On Thu, Jan 31, 2019 at 2:55 AM Peter Mamonov <pmamonov@xxxxxxxxx> wrote: > > Hello, Andrey, > > > In order to allow access to second half of address space on 64-bit > > machines, add code that creates /dev/highmem dedicated for that. > > > > Note that due to maximum file size being limited to MAX_LFS_FILESIZE > > or 0x7fff_ffff_ffff_ffff bytes at addresses 0x7fff_ffff_ffff_ffff and > > 0xffff_ffff_ffff_ffff cannot be access through /dev/mem and > > /dev/hightmem correspondingly. > > Does it imply using `-s /dev/highmem` argument when accessing addresses beyond > MAX_LFS_FILESIZE? Yes, it does. > That's not very convenient: > > $ git grep -l /dev/mem > commands/crc.c > commands/digest.c > commands/disasm.c > commands/md.c > commands/memcmp.c > commands/memcpy.c > commands/memset.c > commands/mm.c > commands/mw.c > I don't disagree, but there isn't much that can be done about that AFAICT. The first version of this fix kept single /dev/mem file, but ended up introducing quite a bit of special cases all over the FS layer, so it was rejected. The only two options to make it more convenient that I can see would be to either modify "/dev/mem" users to make "/dev/highmem" substitution automatically based on offset they are given, or, assuming it is possible, create a mapping that would expose all of the interesting registers on MIPS64 in the lower half of 64-bit address space. Thanks, Andrey Smirnov _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
