OpenBIOS PowerPC missing open firmware commands

[Alexander von Gluck]

Just a few things I noticed while hacking away at Haiku on PowerPC:

The following OpenFirmware commands aren't implemented:

erase-screen
toggle-cursor

The following paths are missing essential information:

cpu node -> clock-frequency
cpu node -> timebase-frequency
cpu node -> bus-frequency

Example:

cd /
cd cpus
cd PowerPC,750@0
.properties

These properties are present on real PowerPC hardware, but are set to 0 
(or missing in the case of bus-frequency) on the qemu OpenBIOS.

Thoughts?

Thanks!
  -- Alex

[Alexander von Gluck]

On Mon, 18 Jul 2011 23:39:00 -0500, Alexander von Gluck wrote:
> Just a few things I noticed while hacking away at Haiku on PowerPC:
>
> The following OpenFirmware commands aren't implemented:
>
> erase-screen
> toggle-cursor

It does seem like these are implemented after looking at the sources.
However we receive the following error when they are used:

undefined defer word toggle-cursor
undefined defer word erase-screen

Here is the example usage:
http://dev.haiku-os.org/browser/haiku/trunk/src/system/boot/platform/openfir...
http://dev.haiku-os.org/browser/haiku/trunk/src/system/boot/platform/openfir...

(this all works 100% on real hardware)
> The following paths are missing essential information:
>
> cpu node -> clock-frequency
> cpu node -> timebase-frequency
> cpu node -> bus-frequency
>
> Example:
>
> cd /
> cd cpus
> cd PowerPC,750@0
> .properties

I was a little off in this, the only one *really* missing is the 
bus-frequency.
We can work around the 0 values.

I threw together a patch at the url below to make OpenBIOS a little 
more
OpenFirmware like under qemu:

http://pastebin.com/CkdeEFWL

I'm not sure on how to use the fw_cfg_* portions so I just set it to 0 
for the
moment.

Thanks!
  -- Alex

[Andreas Färber]

Hi Alex,

Am 19.07.2011 um 16:12 schrieb Alexander von Gluck:
> On Mon, 18 Jul 2011 23:39:00 -0500, Alexander von Gluck wrote:
> > Just a few things I noticed while hacking away at Haiku on PowerPC:
> >
> > The following OpenFirmware commands aren't implemented:
> >
> > erase-screen
> > toggle-cursor
>
> It does seem like these are implemented after looking at the sources.
> However we receive the following error when they are used:
>
> undefined defer word toggle-cursor
> undefined defer word erase-screen

I didn't get those when I last tried, it just hung. Where do you see  
these errors?
Please share details on what versions and command line you use. Thanks!
> Here is the example usage:
> http://dev.haiku-os.org/browser/haiku/trunk/src/system/boot/platform/openfir...
> http://dev.haiku-os.org/browser/haiku/trunk/src/system/boot/platform/openfir...
>
> (this all works 100% on real hardware)
> > The following paths are missing essential information:
> >
> > cpu node -> clock-frequency
> > cpu node -> timebase-frequency
> > cpu node -> bus-frequency
> >
> > Example:
> >
> > cd /
> > cd cpus
> > cd PowerPC,750@0
> > .properties
>
> I was a little off in this, the only one *really* missing is the bus- 
> frequency.
> We can work around the 0 values.
>
> I threw together a patch at the url below to make OpenBIOS a little  
> more
> OpenFirmware like under qemu:
>
> http://pastebin.com/CkdeEFWL
>
> I'm not sure on how to use the fw_cfg_* portions so I just set it to  
> 0 for the
> moment.

Without having looked at the URL yet (please prefer posting here for  
offline-reading), the general idea is that QEMU supplies information  
and it is read in the BIOS via fw_cfg.

Andreas

[Alexander von Gluck]

On Tue, 19 Jul 2011 22:56:50 +0200, Andreas Färber wrote:
> Am 19.07.2011 um 16:12 schrieb Alexander von Gluck:
> > On Mon, 18 Jul 2011 23:39:00 -0500, Alexander von Gluck wrote:
> > > Just a few things I noticed while hacking away at Haiku on PowerPC:
> > >
> > > The following OpenFirmware commands aren't implemented:
> > >
> > > erase-screen
> > > toggle-cursor
> >
> > It does seem like these are implemented after looking at the 
> > sources.
> > However we receive the following error when they are used:
> >
> > undefined defer word toggle-cursor
> > undefined defer word erase-screen
>
> I didn't get those when I last tried, it just hung. Where do you see
> these errors?
> Please share details on what versions and command line you use. 
> Thanks!

If you skip doing the new page table...

Index: src/system/boot/platform/openfirmware/arch/ppc/mmu.cpp
===================================================================
--- src/system/boot/platform/openfirmware/arch/ppc/mmu.cpp	(revision 
42449)
+++ src/system/boot/platform/openfirmware/arch/ppc/mmu.cpp	(working 
copy)
@@ -696,7 +696,8 @@
    size_t suggestedTableSize = suggested_page_table_size(total);
    dprintf("suggested page table size = %" B_PRIuSIZE "\n",
    	suggestedTableSize);
-	if (tableSize < suggestedTableSize) {
+	//if (tableSize < suggestedTableSize) {
+	if (0) {
    	// nah, we need a new one!
    	dprintf("need new page table, size = %" B_PRIuSIZE "!\n",
    		suggestedTableSize);

and apply this to your OpenBIOS build...

Index: arch/ppc/qemu/init.c
===================================================================
--- arch/ppc/qemu/init.c	(revision 1045)
+++ arch/ppc/qemu/init.c	(working copy)
@@ -260,6 +260,12 @@
      push_str("clock-frequency");
      fword("property");

+    //PUSH(fw_cfg_read_i32(FW_CFG_PPC_BUSFREQ));
+    PUSH(0);
+    fword("encode-int");
+    push_str("bus-frequency");
+    fword("property");
+
      push_str("running");
      fword("encode-string");
      push_str("state");

You can get all the way to the graphical splash screen for Haiku :)

You will have to press return 3 times in the boot loader menu to load 
the kernel.

qemu-system-ppc -cdrom generated/haiku-boot-cd-ppc.iso -hda 
generated/haiku.image -boot d -cpu G3 -m 512 -nographic
or
qemu-system-ppc -cdrom generated/haiku-boot-cd-ppc.iso -hda 
generated/haiku.image -boot d -cpu G3 -m 512

Thanks!
  -- Alex

[Tarl Neustaedter]

On 2011-Jul-19 10:12 , Alexander von Gluck wrote:
> > The following OpenFirmware commands aren't implemented:
> >
> > erase-screen
> > toggle-cursor
>
> It does seem like these are implemented after looking at the sources.
> However we receive the following error when they are used:
>
> undefined defer word toggle-cursor
> undefined defer word erase-screen

That usually means your Video driver didn't initialize them. The words 
are defined as "defer" words, so they don't point to anything useful 
until a display driver comes by and initializes them. This allows one 
piece of code to be generic and callable from the ok prompt, while to 
unsightly innards are buried in the specific video driver that this 
system has loaded.

It sounds like your display driver didn't initialize them.

[Andreas Färber]

Am 19.07.2011 um 23:06 schrieb Tarl Neustaedter:
> On 2011-Jul-19 10:12 , Alexander von Gluck wrote:
> > > The following OpenFirmware commands aren't implemented:
> > >
> > > erase-screen
> > > toggle-cursor
> >
> > It does seem like these are implemented after looking at the sources.
> > However we receive the following error when they are used:
> >
> > undefined defer word toggle-cursor
> > undefined defer word erase-screen
>
> That usually means your Video driver didn't initialize them. The  
> words are defined as "defer" words, so they don't point to anything  
> useful until a display driver comes by and initializes them. This  
> allows one piece of code to be generic and callable from the ok  
> prompt, while to unsightly innards are buried in the specific video  
> driver that this system has loaded.
>
> It sounds like your display driver didn't initialize them.

Just to verify, your == OpenBIOS' display driver? Or should the OS do  
something?

Andreas

[Tarl Neustaedter]

On 2011-Jul-19 18:14 , Andreas Färber wrote:
> > It sounds like your display driver didn't initialize them.
>
> Just to verify, your == OpenBIOS' display driver? Or should the OS do 
> something?

Correct. Either FCode from a card or some kind of builtin driver that 
Openbios knows to attach to a PCI node.

[Alexander von Gluck]

On Tue, 19 Jul 2011 18:16:27 -0400, Tarl Neustaedter wrote:
> On 2011-Jul-19 18:14 , Andreas Färber wrote:
> > > It sounds like your display driver didn't initialize them.
> >
> > Just to verify, your == OpenBIOS' display driver? Or should the OS 
> > do something?
>
> Correct. Either FCode from a card or some kind of builtin driver that
> Openbios knows to attach to a PCI node.

This doesn't seem right, these commands work on OpenFirmware as-is. 
Their goal is to clear the text OpenBIOS console and toggle the cursor.

Example:

Type:  toggle-cursor at the OpenFirmware prompt on any mac and the 
cursor will disappear / reappear.
        erase-screen and the OpenFirmware screen will erase.

Thanks!
   -- Alex

[Tarl Neustaedter]

On 2011-Jul-19 18:50 , Alexander von Gluck wrote:
> > > > It sounds like your display driver didn't initialize them.
> > >
> > > Just to verify, your == OpenBIOS' display driver? Or should the OS 
> > > do something?
> >
> > Correct. Either FCode from a card or some kind of builtin driver that
> > Openbios knows to attach to a PCI node.
>
> This doesn't seem right, these commands work on OpenFirmware as-is. 
> Their goal is to clear the text OpenBIOS console and toggle the cursor.
>
> Example:
>
> Type:  toggle-cursor at the OpenFirmware prompt on any mac and the 
> cursor will disappear / reappear.
>        erase-screen and the OpenFirmware screen will erase.

Correct. It sounds like the video driver in your environment isn't 
initializing, so these defer words aren't getting set up. The IEEE 1275 
specification indicates these are required to be initialized as part of 
the terminal emulator package, which is the piece of code which knows 
how to translate from text to bits on a screen.

There is a bunch more about this under the fb8-* words in the 
specification, particularly see the fb8-install method.

[Alexander von Gluck]

On Tue, 19 Jul 2011 19:06:05 -0400, Tarl Neustaedter wrote:
> On 2011-Jul-19 18:50 , Alexander von Gluck wrote:
> > > > > It sounds like your display driver didn't initialize them.
> > > >
> > > > Just to verify, your == OpenBIOS' display driver? Or should the OS 
> > > > do something?
> > >
> > > Correct. Either FCode from a card or some kind of builtin driver 
> > > that
> > > Openbios knows to attach to a PCI node.
> >
> > This doesn't seem right, these commands work on OpenFirmware as-is. 
> > Their goal is to clear the text OpenBIOS console and toggle the 
> > cursor.
> >
> > Example:
> >
> > Type:  toggle-cursor at the OpenFirmware prompt on any mac and the 
> > cursor will disappear / reappear.
> >        erase-screen and the OpenFirmware screen will erase.
>
> Correct. It sounds like the video driver in your environment isn't
> initializing, so these defer words aren't getting set up. The IEEE
> 1275 specification indicates these are required to be initialized as
> part of the terminal emulator package, which is the piece of code
> which knows how to translate from text to bits on a screen.
>
> There is a bunch more about this under the fb8-* words in the
> specification, particularly see the fb8-install method.

Thanks for the information. Do you know of a fb8-install method + 
arguments that would work on qemu and real hardware?

Here is the situation:
Our boot menu works on the Apple OpenFirmware implementation as-is 
without fb8-install. (and erase-screen, etc work)
Out boot menu needs fb8-install on OpenBIOS to function (which is the 
correct way from what I gather in the OpenFirmware specs)

Calling fb8-install alone on the Apple hardware (PowerMac 3,5 4.2.5f1) 
seems to cause the screen to lock up an no longer update.
Calling fb8-install alone on OpenBIOS does overlay erase-screen, etc... 
however they don't do anything (see attached)

Thoughts?

Thanks!
  -- Alex

[Tarl Neustaedter]

On 2011-Jul-20 10:58 , Alexander von Gluck wrote:
> Thanks for the information. Do you know of a fb8-install method + 
> arguments that would work on qemu and real hardware?

Unfortunately, I'm not familiar with QEMU itself - my interest in 
OpenBIOS is that I work on OpenBoot (another IEEE 1275 implementation) 
at Sun/Oracle.
> Here is the situation:
> Our boot menu works on the Apple OpenFirmware implementation as-is 
> without fb8-install. (and erase-screen, etc work)

That sounds right. fb8-install is supposed to be called by the video 
driver once things are set up, to define what parameters can be used. 
That something the display driver writes, not you.
> Out boot menu needs fb8-install on OpenBIOS to function (which is the 
> correct way from what I gather in the OpenFirmware specs)

More properly, it sounds like you need a system where the video driver 
has called fb8-install. The point is that your boot menu needs a bunch 
of display-specific methods and whatever video driver QEMU is using 
doesn't seem to have them.
> Calling fb8-install alone on the Apple hardware (PowerMac 3,5 4.2.5f1) 
> seems to cause the screen to lock up an no longer update.

Oh, yeah. Don't do that. Apple probably does something different. 
fb8-install is supposed to be the last step after the video driver has 
set everything up, and they probably install things in some other way. 
fb8-install is probably clobbering whatever they did.
> Calling fb8-install alone on OpenBIOS does overlay erase-screen, 
> etc... however they don't do anything (see attached)

Right. The problem wasn't you failing to call fb8-install, it's display 
driver support for all the video functions you are calling. I pointed 
you at fb8-install simply to get you in the right area - all the other 
fb8-* functions also have to be defined and have to be backed up by a 
display driver that implements them.