Commit Graph

3 Commits

Author SHA1 Message Date
Bin Meng
3b621ccabd x86: Test mtrr support flag before accessing mtrr msr
On some x86 processors (like Intel Quark) the MTRR registers are not
supported. This is reflected by the CPUID (EAX 01H) result EDX[12].
Accessing the MTRR registers on such processors will cause #GP so we
must test the support flag before accessing MTRR MSRs.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
2015-01-23 17:24:55 -07:00
Bin Meng
566d1754d3 x86: Add missing DECLARE_GLOBAL_DATA_PTR for mtrr.c
arch/x86/cpu/mtrr.c has access to the U-Boot global data thus
DECLARE_GLOBAL_DATA_PTR is needed.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
2015-01-23 17:24:54 -07:00
Simon Glass
aff2523f69 x86: Add support for MTRRs
Memory Type Range Registers are used to tell the CPU whether memory is
cacheable and if so the cache write mode to use.

Clean up the existing header file to follow style, and remove the unneeded
code.

These can speed up booting so should be supported. Add these to global_data
so they can be requested while booting. We will apply the changes during
relocation (in a later commit).

Signed-off-by: Simon Glass <sjg@chromium.org>
2015-01-13 07:25:00 -08:00