On 14 September 2015 at 00:25, Programmingkid programmingkidx@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