[syslinux] booting from usb

[Kent Robotti]

On Mon, Sep 12, 2005 at 10:17:52AM -0700, H. Peter Anvin wrote:
> Kent Robotti wrote:
> >
> >What would you tell extlinux to set the geometry for this flash drive?
> >
> >Disk /dev/sdb: 128 MB, 128974848 bytes
> >4 heads, 62 sectors/track, 1015 cylinders
> >Units = cylinders of 248 * 512 = 126976 bytes
> >
> >   Device Boot      Start         End      Blocks   Id  System
> >/dev/sdb1   *           1        1015      125829   83  Linux
> 
> If it has a partition table, it's not a floppy disk, and it doesn't need 
> geometry set.
> 
> A floppy disk doesn't have a partition table.  Instead you format the 
> root device (/dev/sdb in your case):
> 
> mke2fs /dev/sdb
> mount /dev/sdb /mnt
> extlinux -H 4 -S 62 /dev/sdb
> 
> ... assuming 4 heads, 62 sectors is the geometry you want.
> 
> Note that if fdisk gets the geometry right by default, extlinux should 
> be able to detect it automatically as well.

mke2fs -m0 -F /dev/sdb
mount /dev/sdb /mnt
extlinux /mnt             It just hangs!
extlinux -H 4 -S 62 /mnt  it hangs for a few seconds and displays "boot error"
extlinux -z /mnt          It works and displays "CBIOS" etc.

Can extlinux be installed on a mounted ext2 partition and work, or
must it be the whole device?

Because, if i do this it doesn't work, but that may be because of the
limitations of my BIOS.

mke2fs -m0 /dev/sdb1  "There's one active Linux partition on the drive!"
mount /dev/sdb1 /mnt
cat mbr.bin >/dev/sdb
extlinux /mnt or extlinux -H 4 -S 62 /mnt or extlinux -z /mnt

My BIOS dosen't even recognize the drive.