On 14 September 2015 at 00:25, Programmingkid <programmingk...@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