On 6/7/21, Rao G wrote:
> Please look into this document too about Disk On Chip
> https://www.coreboot.org/images/9/97/LinuxBIOS.pdf
>
I'll check it out yet.
>> Branden wrote...
>>
>> In the first place, I think my assumption of it exposing a large rom
>> was wrong, it looks like they only actually only expose a small amount
>> as regular bios boot rom space. While that sounds annoying, it would
>> probably still be workable though.
>>
>>…
>>
>>I'm hoping that somebody still remembers a bit about them and maybe
>>knows something about how I can get the chip working, confirm that
>>it's not working, or just tell me I'm doing it wrong.
>
> Andy wrote...
>
> It has been a long time since I have used one of these (and never with
> coreboot) but from what I > remember the device needed something like 16KB in
> the expansion ROM area (between 640KB > and 1MB).
>
> The DiskOnChip contained firmware that was executed as a BIOS extension /
> option ROM. For > DOS based systems the firmware hooked onto int 13h (disk
> services) so that it got allocated a > drive letter and also handled the the
> flash paging / erasing / reading / writing. I used devices> with
> capacities ranging from 2MB to 256MB and they all only needed the same amount
> of space > in the ROM area.
> My first question… what have you plugged the DiskOnChip into? Is it a
> motherboard that was > designed to accept them or is it a plug in card with
> a ROM socket on it? (M-Systems initial> evaluation board was an ISA
> card).
I tried it in both my p2b and a sis 630 board. I don't have an
evaluation board and though I have some pci and isa cards with dip32
sockets, I'm not sure that they would load an option rom properly or
even be (io) compatible.
I don't even know if the option rom firmware would be on the chip,
because it looks like it is programmable and it could have been wiped
or had an incompatible version.
Obviously the option rom is not going to be loaded/ do anything when
hotswapping though.
> Peter wrote:
> On hardware level the device exposes only a window of its full capacity
> at a time. The electrical interface which it plugs into only has a
> limited address space. Software must have not only a driver for the
> device which knows how to move the window around but also an
> abstraction layer for memory access so that the driver can move the
> window at the correct time.
>
> This is not in place for current coreboot boards.
I figured it operated something like that, though I didn't really
think of that before I got it.
If it worked, had enough space in the boot block for a functioning
rom/bios, and could load the option rom it in theory should still be
usable in some form though.
>> Going by the "HOWTO" documentation in the coreboot_v1 branch I figured
>> I could just hotswap it and load the diskonchip kernel module,
>
> Good thinking, I believe this ought to work as long as the driver
> supports your device.
Well, I couldn't really find much information about if mainline linux
_ever_ even properly supported the diskonchip 2000. Some of what I
found referred to 2.4, which I'm definitely not messing with unless I
absolutely have to. If I could find proper info on a 2.6 or later
kernel supporting it natively it probably wouldn't be to hard to test,
though I'd likely still need to use an old distro image.
>> but I can't find any information about whether that actually supports
>> the diskonchip 2000 or has been tested recently.
>
> Also good thinking - please be aware that DiskOnChip and DiskOnChip 2000
> are different products which are *not* compatible.
Yeah, search engines don't seem to realize there is a difference
either, which was pretty annoying.
Well the DiskOnChip 2000 at least sort of makes sense (as a main
firmware boot rom), none of the rest of their products seem to. Using
an adapter card for "proprietary" nand storage doesn't make sense and
branded cf cards don't really offer an advantage over any other cf
card supplier - though it is possible they had better controllers, I
have my doubts.
Now a days, even though I've seen lots of recommendations for ide to
cf adapter and cf card usage for retro computing, I found a pci to
sata adapter to work fine and not have the issue of expensive cf cards
with unknown controller quality. Obviously that wouldn't work for
pre-pci systems, but I don't think any of those are supported by
coreboot anyways :).
>> I tried the dos utils on freedos as well and couldn't get them to
>> detect it either.
>
> If that doesn't work, nothing else will.
Well, that's what I was afraid of.
I only managed to find working links for the dos utils (and much of
the other software) from here:
http://www.digital-circuitry.com/MyLAB_IC_PROG_DISKONCHIP.htm
I tried V4.20 and V5.14 of the ms-dos software utilities, but couldn't
detect it.
The chip I have is branded "Ver. 5.1.2", but I'm not sure how much that matters.
>> I'm hoping that somebody
