On Sep 11, 2015, at 12:00 PM, qemu-discuss-request@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.