[syslinux] Using extlinux

H. Peter Anvin hpa at zytor.com
Thu Jan 20 08:13:05 PST 2005

Cullimore, Shaun (ACHE) wrote:
> Thanks for prompt reply.
>>>I am trying to boot Linux from a USB memory device containing an ext2
>>>file system using extlinux and having a bit of trouble. Apologies for
>>>any naiive questions and assumptions. The USB device is an 8M byte
>>>Compact Flash card in a USB reader.
>>Are you booting in USB-HDD or USB-ZIP mode?
> The machine I am using is a Hewlett-Packard and the BIOS is badged as
> HP.
> It only offers the option of booting from a "USB Device" (not "USB_FDD",
> "USB_ZIP", "USB_HDD", etc. as I have seen on others). I have since tried
> it
> on another machine with a Phoenix BIOS. This offers "USB HDD", "USB FDC"
> and "USB KEY". I would have thought that the first option would be
> correct
> but that and the second resulted in "Operating system not found". The
> "USB KEY" option appears to work but what formatting assumptions lies
> behind that?

"Operating system not found" means you didn't have the appropriate 
partition marked active in the partition table (in fact, it means you 
didn't have *any* partition marked active...)  Use the "a" command in 
fdisk to set this.

"USB KEY" is tricky; normally USB keys are treated exactly like 
harddrives, but since they have a separate option they are clearly 
applying some kind of heuristics.  It's entirely possible that if it 
sees you're using partition 4 that it assumes it's to be treated as a 
zipdrive, whereas if you're using partition 1 it assumes it's to be 
treated as a harddrive.  This is actually a fairly reasonable 
assumption.  If you want to try out that hypothesis, try creating disks 
which uses partition 1 and disks which uses partition 4.


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