From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <a77c4323250515950a91c39ef7a93913@plan9.bell-labs.com>
Date: Wed,  4 Oct 2006 22:59:33 -0400
From: jmk@plan9.bell-labs.com
To: 9fans@cse.psu.edu
Subject: Re: [9fans] CF boot failure
In-Reply-To: <32859583614e4e3c2f88c14976531cb8@quanstro.net>
MIME-Version: 1.0
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
Topicbox-Message-UUID: c52e0672-ead1-11e9-9d60-3106f5b1d025

from what i remember, 'removeable ide' doesn't always mean
'hard disc', sometimes it means 'floppy'. a cd is a 'removeable ide',
as is an atapi zip drive. in the case of the zip, it can be
treated by the bios as either a hard disc or a floppy and which it
is determines what goes in the first sector and what the arguments
to the bios disc read calls are. it's a crap-shoot, each manufacturer
deals with them in a different way.

i/o error comes directly from attempting to read a sector.
it's possible the info in the mbr partition table doesn't match
the hardware disc configuration (e.g. the address of the pbs)
but the only thing the mbr has to do is
	check there is a good active partition table entry
		if this fails you get a different error message
	read the single first sector of the active partition
		if this fails you get 'i/o error'
	check the signature at the endo of the read sector
		if this fails youj get a different error message
	jump to the start of the read sector
so the bios is not letting you read the first sector of
the active partition. why, i don't know. can you boot anything
off this cf card?

On Wed Oct  4 22:27:32 EDT 2006, quanstro@quanstro.net wrote:
> the bios recognizes it as as "removable ide".  here's what the phoenix bios says about the
> situation
> 
> type	 auto
> 	chs
> c	2025
> h	16
> s	63
> cap.	1045 MB
> 	lba format
> 
> multi-sector transfers	disabled
> lba mode control		disabled
> 32-bit i/o			enabled (i've also tried disabled)
> transfer mode		fast pio4
> udma mode		disabled