There was a restriction that KERNEL_VM_OFFSET must equal to
SRAM_OFFSET so that page directory pointer (PDP) or page
directory (PD) can be reused. This is not very practical in
real world due to various hardware designs, especially those
where SRAM is not aligned to PDP or PD. So rework those bits.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This adds the bits to the gen_mmu.py script so that extra mappings
can be added with caching disabled. This is useful for mapping
MMIO regions where caching is not desired.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This adds to page on the x86 virtual memory about how to specify
extra page table mappings during build.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>