Subject: Re: Booting a net4501 with a dumb CF card
To: <>
From: David Laight <>
List: current-users
Date: 07/25/2003 08:47:10
On Fri, Jul 25, 2003 at 06:20:46AM +0200, Quentin Garnier wrote:
> Hi,
> I've finally managed to boot my brand new net4501 box from the (poor) CF
> card I bought.
> First I had some geometry issues, but those were easy to solve.
> Then I was hit by the issue (often described in soekris-tech apparently)
> of the impossibility of reading more than one sector at a time through INT
> 13h on the CF card.

Send the CF card and/or BIOS back to the manufacturer.

CF cards do (at least the ones I've used did) support read commands
for more than one sector, so it is probably a BIOS bug.

The CF cards I used didn't support 'read multiple' (or rather they
reported a maximum sector count for it of one), but that has nothing
to do with the ability of the card to return more than one sector
in a single read operation - there are just separate data transfers
for each sector.  Indeed NetBSD probably does multi-sector reads.

IIRC there isn't much space in pbr.S - someone claimed it was 3 bytes
too big anyway - so some code would have to be removed in order to
fit the loop in.  The code that checks whether the BIOS supports
LBA reads is a prime candidate (the pbr code must have been read using
BIOS reads...)


David Laight: