[LinuxBIOS] ADLO & biosdecode

[Jun Koi]

Hello,

I am running LinuxBios + ADLO with QEMU. Strangely, biosdecode now
outputs nothing.

If I use the original QEMU BIOS, at least biosdecode reports BIOS32
Service Dir + PCI IRQ table + ACPI.

So why LinuxBIOS removes those information?

Many thanks,
Jun

[Peter Stuge]

Hello Jun,

On Wed, Dec 05, 2007 at 12:54:42PM +0900, Jun Koi wrote:
> If I use the original QEMU BIOS, at least biosdecode reports BIOS32
> Service Dir + PCI IRQ table + ACPI.
>
> So why LinuxBIOS removes those information?

This is on purpose.

One motivation for LB is that most if not all interfaces that are
associated with the term BIOS should be deprecated.

LB does not strive to be BIOS compatible by design.

Instead of offering callbacks, LB wants a linear program flow during
boot, where initialization hands over to a payload, which hands over
to the operating system, which then, in fact, operates the system.

This is a slightly new concept also for operating systems, since they
are used to relying on the BIOS at least for some things, but we are
making (admittedly pretty slow so far) progress.

//Peter

[Stefan Reinauer]

Peter Stuge wrote:
> Hello Jun,
>
> On Wed, Dec 05, 2007 at 12:54:42PM +0900, Jun Koi wrote:
> > If I use the original QEMU BIOS, at least biosdecode reports BIOS32
> > Service Dir + PCI IRQ table + ACPI.
> >
> > So why LinuxBIOS removes those information?
>
> This is on purpose.
>
> One motivation for LB is that most if not all interfaces that are
> associated with the term BIOS should be deprecated.
>
> LB does not strive to be BIOS compatible by design.

But this is not true for Jun's setting with LinuxBIOS + ADLO.

I don't think we remove anything on purpose there.

Jun, maybe you are using the 64k Qemu BIOS instead of the 128K version?
In that case you won't see BIOS32 services.

[Jun Koi]

On 12/5/07, Stefan Reinauer  wrote:
> Peter Stuge wrote:
> > Hello Jun,
> >
> > On Wed, Dec 05, 2007 at 12:54:42PM +0900, Jun Koi wrote:
> > > If I use the original QEMU BIOS, at least biosdecode reports BIOS32
> > > Service Dir + PCI IRQ table + ACPI.
> > >
> > > So why LinuxBIOS removes those information?
> >
> > This is on purpose.
> >
> > One motivation for LB is that most if not all interfaces that are
> > associated with the term BIOS should be deprecated.
> >
> > LB does not strive to be BIOS compatible by design.
>
> But this is not true for Jun's setting with LinuxBIOS + ADLO.
>
> I don't think we remove anything on purpose there.
>
> Jun, maybe you are using the 64k Qemu BIOS instead of the 128K version?
> In that case you won't see BIOS32 services.

Hmmm... indeed! My bios.bin size is 64KB. I am using the bios coming
with ADLO (bochs/bios/ in ADLO directory)

So I understand that the 64KB bios only provides 16bit BIOS, and the
128KB (which is catted by 16bit (64K) + 32bit (another 64K)) provides
both 16bit & 32bit BIOS?

If that is correct, how to get the 128K BIOS now?

Thanks,
Jun

[Jun Koi]

On 12/5/07, Stefan Reinauer  wrote:
> Peter Stuge wrote:
> > Hello Jun,
> >
> > On Wed, Dec 05, 2007 at 12:54:42PM +0900, Jun Koi wrote:
> > > If I use the original QEMU BIOS, at least biosdecode reports BIOS32
> > > Service Dir + PCI IRQ table + ACPI.
> > >
> > > So why LinuxBIOS removes those information?
> >
> > This is on purpose.
> >
> > One motivation for LB is that most if not all interfaces that are
> > associated with the term BIOS should be deprecated.
> >
> > LB does not strive to be BIOS compatible by design.
>
> But this is not true for Jun's setting with LinuxBIOS + ADLO.
>
> I don't think we remove anything on purpose there.

Yes, I guess the information (biosdecode) must be there, as I use Boch
BIOS with LinuxBIOS, but not LinuxBIOS only.

And interestingly, there is no option to make 32bit BIOS in
ADLO/bochs/bios/Makefile. I simply generated bochs/bios/bios.bin by
running "make" inside ADLO/

So I think the question becomes: how to get 32bit BIOS now?

Thanks,
Jun

[Myles Watson]

> -----Original Message-----
> From: [e-mail] [mailto:linuxbios-
> [e-mail]] On Behalf Of Jun Koi
> On 12/5/07, Stefan Reinauer  wrote:
> > Peter Stuge wrote:
> > > Hello Jun,
> > >
> > > On Wed, Dec 05, 2007 at 12:54:42PM +0900, Jun Koi wrote:
> > > > If I use the original QEMU BIOS, at least biosdecode reports BIOS32
> > > > Service Dir + PCI IRQ table + ACPI.
> > > >
> > > > So why LinuxBIOS removes those information?
> > >
> > > This is on purpose.
> > >
> > > One motivation for LB is that most if not all interfaces that are
> > > associated with the term BIOS should be deprecated.
> > >
> > > LB does not strive to be BIOS compatible by design.
> >
> > But this is not true for Jun's setting with LinuxBIOS + ADLO.
> >
> > I don't think we remove anything on purpose there.
>
> Yes, I guess the information (biosdecode) must be there, as I use Boch
> BIOS with LinuxBIOS, but not LinuxBIOS only.
>
> And interestingly, there is no option to make 32bit BIOS in
> ADLO/bochs/bios/Makefile. I simply generated bochs/bios/bios.bin by
> running "make" inside ADLO/
>
> So I think the question becomes: how to get 32bit BIOS now?

You need to add a new version of the loader since the BIOS is larger, and
use the larger elf header.

I'm planning on doing that in the near future.

Myles

[Jun Koi]

On 12/5/07, Myles Watson  wrote:
> > -----Original Message-----
> > From: [e-mail] [mailto:linuxbios-
> > [e-mail]] On Behalf Of Jun Koi
> > On 12/5/07, Stefan Reinauer  wrote:
> > > Peter Stuge wrote:
> > > > Hello Jun,
> > > >
> > > > On Wed, Dec 05, 2007 at 12:54:42PM +0900, Jun Koi wrote:
> > > > > If I use the original QEMU BIOS, at least biosdecode reports BIOS32
> > > > > Service Dir + PCI IRQ table + ACPI.
> > > > >
> > > > > So why LinuxBIOS removes those information?
> > > >
> > > > This is on purpose.
> > > >
> > > > One motivation for LB is that most if not all interfaces that are
> > > > associated with the term BIOS should be deprecated.
> > > >
> > > > LB does not strive to be BIOS compatible by design.
> > >
> > > But this is not true for Jun's setting with LinuxBIOS + ADLO.
> > >
> > > I don't think we remove anything on purpose there.
> >
> > Yes, I guess the information (biosdecode) must be there, as I use Boch
> > BIOS with LinuxBIOS, but not LinuxBIOS only.
> >
> > And interestingly, there is no option to make 32bit BIOS in
> > ADLO/bochs/bios/Makefile. I simply generated bochs/bios/bios.bin by
> > running "make" inside ADLO/
> >
> > So I think the question becomes: how to get 32bit BIOS now?
>
> You need to add a new version of the loader since the BIOS is larger, and
> use the larger elf header.

You mean the new version of ADLO is needed?
> I'm planning on doing that in the near future.

Anything I can help here? Or if you can give some hints, I will try to
do something (Currently I am not used to the ADLO code yet)

Thanks,
Jun

[Myles Watson]

> > You need to add a new version of the loader since the BIOS is larger,
>
> and
> > use the larger elf header.
>
> You mean the new version of ADLO is needed?

Yes,

The file loader.s copies the BIOS into RAM and sets up the CMOS values.  If
you use the 32-bit BIOS, you need to make sure all of it gets copied.  I was
also messing around with this because the loader needs to be 4k-aligned to
work with kexec, and that's the pathway I want to use.
> > I'm planning on doing that in the near future.
>
> Anything I can help here? Or if you can give some hints, I will try to
> do something (Currently I am not used to the ADLO code yet)

These emails are from my latest progress.  I hope to get back to it soon,
but I'd love it if you beat me to it.

http://www.mail-archive.com/[e-mail]/msg12748.html
http://www.mail-archive.com/[e-mail]/msg12724.html

Feel free to ask specific questions once you're digging.

Thanks,
Myles
> Thanks,
> Jun

[Corey Osgood]

Jun Koi wrote:
> Hello,
>
> I am running LinuxBios + ADLO with QEMU. Strangely, biosdecode now
> outputs nothing.
>
> If I use the original QEMU BIOS, at least biosdecode reports BIOS32
> Service Dir + PCI IRQ table + ACPI.
>
> So why LinuxBIOS removes those information?

They simply aren't necessary for QEMU ;) LinuxBIOS doesn't provide BIOS
callbacks, hence no BIOS32. There's a PIRQ table in the QEMU directory,
but since there are no "real" interrupts, it's not needed, and isn't
built by default. And there's no need for power management in a virtual
machine, so that's not provided either. PIRQ tables and ACPI are
supported by LinuxBIOS, but which of these are included/used depends on
the person who writes the port.

-Corey

[Jun Koi]

On 12/5/07, Corey Osgood  wrote:
> Jun Koi wrote:
> > Hello,
> >
> > I am running LinuxBios + ADLO with QEMU. Strangely, biosdecode now
> > outputs nothing.
> >
> > If I use the original QEMU BIOS, at least biosdecode reports BIOS32
> > Service Dir + PCI IRQ table + ACPI.
> >
> > So why LinuxBIOS removes those information?
>
> They simply aren't necessary for QEMU ;) LinuxBIOS doesn't provide BIOS
> callbacks, hence no BIOS32. There's a PIRQ table in the QEMU directory,
> but since there are no "real" interrupts, it's not needed, and isn't
> built by default. And there's no need for power management in a virtual
> machine, so that's not provided either.

This is not always true. I heard about of some projects (Xen related)
which try to do some power management for VMs (so for example they can
slow down when the system is on battery). And to do that, the VMs must
be aware of the power status of the (physical) system.

Thank you,
Jun