From: Andrew Jones <drjones@xxxxxxxxxx> This will be used by future change to add PTE entries for special EFI memory regions. Signed-off-by: Nikos Nikoleris <nikos.nikoleris@xxxxxxx> Reviewed-by: Ricardo Koller <ricarkol@xxxxxxxxxx> --- lib/arm/asm/setup.h | 1 + lib/arm/mmu.c | 4 ++++ 2 files changed, 5 insertions(+) diff --git a/lib/arm/asm/setup.h b/lib/arm/asm/setup.h index f0e70b11..64cd379b 100644 --- a/lib/arm/asm/setup.h +++ b/lib/arm/asm/setup.h @@ -15,6 +15,7 @@ extern int nr_cpus; #define MR_F_IO (1U << 0) #define MR_F_CODE (1U << 1) +#define MR_F_RESERVED (1U << 2) #define MR_F_UNKNOWN (1U << 31) struct mem_region { diff --git a/lib/arm/mmu.c b/lib/arm/mmu.c index 18e32b2b..2f4ec815 100644 --- a/lib/arm/mmu.c +++ b/lib/arm/mmu.c @@ -222,6 +222,10 @@ void *setup_mmu(phys_addr_t phys_end, void *unused) for (r = mem_regions; r->end; ++r) { if (r->flags & MR_F_IO) { continue; + } else if (r->flags & MR_F_RESERVED) { + /* Reserved pages need to be writable for whatever reserved them */ + mmu_set_range_ptes(mmu_idmap, r->start, r->start, r->end, + __pgprot(PTE_WBWA)); } else if (r->flags & MR_F_CODE) { /* armv8 requires code shared between EL1 and EL0 to be read-only */ mmu_set_range_ptes(mmu_idmap, r->start, r->start, r->end, -- 2.25.1