Subject: Re: port-i386/18591: biosboot bug: int13 func 0 needed after int13 func 2 error
To: None <>
From: David Laight <>
List: netbsd-bugs
Date: 10/09/2002 10:20:08
> It is actually a bug in the NetBSD bootloader which causes problems on
> CompactFlash cards with ID "Toshiba THNCF064MBA".
> The bootloader commands the BIOS to load sectors using Interrupt 0x13,
> function 2. According to "Ralf Brown's Interrupt List," when function 2
> indicates an error, you are supposed to call Interrupt 0x13, function
> 0, to reset the disk. The NetBSD bootloader does no such thing. LILO,
> which always works, does.

Is there any reason to suppose that this is change that makes
a difference to the problem being seen?

The boot loader shouldn't really see a disk read error, so the
error recovery path shouldn't be exercised.

When the boot fails, how far does it get.

(FWIW (and IIRC) there are some bugs in the asm boot code
that mean its operation is dependant on the BIOS having
cleared the top bits of some registers.  I certainly fixed
some longstanding bugs when hacking it a while ago.)


David Laight: