Vivek Goyal writes: > On Wed, Jun 25, 2008 at 09:57:05PM +0200, Bernhard Walle wrote: > > This patch adds /sys/firmware/memmap interface that represents the BIOS > > (or Firmware) provided memory map. The tree looks like: > > > > /sys/firmware/memmap/0/start (hex number) > > end (hex number) > > type (string) > > ... /1/start > > end > > type > > > > With the following shell snippet one can print the memory map in the same form > > the kernel prints itself when booting on x86 (the E820 map). > > > > --------- 8< -------------------------- > > #!/bin/sh > > cd /sys/firmware/memmap > > for dir in * ; do > > start=$(cat $dir/start) > > end=$(cat $dir/end) > > type=$(cat $dir/type) > > printf "%016x-%016x (%s)\n" $start $[ $end +1] "$type" > > done > > --------- >8 -------------------------- > > > > That patch only provides the needed interface: > > > > 1. The sysfs interface. > > 2. The structure and enumeration definition. > > 3. The function firmware_map_add() and firmware_map_add_early() > > that should be called from architecture code (E820/EFI, for > > example) to add the contents to the interface. > > > > If the kernel is compiled without CONFIG_FIRMWARE_MEMMAP, the interface does > > nothing without cluttering the architecture-specific code with #ifdef's. > > > > Hi Bernhard, > > Thanks for the patch. Couple of thoughts. > > Do we really need another CONFIG option (CONFIG_FIRMWARE_MEMMAP)? To, > me this does not seem to be a big chunk of code It should be configurable. Whether it's done via CONFIG_KEXEC or its own option I don't care. > at the same time I am > assuming that most of the people will use it (because of kexec). So > probably, it might not make lot of sense to put additional CONFIG option. I question that assumption. Even if (and that's a big if) "most" people use kexec (I don't), Linux is not about forcing unwanted stuff down peoples' throats, we allow knowledgeable users to tune their kernels.
