[OT] Freebios

[Tobias Diedrich]

I don't know if anyone here is interested in this, but some time ago (1998) I 
started writing a pc-compatible bios for fun, but never finished it.

So in case someone is interested in the little code I wrote you may find
it at http://ranmachan.dyndns.org/~ranma/freebios-0.0.1.tar.gz (~67KB) ...
[As long as my system is up, which should be nearly 24hours/day, and
my internet connection and the dyndns.org dns updates are working...]

I stopped because I had trouble figuring out how to enable SDRAM on my
Pentium Mobo with Intel chipset...
However for an older 486 Chipset there were specs in an old c't magazine, so
I was able to boot into dos with this piece of code...
(Don't know if it's still working, I did not try it recently...
The floppy code is buggy IIRC... No HD support)

Of course this probably doesn't help a bit with openbios development, but maybe
someone will find it interesting to look at :-)

GPL license, no reverse engineering of propriatary BIOSes was involved,
I had to go with only a few books (Basically "PC Hardwarebook" and 
"PC Programmers Guide to low level Functions and Interrupts")

[Ronald G Minnich]

On Wed, 29 Aug 2001, Tobias Diedrich wrote:
> I don't know if anyone here is interested in this, but some time ago (1998) I
> started writing a pc-compatible bios for fun, but never finished it.

that sounds neat! did you support BIOS style INT stuff? if you did we
could look at that.

ron

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[Tobias Diedrich]

Ronald G Minnich wrote:
> > I don't know if anyone here is interested in this, but some time ago (1998) I
> > started writing a pc-compatible bios for fun, but never finished it.
>
> that sounds neat! did you support BIOS style INT stuff? if you did we
> could look at that.

Yes it does.
That's the files in the SERVICE subdirectory...
SYSTEM.ASM (int 0x11, int 0x12, int 0x15)
FLOPPY.ASM (int 0x13)
KBD.ASM (int 0x16)
BOOT.ASM (int 0x19)
TIMER.ASM (int 0x1a)

However that's all 16bit code, I don't know how easy it would be to make
a F-Code BIOS be 16bit compatible... You probably would have to generate
16bit instructions from the F-Code...

[Stefan Reinauer]

* Tobias Diedrich  [010829 20:59]:
> Ronald G Minnich wrote:
> Yes it does.
> That's the files in the SERVICE subdirectory...
> SYSTEM.ASM (int 0x11, int 0x12, int 0x15)
> FLOPPY.ASM (int 0x13)
> KBD.ASM (int 0x16)
> BOOT.ASM (int 0x19)
> TIMER.ASM (int 0x1a)
>
> However that's all 16bit code, I don't know how easy it would be to make
> a F-Code BIOS be 16bit compatible... You probably would have to generate
> 16bit instructions from the F-Code...

To make it support initialization of graphics cards, for example, it would
only be necessary to support int10. SciTech's x86emu-0.7 does that for example.
older/other versions of this are used in the Alpha AXP Bootloader MILO
(http://www.suse.de/~stepan/) or in XFree86 (http://www.xfree86.org/)
There are different versions working with x86 emulation (for other platforms) 
or without for virtual x86 mode (ia32 compliant machines).
For other things like booting proprietary operating systems you might have to 
implement more, but it should be the goal, if at all, to keep the 16bit
compatibility code as small as possible. The API is ugly, circumstantial
and not up to date.

Best regards,
   Stefan Reinauer

[Edwin Rhodes]

Hi, thaks for sending me the code, which compiler do i use to recompile
it???
thanks
edwin

----- Original Message -----
From: "Tobias Diedrich" 
To: 
Sent: Wednesday, August 29, 2001 2:51 AM
Subject: [OpenBIOS] [OT] Freebios
> I don't know if anyone here is interested in this, but some time ago

(1998) I
> started writing a pc-compatible bios for fun, but never finished it.
>
> So in case someone is interested in the little code I wrote you may find
> it at http://ranmachan.dyndns.org/~ranma/freebios-0.0.1.tar.gz (~67KB) ...
> [As long as my system is up, which should be nearly 24hours/day, and
> my internet connection and the dyndns.org dns updates are working...]
>
> I stopped because I had trouble figuring out how to enable SDRAM on my
> Pentium Mobo with Intel chipset...
> However for an older 486 Chipset there were specs in an old c't magazine,

so
> I was able to boot into dos with this piece of code...
> (Don't know if it's still working, I did not try it recently...
> The floppy code is buggy IIRC... No HD support)
>
> Of course this probably doesn't help a bit with openbios development, but

maybe
> someone will find it interesting to look at :-)
>
> GPL license, no reverse engineering of propriatary BIOSes was involved,
> I had to go with only a few books (Basically "PC Hardwarebook" and
> "PC Programmers Guide to low level Functions and Interrupts")
>
> To unsubscribe: send mail to [e-mail]
> with 'unsubscribe openbios' in the body of the message

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[Tobias Diedrich]

Edwin Rhodes wrote:
> Hi, thaks for sending me the code, which compiler do i use to
> recompile it???

Borland Turbo Assembler ^^; Don't expect it to work though...  There are
two out instructions in the init.asm code that enable 4MB of mem on my
old 486 board, on any other chipset you have to code some memory
initialization first...

[Edwin Rhodes]

Well i had it booting in an old version of bochs, looks good.

----- Original Message ----- 
From: "Tobias Diedrich" 
To: 
Sent: Saturday, September 01, 2001 10:59 PM
Subject: [OpenBIOS] Re: [OT] Freebios
> Edwin Rhodes wrote:
> > Hi, thaks for sending me the code, which compiler do i use to
> > recompile it???
>
> Borland Turbo Assembler ^^; Don't expect it to work though...  There are
> two out instructions in the init.asm code that enable 4MB of mem on my
> old 486 board, on any other chipset you have to code some memory
> initialization first...
>
> To unsubscribe: send mail to [e-mail]
> with 'unsubscribe openbios' in the body of the message

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