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>
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>
We don't need this in U-Boot since we calculate it based on available memory.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Add support for CAR so that we have memory to use prior to DRAM init.
On link there is a total of 128KB of CAR available, although some is
used for the memory reference code.
Signed-off-by: Simon Glass <sjg@chromium.org>
Bin Meng
Simon Glass
Masahiro Yamada
Wolfgang Denk
Graeme Russ