[Qemu-devel] booting linux 2.6 in qemu-system-ppc

[Qemu-devel] booting linux 2.6 in qemu-system-ppc

[Johannes Berg]

[-- Attachment #1: Type: text/plain, Size: 238 bytes --]

Hi,

Just for the record: if I remove the VGA card from the qemu pci bus I
can successfully boot a linux 2.6 kernel with serial console. Apparently
there's something wrong with it.

If you want to discuss please CC me.

johannes

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 832 bytes --]

Re: [Qemu-devel] booting linux 2.6 in qemu-system-ppc

[Herbert Poetzl]

On Sun, May 15, 2005 at 02:07:48AM +0200, Johannes Berg wrote:
> Hi,
> 
> Just for the record: if I remove the VGA card from the qemu pci bus I
> can successfully boot a linux 2.6 kernel with serial console. Apparently
> there's something wrong with it.

wrong with what? linux 2.6? the vga card? the serial
console? your kernel config? 

> If you want to discuss please CC me.

best,
Herbert

> johannes



> _______________________________________________
> Qemu-devel mailing list
> Qemu-devel@nongnu.org
> http://lists.nongnu.org/mailman/listinfo/qemu-devel

Re: [Qemu-devel] booting linux 2.6 in qemu-system-ppc

[Johannes Berg]

[-- Attachment #1: Type: text/plain, Size: 427 bytes --]

On Sun, 2005-05-15 at 05:41 +0200, Herbert Poetzl wrote:

> > Just for the record: if I remove the VGA card from the qemu pci bus I
> > can successfully boot a linux 2.6 kernel with serial console. Apparently
> > there's something wrong with it.
> 
> wrong with what? linux 2.6? the vga card? the serial
> console? your kernel config? 

The VGA card I'd say. The kernel crashes while probing the PCI bus.

johannes

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 832 bytes --]

Re: [Qemu-devel] booting linux 2.6 in qemu-system-ppc

[J. Mayer]

On Sun, 2005-05-15 at 02:07 +0200, Johannes Berg wrote:
> Hi,

Hi,

> Just for the record: if I remove the VGA card from the qemu pci bus I
> can successfully boot a linux 2.6 kernel with serial console. Apparently
> there's something wrong with it.

I just checked: I don't have to remove the VGA device to be able to boot
2.6 kernel on serial port. Just have to give it the following arguments
to the kernel (and of course, use a kernel with the PC serial port
support compiled in):
console=ttyS0 console=tty0
Note that the Open-Firmware frame-buffer support is broken in many 2.6
kernels (I mean on real Macs) and that most distributions install CDROM
don't have support for PC serial ports. Then, to be able to have video
console with any 2.6 based distribution, I'm afraid we'll need to have
an ATI Radeon emulation.
You can also notice that we don't emulation Mac serial ports, in Qemu.

-- 
J. Mayer <l_indien@magic.fr>
Never organized

Re: [Qemu-devel] booting linux 2.6 in qemu-system-ppc

[Johannes Berg]

[-- Attachment #1: Type: text/plain, Size: 1048 bytes --]

Hi,

> I just checked: I don't have to remove the VGA device to be able to boot
> 2.6 kernel on serial port. Just have to give it the following arguments
> to the kernel (and of course, use a kernel with the PC serial port
> support compiled in):
> console=ttyS0 console=tty0

Odd. I didn't test with console=tty0 in addition to console=ttyS0. Did
you use the bochs VBE stuff? That works here. Except that both vga cards
manage to kill my xorg xserver, so I'm not really into running with a
vga card.

> Note that the Open-Firmware frame-buffer support is broken in many 2.6
> kernels (I mean on real Macs) and that most distributions install CDROM
> don't have support for PC serial ports. Then, to be able to have video
> console with any 2.6 based distribution, I'm afraid we'll need to have
> an ATI Radeon emulation.
> You can also notice that we don't emulation Mac serial ports, in Qemu.

Yeah, I was testing the kernel so I did it all by myself, including root
(just some busybox stuff) and kernel config.

johannes

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 832 bytes --]

Re: [Qemu-devel] booting linux 2.6 in qemu-system-ppc

[J. Mayer]

On Sun, 2005-05-15 at 14:28 +0200, Johannes Berg wrote: 
> Hi,
> 
> > I just checked: I don't have to remove the VGA device to be able to boot
> > 2.6 kernel on serial port. Just have to give it the following arguments
> > to the kernel (and of course, use a kernel with the PC serial port
> > support compiled in):
> > console=ttyS0 console=tty0
> 
> Odd. I didn't test with console=tty0 in addition to console=ttyS0. Did
> you use the bochs VBE stuff? That works here. Except that both vga cards
> manage to kill my xorg xserver, so I'm not really into running with a
> vga card.

I don't have this problem using XFree (on Debian Sarge). It may be
related to xorg.

> 
> > Note that the Open-Firmware frame-buffer support is broken in many 2.6
> > kernels (I mean on real Macs) and that most distributions install CDROM
> > don't have support for PC serial ports. Then, to be able to have video
> > console with any 2.6 based distribution, I'm afraid we'll need to have
> > an ATI Radeon emulation.
> > You can also notice that we don't emulation Mac serial ports, in Qemu.
> 
> Yeah, I was testing the kernel so I did it all by myself, including root
> (just some busybox stuff) and kernel config.

What I did is  use a Debian Sarge (with a 2.4 kernel) then install a 2.6 kernel.
Everything works all right, then, including XFree.
The only drawback is to have no framebuffer console.
> 
-- 
J. Mayer <l_indien@magic.fr>
Never organized

Re: [Qemu-devel] booting linux 2.6 in qemu-system-ppc

[Benjamin Herrenschmidt]

> console=ttyS0 console=tty0
> Note that the Open-Firmware frame-buffer support is broken in many 2.6
> kernels (I mean on real Macs) 

How so ?

> and that most distributions install CDROM
> don't have support for PC serial ports. Then, to be able to have video
> console with any 2.6 based distribution, I'm afraid we'll need to have
> an ATI Radeon emulation.
> You can also notice that we don't emulation Mac serial ports, in Qemu.
> 

Re: [Qemu-devel] booting linux 2.6 in qemu-system-ppc

[John Reiser]

>>Note that the Open-Firmware frame-buffer support is broken in many 2.6
>>kernels (I mean on real Macs) 

> How so ?

Well, in Fedora Core 4 test 3 (kernels 2.6.11.* and 2.6.12-rc*):
video switching at boot from yaboot with Open Firmware to Tux with
scrolling VGA text is problematic, and switching video from X11 to
VGA-style text virtual consoles does not work at all on my Mac mini.
[On the same hardware, Mac OS X has no problems at all.]  Perhaps
this is just a fumbled handoff _from_ Open Firmware video to direct
video on the hardware, but "support" certainly includes that.

https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=156824
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=156826
https://bugs.freedesktop.org/show_bug.cgi?id=3280

-- 

Re: [Qemu-devel] booting linux 2.6 in qemu-system-ppc

[J. Mayer]

On Mon, 2005-05-23 at 10:31 +1000, Benjamin Herrenschmidt wrote:
> > console=ttyS0 console=tty0
> > Note that the Open-Firmware frame-buffer support is broken in many 2.6
> > kernels (I mean on real Macs) 
> 
> How so ?

Well, there have been many issues with frame-buffer in 2.6, not only on
Mac platform.
With Open-Firmware frame buffer, I remember the first 2.6 kernels had no
fb output at all.
Then came kernels that could display a Tux penguin in psychadelic
colors, I guess it was drawing in 16 bits mode when the OF frame-buffer
is 15 bits.
This has been solved in more recent kernels. I don't remember in which
version it was fixed (but I think around 2.6.5 or 2.6.6).
I can easily reproduce this on my Ibook and on my Apple Network Server,
which means it's not a hardware-dependant bug (Ibook 2 has an ATI
graphic card, ANS is cirrus-logic) nor it's specific to some OF version
(ANS one is really old...).

There is now another bug with qemu: with recent 2.6 kernels, the
frame-buffer is recognized and console is working but it only draws
characters black on black background, even if I send escape sequences to
change the drawing color. Note that the penguin is well drawn, in those
cases.
If you have an idea of what can cause this, I'd be glad to know it ;-)

[...]

-- 
J. Mayer <l_indien@magic.fr>
Never organized

Re: [Qemu-devel] booting linux 2.6 in qemu-system-ppc

[Benjamin Herrenschmidt]

On Mon, 2005-05-23 at 12:47 +0200, J. Mayer wrote:
> On Mon, 2005-05-23 at 10:31 +1000, Benjamin Herrenschmidt wrote:
> > > console=ttyS0 console=tty0
> > > Note that the Open-Firmware frame-buffer support is broken in many 2.6
> > > kernels (I mean on real Macs) 
> > 
> > How so ?
> 
> Well, there have been many issues with frame-buffer in 2.6, not only on
> Mac platform.
> With Open-Firmware frame buffer, I remember the first 2.6 kernels had no
> fb output at all.
> Then came kernels that could display a Tux penguin in psychadelic
> colors, I guess it was drawing in 16 bits mode when the OF frame-buffer
> is 15 bits.
> This has been solved in more recent kernels. I don't remember in which
> version it was fixed (but I think around 2.6.5 or 2.6.6).
> I can easily reproduce this on my Ibook and on my Apple Network Server,
> which means it's not a hardware-dependant bug (Ibook 2 has an ATI
> graphic card, ANS is cirrus-logic) nor it's specific to some OF version
> (ANS one is really old...).
> 
> There is now another bug with qemu: with recent 2.6 kernels, the
> frame-buffer is recognized and console is working but it only draws
> characters black on black background, even if I send escape sequences to
> change the drawing color. Note that the penguin is well drawn, in those
> cases.
> If you have an idea of what can cause this, I'd be glad to know it ;-)

I would say the palette isn't set properly ...

Ben.

Re: [Qemu-devel] booting linux 2.6 in qemu-system-ppc

[J. Mayer]

On Mon, 2005-05-23 at 20:51 +1000, Benjamin Herrenschmidt wrote:
> On Mon, 2005-05-23 at 12:47 +0200, J. Mayer wrote:
> > On Mon, 2005-05-23 at 10:31 +1000, Benjamin Herrenschmidt wrote:
> > > > console=ttyS0 console=tty0
> > > > Note that the Open-Firmware frame-buffer support is broken in many 2.6
> > > > kernels (I mean on real Macs) 
> > > 
> > > How so ?
> > 
> > Well, there have been many issues with frame-buffer in 2.6, not only on
> > Mac platform.
> > With Open-Firmware frame buffer, I remember the first 2.6 kernels had no
> > fb output at all.
> > Then came kernels that could display a Tux penguin in psychadelic
> > colors, I guess it was drawing in 16 bits mode when the OF frame-buffer
> > is 15 bits.
> > This has been solved in more recent kernels. I don't remember in which
> > version it was fixed (but I think around 2.6.5 or 2.6.6).
> > I can easily reproduce this on my Ibook and on my Apple Network Server,
> > which means it's not a hardware-dependant bug (Ibook 2 has an ATI
> > graphic card, ANS is cirrus-logic) nor it's specific to some OF version
> > (ANS one is really old...).
> > 
> > There is now another bug with qemu: with recent 2.6 kernels, the
> > frame-buffer is recognized and console is working but it only draws
> > characters black on black background, even if I send escape sequences to
> > change the drawing color. Note that the penguin is well drawn, in those
> > cases.
> > If you have an idea of what can cause this, I'd be glad to know it ;-)
> 
> I would say the palette isn't set properly ...

Right, is this set according to some OF properties (which could be a
cause of the bug) ?
I didn't find anything like this in OF fb code, but I may have missed
it....

-- 
J. Mayer <l_indien@magic.fr>
Never organized

Re: [Qemu-devel] booting linux 2.6 in qemu-system-ppc

[Benjamin Herrenschmidt]

> Right, is this set according to some OF properties (which could be a
> cause of the bug) ?
> I didn't find anything like this in OF fb code, but I may have missed
> it....

prom_init() sets it using calls to OF fb driver setcolreg method.

Ben.