On Wed, Sep 22, 2010 at 05:45:34PM +0200, Thomas Frauendorfer | Miray Software wrote: > On some boards, like the AsRock K7S41GX, Grub fails to boot from > superfloppy fat32 formated usb sticks. > > The reason for the boot failure is that the bios of the mentioned > board replaces byte 0x24 of the bpb with the value 0x00 when it's read > through the bios function. > In fat16 this byte contains the Disc unit number, so this causes no real > harm there. > In fat32 this byte is part of the sectors per FAT information, so by > modifying this value the bios makes Grub unable to read the fat system. > > The attached workaround reads the backup bpb information on fat32 > filesystems and uses the sectors per fat information stored there. > > PS: I'm sorry if this mail is a duplicate, but I sent it before but I > wasn't subscribed so it might have been blocked/dropped before
Wouldn't that be a bug in the BIOS? Don't go writing to a drive you don't know what contains. It could be something other tahn fat16 after all (what if it was a linux kernel with a bootheader on it and not a filesystem at all?) Sounds like the BIOS needs fixing badly. Nothing wrong with making grub more robust against corrupt filesystems, but it doesn't actually fix the bug in the BIOS. -- Len Sorensen _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org http://lists.gnu.org/mailman/listinfo/grub-devel
