Re: [OpenBIOS] [Qemu-discuss] Qemu-system-sparc: What would I need to change to add functionality to save the nvram content between boots ?

[Programmingkid]

On Sep 11, 2015, at 12:00 PM, qemu-discuss-request(a)nongnu.org wrote:

  On 10/09/2015 8:58 AM, Maximilian H. wrote:
  Hello,
 
 I was looking into what parts would need change to save and restore the
 nvram content for the qemu-system-sparc vm between boots.
 
 I see the code in hw/timer/m48t59.c that implements the nvram.
 
 So some questions arise, and before I spend too much time poking around
 the still unknown code, I'd thought I ask first.
 
 1. Command line processing starts in vl.c in the main fct there ? Can I
 add a command line argument there, say "-sparcnvram" ?
 
 2. In hw/timer/m48t59.c has no functionality that I see from having a
 look at it (not in depth) to save or restore the nvram's contents for
 sparc. Is there a general facility that qemu has that provides such a
 functionality - i.e. is there a general qemu save and restore framework ?
 
 3. Is there an example somebody could point me to that implements
 something similar ? Imitation is the sincerest of flattery ....
 
 4. All the alarm and watchdog functionality that the m48t08 provides, is
 that used on sparc too ?
 
 5. Besides what is in
 http://wiki.qemu.org/Documentation/GettingStartedDevelopers, is there
 some qemu coding documentation to make it faster for somebody unfamilar
 with qemu's code like me to be able to implement something ? I'd like to
 spend a few evenings on this, produce a patch and move on.
 
 Thanks
 BR
 Max.

This sounds like a good idea. Having OpenBIOS settings actually be saved between boots
would make things more real. 

Mark, do you think it is possible for a QEMU command line option to actually load the
saved OpenBIOS settings from a file and restore them into memory? I'm thinking
something
along the lines of -prom-memory <file name>. 

Max, there is a project that you should probably look at called OpenBIOS. It implements
an implementation of Open Firmware. Here is where more info can be found:
http://www.openfirmware.info/Welcome_to_OpenBIOS. If you do want to implement this
feature,
it would help to know how the BIOS is implemented.

[Qemu-discuss] Qemu-system-sparc: What would I need to change to add functionality to save the nvram content between boots ?

[Laurent Vivier]

Le 11/09/2015 20:01, Programmingkid a écrit :
  
 On Sep 11, 2015, at 12:00 PM, qemu-discuss-request(a)nongnu.org
 <mailto:[e-mail]> wrote:
 
  On 10/09/2015 8:58 AM, Maximilian H. wrote:
  Hello,

 I was looking into what parts would need change to save and restore the
 nvram content for the qemu-system-sparc vm between boots.

 I see the code in hw/timer/m48t59.c that implements the nvram.

 So some questions arise, and before I spend too much time poking around
 the still unknown code, I'd thought I ask first.

 1. Command line processing starts in vl.c in the main fct there ? Can I
 add a command line argument there, say "-sparcnvram" ?

 2. In hw/timer/m48t59.c has no functionality that I see from having a
 look at it (not in depth) to save or restore the nvram's contents for
 sparc. Is there a general facility that qemu has that provides such a
 functionality - i.e. is there a general qemu save and restore framework ?

 3. Is there an example somebody could point me to that implements
 something similar ? Imitation is the sincerest of flattery ....

 4. All the alarm and watchdog functionality that the m48t08 provides, is
 that used on sparc too ?

 5. Besides what is in
 http://wiki.qemu.org/Documentation/GettingStartedDevelopers, is there
 some qemu coding documentation to make it faster for somebody unfamilar
 with qemu's code like me to be able to implement something ? I'd like to
 spend a few evenings on this, produce a patch and move on.

 Thanks
 BR
 Max.
 
 This sounds like a good idea. Having OpenBIOS settings actually be saved
 between boots
 would make things more real. 
 
 Mark, do you think it is possible for a QEMU command line option to
 actually load the
 saved OpenBIOS settings from a file and restore them into memory? I'm
 thinking something
 along the lines of -prom-memory <file name>.
Nostalgia: a seven years old thread, out of date now:

https://lists.gnu.org/archive/html/qemu-devel/2008-05/msg00002.html

  
 Max, there is a project that you should probably look at called
 OpenBIOS. It implements
 an implementation of Open Firmware. Here is where more info can be
 found: http://www.openfirmware.info/Welcome_to_OpenBIOS. If you do want
 to implement this feature,
 it would help to know how the BIOS is implemented.
Laurent

[Qemu-discuss] Qemu-system-sparc: What would I need to change to add functionality to save the nvram content between boots ?

[Programmingkid]

On Sep 11, 2015, at 4:09 PM, Laurent Vivier wrote:

  
 
 Le 11/09/2015 20:01, Programmingkid a écrit :
  
 On Sep 11, 2015, at 12:00 PM, qemu-discuss-request(a)nongnu.org
 <mailto:[e-mail]> wrote:
 
  On 10/09/2015 8:58 AM, Maximilian H. wrote:
  Hello,
 
 I was looking into what parts would need change to save and restore the
 nvram content for the qemu-system-sparc vm between boots.
 
 I see the code in hw/timer/m48t59.c that implements the nvram.
 
 So some questions arise, and before I spend too much time poking around
 the still unknown code, I'd thought I ask first.
 
 1. Command line processing starts in vl.c in the main fct there ? Can I
 add a command line argument there, say "-sparcnvram" ?
 
 2. In hw/timer/m48t59.c has no functionality that I see from having a
 look at it (not in depth) to save or restore the nvram's contents for
 sparc. Is there a general facility that qemu has that provides such a
 functionality - i.e. is there a general qemu save and restore framework ?
 
 3. Is there an example somebody could point me to that implements
 something similar ? Imitation is the sincerest of flattery ....
 
 4. All the alarm and watchdog functionality that the m48t08 provides, is
 that used on sparc too ?
 
 5. Besides what is in
 http://wiki.qemu.org/Documentation/GettingStartedDevelopers, is there
 some qemu coding documentation to make it faster for somebody unfamilar
 with qemu's code like me to be able to implement something ? I'd like to
 spend a few evenings on this, produce a patch and move on.
 
 Thanks
 BR
 Max.
 
 This sounds like a good idea. Having OpenBIOS settings actually be saved
 between boots
 would make things more real. 
 
 Mark, do you think it is possible for a QEMU command line option to
 actually load the
 saved OpenBIOS settings from a file and restore them into memory? I'm
 thinking something
 along the lines of -prom-memory <file name>.
 
 Nostalgia: a seven years old thread, out of date now:
 
 https://lists.gnu.org/archive/html/qemu-devel/2008-05/msg00002.html
 
  
 Max, there is a project that you should probably look at called
 OpenBIOS. It implements
 an implementation of Open Firmware. Here is where more info can be
 found: http://www.openfirmware.info/Welcome_to_OpenBIOS. If you do want
 to implement this feature,
 it would help to know how the BIOS is implemented.
 
 Laurent
Could you send the patch please?

[Qemu-discuss] Qemu-system-sparc: What would I need to change to add functionality to save the nvram content between boots ?

[Laurent Vivier]

Le 11/09/2015 23:07, Programmingkid a écrit :
  
 On Sep 11, 2015, at 4:09 PM, Laurent Vivier wrote:
 
 

 Le 11/09/2015 20:01, Programmingkid a écrit :
 
 On Sep 11, 2015, at 12:00 PM, qemu-discuss-request(a)nongnu.org
 <mailto:[e-mail]> wrote:

  On 10/09/2015 8:58 AM, Maximilian H. wrote:
> Hello,
>
> I was looking into what parts would need change to save and restore the
> nvram content for the qemu-system-sparc vm between boots.
>
> I see the code in hw/timer/m48t59.c that implements the nvram.
>
> So some questions arise, and before I spend too much time poking around
> the still unknown code, I'd thought I ask first.
>
> 1. Command line processing starts in vl.c in the main fct there ? Can I
> add a command line argument there, say "-sparcnvram" ?
>
> 2. In hw/timer/m48t59.c has no functionality that I see from having a
> look at it (not in depth) to save or restore the nvram's contents for
> sparc. Is there a general facility that qemu has that provides such a
> functionality - i.e. is there a general qemu save and restore framework ?
>
> 3. Is there an example somebody could point me to that implements
> something similar ? Imitation is the sincerest of flattery ....
>
> 4. All the alarm and watchdog functionality that the m48t08 provides, is
> that used on sparc too ?
>
> 5. Besides what is in
> http://wiki.qemu.org/Documentation/GettingStartedDevelopers, is there
> some qemu coding documentation to make it faster for somebody unfamilar
> with qemu's code like me to be able to implement something ? I'd like to
> spend a few evenings on this, produce a patch and move on.
>
> Thanks
> BR
> Max.
 This sounds like a good idea. Having OpenBIOS settings actually be saved
 between boots
 would make things more real. 

 Mark, do you think it is possible for a QEMU command line option to
 actually load the
 saved OpenBIOS settings from a file and restore them into memory? I'm
 thinking something
 along the lines of -prom-memory <file name>.
 Nostalgia: a seven years old thread, out of date now:

 https://lists.gnu.org/archive/html/qemu-devel/2008-05/msg00002.html

 
 Max, there is a project that you should probably look at called
 OpenBIOS. It implements
 an implementation of Open Firmware. Here is where more info can be
 found: http://www.openfirmware.info/Welcome_to_OpenBIOS. If you do want
 to implement this feature,
 it would help to know how the BIOS is implemented.
 Laurent
 
 Could you send the patch please?
The patch is attached to the mail in the thread. Anyway, I don't think
it applies now.

Laurent

[Qemu-discuss] Qemu-system-sparc: What would I need to change to add functionality to save the nvram content between boots ?

[Programmingkid]

On Sep 12, 2015, at 3:46 AM, Laurent Vivier wrote:

  
 
 Le 11/09/2015 23:07, Programmingkid a écrit :
  
 On Sep 11, 2015, at 4:09 PM, Laurent Vivier wrote:
 
  
 
 Le 11/09/2015 20:01, Programmingkid a écrit :
  
 On Sep 11, 2015, at 12:00 PM, qemu-discuss-request(a)nongnu.org
 <mailto:[e-mail]> wrote:
 
> On 10/09/2015 8:58 AM, Maximilian H. wrote:
>> Hello,
>> 
>> I was looking into what parts would need change to save and restore the
>> nvram content for the qemu-system-sparc vm between boots.
>> 
>> I see the code in hw/timer/m48t59.c that implements the nvram.
>> 
>> So some questions arise, and before I spend too much time poking around
>> the still unknown code, I'd thought I ask first.
>> 
>> 1. Command line processing starts in vl.c in the main fct there ? Can I
>> add a command line argument there, say "-sparcnvram" ?
>> 
>> 2. In hw/timer/m48t59.c has no functionality that I see from having a
>> look at it (not in depth) to save or restore the nvram's contents for
>> sparc. Is there a general facility that qemu has that provides such a
>> functionality - i.e. is there a general qemu save and restore framework ?
>> 
>> 3. Is there an example somebody could point me to that implements
>> something similar ? Imitation is the sincerest of flattery ....
>> 
>> 4. All the alarm and watchdog functionality that the m48t08 provides, is
>> that used on sparc too ?
>> 
>> 5. Besides what is in
>> http://wiki.qemu.org/Documentation/GettingStartedDevelopers, is there
>> some qemu coding documentation to make it faster for somebody unfamilar
>> with qemu's code like me to be able to implement something ? I'd like to
>> spend a few evenings on this, produce a patch and move on.
>> 
>> Thanks
>> BR
>> Max.
> 
 
 This sounds like a good idea. Having OpenBIOS settings actually be saved
 between boots
 would make things more real. 
 
 Mark, do you think it is possible for a QEMU command line option to
 actually load the
 saved OpenBIOS settings from a file and restore them into memory? I'm
 thinking something
 along the lines of -prom-memory <file name>.
 
 Nostalgia: a seven years old thread, out of date now:
 
 https://lists.gnu.org/archive/html/qemu-devel/2008-05/msg00002.html
 
  
 Max, there is a project that you should probably look at called
 OpenBIOS. It implements
 an implementation of Open Firmware. Here is where more info can be
 found: http://www.openfirmware.info/Welcome_to_OpenBIOS. If you do want
 to implement this feature,
 it would help to know how the BIOS is implemented.
 
 Laurent
 
 Could you send the patch please?
 
 The patch is attached to the mail in the thread. Anyway, I don't think
 it applies now.
 
 Laurent
The extension on the patch is incorrectly set to .bin. Had to change it to .txt to make it
work. Thanks.
I don't have the original poster's email address so I can't send it to him.
Hopefully he had read these
emails and knows about it.

[Qemu-discuss] Qemu-system-sparc: What would I need to change to add functionality to save the nvram content between boots ?

[Mark Cave-Ayland]

On 11/09/15 19:01, Programmingkid wrote:

  On Sep 11, 2015, at 12:00 PM,
qemu-discuss-request(a)nongnu.org
 <mailto:[e-mail]> wrote:
 
  On 10/09/2015 8:58 AM, Maximilian H. wrote:
  Hello,

 I was looking into what parts would need change to save and restore the
 nvram content for the qemu-system-sparc vm between boots.

 I see the code in hw/timer/m48t59.c that implements the nvram.

 So some questions arise, and before I spend too much time poking around
 the still unknown code, I'd thought I ask first.

 1. Command line processing starts in vl.c in the main fct there ? Can I
 add a command line argument there, say "-sparcnvram" ?

 2. In hw/timer/m48t59.c has no functionality that I see from having a
 look at it (not in depth) to save or restore the nvram's contents for
 sparc. Is there a general facility that qemu has that provides such a
 functionality - i.e. is there a general qemu save and restore framework ?

 3. Is there an example somebody could point me to that implements
 something similar ? Imitation is the sincerest of flattery ....

 4. All the alarm and watchdog functionality that the m48t08 provides, is
 that used on sparc too ?

 5. Besides what is in
 http://wiki.qemu.org/Documentation/GettingStartedDevelopers, is there
 some qemu coding documentation to make it faster for somebody unfamilar
 with qemu's code like me to be able to implement something ? I'd like to
 spend a few evenings on this, produce a patch and move on.

 Thanks
 BR
 Max.
 
 This sounds like a good idea. Having OpenBIOS settings actually be saved
 between boots
 would make things more real. 
 
 Mark, do you think it is possible for a QEMU command line option to
 actually load the
 saved OpenBIOS settings from a file and restore them into memory? I'm
 thinking something
 along the lines of -prom-memory <file name>. 
 
 Max, there is a project that you should probably look at called
 OpenBIOS. It implements
 an implementation of Open Firmware. Here is where more info can be
 found: http://www.openfirmware.info/Welcome_to_OpenBIOS. If you do want
 to implement this feature,
 it would help to know how the BIOS is implemented.
 From memory the reason this hasn't been done is
because the NVRAM
interface is used across multiple architectures and there
hasn't been a
solution devised that would work well enough for all of them. Then again
as the BIOSs involved have continued to develop, it may be now that some
of the issues can now be solved so it never hurts to ask on the -devel list.

May I ask why you want to save the NVRAM state between boots on SPARC?
My guess would be that you're using a real SS-5 PROM image and looking
to avoid having to type boot commands into the terminal after every
reset. If this is the case then you may be pleasantly surprised using
QEMU 2.4 with the built-in OpenBIOS as there were fixes applied during
the last development cycle that were enough to allow SunOS 4.1.4 to boot.

If this solution works for you and you are keen use the alarm/watchdog
features then there may be some scope to add the required features to
QEMU/OpenBIOS in future.


ATB,

Mark.

[Qemu-discuss] Qemu-system-sparc: What would I need to change to add functionality to save the nvram content between boots ?

[Bodo Eggert]

On Sun, 13 Sep 2015, Mark Cave-Ayland wrote:
  On 11/09/15 19:01, Programmingkid wrote:
  > Mark, do you think it is possible for a QEMU
command line option to
 > actually load the
 > saved OpenBIOS settings from a file and restore them into memory? I'm
 > thinking something
 > along the lines of -prom-memory <file name>.
 From memory the
reason this hasn't been done is because the NVRAM
 interface is used across
multiple architectures and there hasn't been a
 solution devised that would work well enough for all of them. Then again
 as the BIOSs involved have continued to develop, it may be now that some
 of the issues can now be solved so it never hurts to ask on the -devel list.
I'm wondering, why wouldn't it be enough to memmap a nvram file instead of 
mallocing (or whatever) the memory area?

[Qemu-discuss] Qemu-system-sparc: What would I need to change to add functionality to save the nvram content between boots ?

[Programmingkid]

On Sep 13, 2015, at 5:50 PM, Bodo Eggert wrote:

  On Sun, 13 Sep 2015, Mark Cave-Ayland wrote:
  On 11/09/15 19:01, Programmingkid wrote:
 
 > Mark, do you think it is possible for a QEMU
command line option to
> actually load the
> saved OpenBIOS settings from a file and restore them into memory? I'm
> thinking something
> along the lines of -prom-memory <file name>.
 
  From
memory the reason this hasn't been done is because the NVRAM
 interface is used
across multiple architectures and there hasn't been a
 solution devised that would work well enough for all of them. Then again
 as the BIOSs involved have continued to develop, it may be now that some
 of the issues can now be solved so it never hurts to ask on the -devel list.
 
 I'm wondering, why wouldn't it be enough to memmap a nvram file instead of 
 mallocing (or whatever) the memory area?
What advantage does mmap() have over malloc()? I think malloc() is a lot more
familiar to use than mmap().

[Qemu-discuss] Qemu-system-sparc: What would I need to change to add functionality to save the nvram content between boots ?

[Bodo Eggert]

On Sun, 13 Sep 2015, Programmingkid wrote:
  On Sep 13, 2015, at 5:50 PM, Bodo Eggert wrote:
 > On Sun, 13 Sep 2015, Mark Cave-Ayland wrote:
 >> On 11/09/15 19:01, Programmingkid wrote:
 > Mark, do you think it is possible for a QEMU
command line option to
> actually load the
> saved OpenBIOS settings from a file and restore them into memory? I'm
> thinking something
> along the lines of -prom-memory <file name>.
 
  From
memory the reason this hasn't been done is because the NVRAM
 interface is used
across multiple architectures and there hasn't been a
 solution devised that would work well enough for all of them. Then again
 as the BIOSs involved have continued to develop, it may be now that some
 of the issues can now be solved so it never hurts to ask on the -devel list.
 
 I'm wondering, why wouldn't it be enough to memmap a nvram file instead of 
 mallocing (or whatever) the memory area?
 
 What advantage does mmap() have over malloc()? I think malloc() is a lot more
 familiar to use than mmap().
The advantage is that it's file-backed (optionally, but intended here).  
Everything you write into that memory area will be automatically 
saved and restored just like a nvram should be. At least, that's what the 
documentation promises, I never used it myself, therefore I ask.

[Qemu-discuss] Qemu-system-sparc: What would I need to change to add functionality to save the nvram content between boots ?

[Programmingkid]

On Sep 13, 2015, at 7:20 PM, Bodo Eggert wrote:

  On Sun, 13 Sep 2015, Programmingkid wrote:
  On Sep 13, 2015, at 5:50 PM, Bodo Eggert wrote:
> On Sun, 13 Sep 2015, Mark Cave-Ayland wrote:
>> On 11/09/15 19:01, Programmingkid wrote:
 
 > Mark, do you think it is possible for a QEMU
command line option to
> actually load the
> saved OpenBIOS settings from a file and restore them into memory? I'm
> thinking something
> along the lines of -prom-memory <file name>.
 
 > From memory the reason this hasn't been
done is because the NVRAM
 interface is used across multiple architectures and there hasn't been a
 solution devised that would work well enough for all of them. Then again
 as the BIOSs involved have continued to develop, it may be now that some
 of the issues can now be solved so it never hurts to ask on the -devel list.
 
 I'm wondering, why wouldn't it be enough to memmap a nvram file instead of 
 mallocing (or whatever) the memory area?
 
 What advantage does mmap() have over malloc()? I think malloc() is a lot more
 familiar to use than mmap().
 
 The advantage is that it's file-backed (optionally, but intended here).  
 Everything you write into that memory area will be automatically 
 saved and restored just like a nvram should be. At least, that's what the 
 documentation promises, I never used it myself, therefore I ask.
You make mmap() sound good. Maybe we should use it.

[Qemu-discuss] Qemu-system-sparc: What would I need to change to add functionality to save the nvram content between boots ?

[Peter Maydell]

On 14 September 2015 at 00:25, Programmingkid <programmingkidx(a)gmail.com> wrote:
 
 On Sep 13, 2015, at 7:20 PM, Bodo Eggert wrote:

  On Sun, 13 Sep 2015, Programmingkid wrote:
  On Sep 13, 2015, at 5:50 PM, Bodo Eggert wrote:
> On Sun, 13 Sep 2015, Mark Cave-Ayland wrote:
>> On 11/09/15 19:01, Programmingkid wrote:
 >>
Mark, do you think it is possible for a QEMU command line option to
>> actually load the
>> saved OpenBIOS settings from a file and restore them into memory? I'm
>> thinking something
>> along the lines of -prom-memory <file name>.

>> From memory the reason this hasn't been done is because the NVRAM
> interface is used across multiple architectures and there hasn't been a
> solution devised that would work well enough for all of them. Then again
> as the BIOSs involved have continued to develop, it may be now that some
> of the issues can now be solved so it never hurts to ask on the -devel list.

 I'm wondering, why wouldn't it be enough to memmap a nvram file instead of
 mallocing (or whatever) the memory area?
 What advantage does mmap() have over malloc()? I think malloc() is a lot more
 familiar to use than mmap().
 The advantage is that it's file-backed (optionally, but intended here).
 Everything you write into that memory area will be automatically
 saved and restored just like a nvram should be. At least, that's what the
 documentation promises, I never used it myself, therefore I ask.
 You make mmap() sound good. Maybe we should use it.
Rather than reinventing the wheel I suggest looking at how QEMU
already supports file-backed ROMs for other platforms...

thanks
-- PMM