[PATCH] prom_free_prom_memory for QEMU

[PATCH] prom_free_prom_memory for QEMU

[Atsushi Nemoto]

You can get 60kb more memory by this patch.  Note that this patch
might cause segfault on some intermediate version of qemu 0.9.0 and
0.9.1 (For example Debian qemu-0.9.0+20070816-1).

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
---
diff --git a/arch/mips/qemu/q-mem.c b/arch/mips/qemu/q-mem.c
index dae39b5..84cbee2 100644
--- a/arch/mips/qemu/q-mem.c
+++ b/arch/mips/qemu/q-mem.c
@@ -1,5 +1,9 @@
 #include <linux/init.h>
+#include <asm/bootinfo.h>
+#include <asm/sections.h>
+#include <asm/page.h>
 
 void __init prom_free_prom_memory(void)
 {
+	free_init_pages("prom memory", PAGE_SIZE, __pa_symbol(&_text));
 }

Re: [PATCH] prom_free_prom_memory for QEMU

[Ralf Baechle]

On Mon, Jan 14, 2008 at 09:22:53PM +0900, Atsushi Nemoto wrote:

> You can get 60kb more memory by this patch.  Note that this patch
> might cause segfault on some intermediate version of qemu 0.9.0 and
> 0.9.1 (For example Debian qemu-0.9.0+20070816-1).

I was actually planning to remove the Qemu platform for 2.6.25.  The
Malta emulation has become so good that there is no more point in having
the underfeatured synthetic platform that CONFIG_QEMU is.

Objections?

  Ralf

Re: [PATCH] prom_free_prom_memory for QEMU

[Atsushi Nemoto]

On Mon, 14 Jan 2008 13:37:01 +0000, Ralf Baechle <ralf@linux-mips.org> wrote:
> I was actually planning to remove the Qemu platform for 2.6.25.  The
> Malta emulation has become so good that there is no more point in having
> the underfeatured synthetic platform that CONFIG_QEMU is.
> 
> Objections?

The Qemu platform is one of officially supported platforms by Debian.
If Debian did not support the Malta yet, I hope qemu alive.

---
Atsushi Nemoto

Re: [PATCH] prom_free_prom_memory for QEMU

[Dmitri Vorobiev]

Ralf Baechle wrote:
> On Mon, Jan 14, 2008 at 09:22:53PM +0900, Atsushi Nemoto wrote:
> 
>> You can get 60kb more memory by this patch.  Note that this patch
>> might cause segfault on some intermediate version of qemu 0.9.0 and
>> 0.9.1 (For example Debian qemu-0.9.0+20070816-1).
> 
> I was actually planning to remove the Qemu platform for 2.6.25.  The
> Malta emulation has become so good that there is no more point in having
> the underfeatured synthetic platform that CONFIG_QEMU is.

I wholeheartedly agree with that. It is a godsend to me that I can use
identical configs to build the kernels for QEMU and for a physical Malta.
Emulation is more convenient to me because QEMU boots and runs faster
than the board I'm working with. Many thanks for that to QEMU developers.

Off the topic, how about the plans to remove Atlas support?

Dmitri

> 
> Objections?
> 
>   Ralf
> 
> 

Re: [PATCH] prom_free_prom_memory for QEMU

[Ralf Baechle]

On Mon, Jan 14, 2008 at 10:53:18PM +0900, Atsushi Nemoto wrote:

> On Mon, 14 Jan 2008 13:37:01 +0000, Ralf Baechle <ralf@linux-mips.org> wrote:
> > I was actually planning to remove the Qemu platform for 2.6.25.  The
> > Malta emulation has become so good that there is no more point in having
> > the underfeatured synthetic platform that CONFIG_QEMU is.
> > 
> > Objections?
> 
> The Qemu platform is one of officially supported platforms by Debian.
> If Debian did not support the Malta yet, I hope qemu alive.

A few days ago Thiemo told me Debian dropped the Qemu kernel image.  Malta
otoh is alive and well.

  Ralf

Re: [PATCH] prom_free_prom_memory for QEMU

[Dmitri Vorobiev]

Atsushi Nemoto wrote:
> On Mon, 14 Jan 2008 13:37:01 +0000, Ralf Baechle <ralf@linux-mips.org> wrote:
>> I was actually planning to remove the Qemu platform for 2.6.25.  The
>> Malta emulation has become so good that there is no more point in having
>> the underfeatured synthetic platform that CONFIG_QEMU is.
>>
>> Objections?
> 
> The Qemu platform is one of officially supported platforms by Debian.
> If Debian did not support the Malta yet, I hope qemu alive.

Would you like me to try following the instructions given at

http://www.aurel32.net/info/debian_mips_qemu.php

with QEMU emulating a Malta board? I haven't tried this yet, but I
feel that the possibility exists that this would work out of the box.

Dmitri

> 
> ---
> Atsushi Nemoto
> 
> 

Re: [PATCH] prom_free_prom_memory for QEMU

[Ralf Baechle]

On Mon, Jan 14, 2008 at 04:58:59PM +0300, Dmitri Vorobiev wrote:

> > I was actually planning to remove the Qemu platform for 2.6.25.  The
> > Malta emulation has become so good that there is no more point in having
> > the underfeatured synthetic platform that CONFIG_QEMU is.
> 
> I wholeheartedly agree with that. It is a godsend to me that I can use
> identical configs to build the kernels for QEMU and for a physical Malta.
> Emulation is more convenient to me because QEMU boots and runs faster
> than the board I'm working with. Many thanks for that to QEMU developers.
> 
> Off the topic, how about the plans to remove Atlas support?

Maciej is promising to fix it up since a few years ;-)  Aside of that it's
safe to say the Atlas is dead like a coffin nail.

The main problem with the Atlas is the SAA9730 SOC which is broken in an
infinite number of totally pervert ways, I'm told.  I know of no systems
other than the Atlas using it.

  Ralf

Re: [PATCH] prom_free_prom_memory for QEMU

[Thiemo Seufer]

Dmitri Vorobiev wrote:
> Atsushi Nemoto wrote:
> > On Mon, 14 Jan 2008 13:37:01 +0000, Ralf Baechle <ralf@linux-mips.org> wrote:
> >> I was actually planning to remove the Qemu platform for 2.6.25.  The
> >> Malta emulation has become so good that there is no more point in having
> >> the underfeatured synthetic platform that CONFIG_QEMU is.
> >>
> >> Objections?
> > 
> > The Qemu platform is one of officially supported platforms by Debian.
> > If Debian did not support the Malta yet, I hope qemu alive.
> 
> Would you like me to try following the instructions given at
> 
> http://www.aurel32.net/info/debian_mips_qemu.php
> 
> with QEMU emulating a Malta board? I haven't tried this yet, but I
> feel that the possibility exists that this would work out of the box.

Combining a self-compiled Malta kernel with the Qemu initrd from Debian
works with some minor glitches (like unusable kernel modules in the
installed image). Adding proper support in the Debian installer is
currently ongoing.


Thiemo

Re: [PATCH] prom_free_prom_memory for QEMU

[Thiemo Seufer]

Atsushi Nemoto wrote:
> On Mon, 14 Jan 2008 13:37:01 +0000, Ralf Baechle <ralf@linux-mips.org> wrote:
> > I was actually planning to remove the Qemu platform for 2.6.25.  The
> > Malta emulation has become so good that there is no more point in having
> > the underfeatured synthetic platform that CONFIG_QEMU is.
> > 
> > Objections?
> 
> The Qemu platform is one of officially supported platforms by Debian.
> If Debian did not support the Malta yet, I hope qemu alive.

Debian/unstable had Malta kernels for a while now, installer support
is currently in the works.


Thiemo

Re: [PATCH] prom_free_prom_memory for QEMU

[Atsushi Nemoto]

On Mon, 14 Jan 2008 14:30:33 +0000, Thiemo Seufer <ths@networkno.de> wrote:
> Debian/unstable had Malta kernels for a while now, installer support
> is currently in the works.

Wonderful!  Then I have no objection for dropping QEMU.

---
Atsushi Nemoto

Re: [PATCH] prom_free_prom_memory for QEMU

[Dmitri Vorobiev]

Ralf Baechle wrote:
> On Mon, Jan 14, 2008 at 04:58:59PM +0300, Dmitri Vorobiev wrote:
> 
>>> I was actually planning to remove the Qemu platform for 2.6.25.  The
>>> Malta emulation has become so good that there is no more point in having
>>> the underfeatured synthetic platform that CONFIG_QEMU is.
>> I wholeheartedly agree with that. It is a godsend to me that I can use
>> identical configs to build the kernels for QEMU and for a physical Malta.
>> Emulation is more convenient to me because QEMU boots and runs faster
>> than the board I'm working with. Many thanks for that to QEMU developers.
>>
>> Off the topic, how about the plans to remove Atlas support?
> 
> Maciej is promising to fix it up since a few years ;-)  Aside of that it's
> safe to say the Atlas is dead like a coffin nail.

Well, I could do the proper cleanup, if you give your sayso. As I wrote here
yesterday, I noticed that Malta code was screaming for being put into proper
shape. If MIPS maintainers are interested in applying such janitorial patches,
I could simultaneously wipe the Atlas support off.

So?

> 
> The main problem with the Atlas is the SAA9730 SOC which is broken in an
> infinite number of totally pervert ways, I'm told.  I know of no systems
> other than the Atlas using it.
> 
>   Ralf
> 

Re: [PATCH] prom_free_prom_memory for QEMU

[Ralf Baechle]

On Mon, Jan 14, 2008 at 07:43:12PM +0300, Dmitri Vorobiev wrote:

> >>> I was actually planning to remove the Qemu platform for 2.6.25.  The
> >>> Malta emulation has become so good that there is no more point in having
> >>> the underfeatured synthetic platform that CONFIG_QEMU is.
> >> I wholeheartedly agree with that. It is a godsend to me that I can use
> >> identical configs to build the kernels for QEMU and for a physical Malta.
> >> Emulation is more convenient to me because QEMU boots and runs faster
> >> than the board I'm working with. Many thanks for that to QEMU developers.
> >>
> >> Off the topic, how about the plans to remove Atlas support?
> > 
> > Maciej is promising to fix it up since a few years ;-)  Aside of that it's
> > safe to say the Atlas is dead like a coffin nail.
> 
> Well, I could do the proper cleanup, if you give your sayso. As I wrote here
> yesterday, I noticed that Malta code was screaming for being put into proper
> shape. If MIPS maintainers are interested in applying such janitorial patches,
> I could simultaneously wipe the Atlas support off.
> 
> So?

Of course janitorial patches will be considered.

The Malta code used to scream even way louder.  I made an opportunistic
attempt at fixing the one or other corner over time, whenever something
was getting in my way for some reason.

  Ralf

Re: [PATCH] prom_free_prom_memory for QEMU

[Dmitri Vorobiev]

Ralf Baechle wrote:
> On Mon, Jan 14, 2008 at 07:43:12PM +0300, Dmitri Vorobiev wrote:
> 
>>>>> I was actually planning to remove the Qemu platform for 2.6.25.  The
>>>>> Malta emulation has become so good that there is no more point in having
>>>>> the underfeatured synthetic platform that CONFIG_QEMU is.
>>>> I wholeheartedly agree with that. It is a godsend to me that I can use
>>>> identical configs to build the kernels for QEMU and for a physical Malta.
>>>> Emulation is more convenient to me because QEMU boots and runs faster
>>>> than the board I'm working with. Many thanks for that to QEMU developers.
>>>>
>>>> Off the topic, how about the plans to remove Atlas support?
>>> Maciej is promising to fix it up since a few years ;-)  Aside of that it's
>>> safe to say the Atlas is dead like a coffin nail.
>> Well, I could do the proper cleanup, if you give your sayso. As I wrote here
>> yesterday, I noticed that Malta code was screaming for being put into proper
>> shape. If MIPS maintainers are interested in applying such janitorial patches,
>> I could simultaneously wipe the Atlas support off.
>>
>> So?
> 
> Of course janitorial patches will be considered.

I'm rolling up the sleeves.

> 
> The Malta code used to scream even way louder.  I made an opportunistic
> attempt at fixing the one or other corner over time, whenever something
> was getting in my way for some reason.

I see. Actually, I am teaching system programming at the premises of the Moscow
State University and I am now working on a lab assignment where a Malta board
will be involved. In the classes, I insist that my students follow the coding
style rules to the letter, that's why I really want the Malta code to be 
worthy of imitation.  :)

> 
>   Ralf
>