NAME    [Toc]    [Back]

     memconfig - control system cache behaviour with  respect  to
memory

SYNOPSIS    [Toc]    [Back]

     memconfig list [-a]
     memconfig set -b base -l length -o owner attribute
     memconfig clear -o owner
     memconfig clear -b base -l length

DESCRIPTION    [Toc]    [Back]

     A  number  of  supported  system architectures allow the behaviour of the CPU
     cache to be programmed to behave  differently  depending  on
the region being
 written.

     memconfig  provides  an interface to this facility, allowing
CPU cache behavior
 to be altered for ranges of system physical memory.

     These ranges are typically  power-of-2  aligned  and  sized,
however the specific
  rules  governing  their layout vary between architectures.  The
     memconfig program does not attempt to enforce  these  rules,
however the
     system  will  reject  any attempt to set an illegal combination.

     The operands and their options are as follows:

     list   List range slots.

            [-a]    List all range slots, even those that are inactive.

     set    Set memory range attributes.

            -b base
                    Memory range base address.

            -l length
                    Length  of memory range in bytes, power of 2.

            -o owner
                    Text identifier  for  this  setting  (7  char
max).

            attribute
                    Attributes  applied  to  this range; combinations of force,
                    uncacheable,  write-combine,   write-through,
write-back, or
                    write-protect.

     clear  Clear memory range attributes.  Ranges may be cleared
by owner or
            by base/length combination.

            To clear based on ownership:

            -o owner
                    All ranges with this owner will be cleared.

            To clear based on the base/length combination:

            -b base
                    Memory range base address.

            -l length
                    Length of memory range in bytes, power of  2.

            Base and length must exactly match an existing range.

SEE ALSO    [Toc]    [Back]

     mtrr(4)

HISTORY    [Toc]    [Back]

     memconfig was originally introduced in FreeBSD 3.3  as  memcontrol.

OpenBSD      3.6                        November     14,     1999