On 07/11/2013 03:22 PM, Chris Friesen wrote: > On 07/11/2013 02:55 PM, Chris Friesen wrote: >> Hi, >> >> I'm running 2.6.34 with kexec 2.0.1 on a Freescale p5020-based system >> with 8GB of memory. (It's an embedded system and I can't do much >> about the fact that it's using older software.) > > I should probably clarify this...I may be able to update kexec, I can't > update the kernel but I can backport more recent code if necessary. > > Looking at the version of kexec that I have, it seems like where x86 > uses "memmap=" to specify the memory map usable by the capture kernel, > powerpc does something different. After some experimenting, it looks like in the capture kernel /dev/oldmem might actually refer to the memory owned by the old kernel. However, there doesn't seem to be anything preventing me from trampling it from within the capture kernel--I can create a tmpfs filesystem in memory and write gigs of data to it even though the capture kernel is only supposed to have 224MB. I think I got it to work properly once, but since then I haven't been able to get uncorrupted data out of /dev/oldmem. (My original kernel reserves a chunk of memory for logging and passes the offset/size to the capture kernel via kexec kernel args.) Chris
