an easy way to query 
the geometry the BIOS is using for a floppy disk; there is a query call 
but it returns the "capabilities of the device", not the actual one in use.

USB-FDD may very well assume a floppy-sized device, and could at least 
theoretically be limited to 1.44 MB.

Both USB-ZIP and USB-FDD use some kind of hardwired geometry, and there 
are apparently some "USB-ZIP" variants that simply ignore the first 32 
sectors and present the device as a large floppy drive.

Barf.  USB-HDD is so clearly the only sane mode for stick drives.  Too 
bad it doesn't seem to work everywhere, including on at least one system 
I have.

	-hpa