28 Dec
2013
28 Dec
'13
8:08 p.m.
Mark,
On 2013-12-28 21:38, Mark Cave-Ayland wrote:
On 28/12/13 02:41, Philip Rhoades wrote:
Hmmm . . looks like I should be following tianocore on Sourceforge as
well . .
Thanks,
Phil.
--
Philip Rhoades
GPO Box 3411
Sydney NSW 2001
Australia
E-mail: phil(a)pricom.com.au
People,
I have been on this list for some time lurking - just because I think
it
is interesting that a bit of firmware can allow hardware to be
actually
useful! I haven't done more than read the occasional post that was of
interest but the thought occurred to me again about replacing the BIOS
that is on my current machine with something that is open so I went
back
to the OpenBIOS home page but was a bit puzzled to see on the Download
page: "Do not try to put OpenBIOS in a real boot ROM, it will not work
and may damage your hardware!". After a little more looking around I
am
still confused - the ultimate aim of this software is to eventually
allow people to replace their proprietary BIOSes right? I have an
Intel
MB DG45ID but I couldn't Google much overlap with OpenBIOS . .
Thanks for any enlightenment!
Regards,
Phil.
Hi Phil,
Basically there are two parts to the problem here: one is the
low-level hardware initialisation, while the second is adding the
required support for boot.
For low-level hardware initialisation, you'd need to use coreboot and
add OpenBIOS as an ELF payload - I did try this a few years back and
managed to get a Forth prompt working under QEMU. But there are some
things that OpenBIOS doesn't know, for example how much physical RAM
is in the machine which at the moment is obtained through a
QEMU-specific interface.
I suspect this is why the warning exists, as accessing these
QEMU-specific addresses will have undefined behaviour on real
hardware. So unless you can talk to coreboot then you'd need to
hardcode some specific defaults (which I believe is probably the
approach used by http://temlib.org to enable OpenBIOS to work on their
SPARC board).
Finally if you are using Intel hardware then you'll find that the
support is a lot weaker than other architectures (for example x86
OpenBIOS is currently real mode only, no PE support). My guess is that
this is because for more modern hardware, people are focusing their
efforts on developing open UEFI firmwares instead.