The ARM architecture version 7 and later mandates that device mappings have the XN (non-executable) bit set, to prevent speculative instruction fetches from read-sensitive regions. This implies that we should not map regions as device if we want to execute from them, so the NOR region that contains our FD image should be mapped as normal memory instead.
The MMU code deals correctly with overlapping ARM_MEMORY_REGION_DESCRIPTOR entries, and later entries in the array take precedence over earlier ones. So simply add an entry to the end of the array that overrides the mapping attributes of the FD image, wherever it resides. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel <ard.biesheu...@linaro.org> --- ArmVirtPkg/Library/ArmVirtPlatformLib/VirtMem.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/ArmVirtPkg/Library/ArmVirtPlatformLib/VirtMem.c b/ArmVirtPkg/Library/ArmVirtPlatformLib/VirtMem.c index d5d288fb1b48..530f7d608e0b 100644 --- a/ArmVirtPkg/Library/ArmVirtPlatformLib/VirtMem.c +++ b/ArmVirtPkg/Library/ArmVirtPlatformLib/VirtMem.c @@ -22,7 +22,7 @@ #include <ArmPlatform.h> // Number of Virtual Memory Map Descriptors -#define MAX_VIRTUAL_MEMORY_MAP_DESCRIPTORS 4 +#define MAX_VIRTUAL_MEMORY_MAP_DESCRIPTORS 5 // DDR attributes #define DDR_ATTRIBUTES_CACHED ARM_MEMORY_REGION_ATTRIBUTE_WRITE_BACK @@ -100,8 +100,14 @@ ArmPlatformGetVirtualMemoryMap ( VirtualMemoryTable[2].Length = ArmGetPhysAddrTop () - VirtualMemoryTable[2].PhysicalBase; VirtualMemoryTable[2].Attributes = ARM_MEMORY_REGION_ATTRIBUTE_DEVICE; + // Remap the FD region as normal executable memory + VirtualMemoryTable[3].PhysicalBase = FixedPcdGet64 (PcdFdBaseAddress); + VirtualMemoryTable[3].VirtualBase = VirtualMemoryTable[3].PhysicalBase; + VirtualMemoryTable[3].Length = FixedPcdGet32 (PcdFdSize); + VirtualMemoryTable[3].Attributes = CacheAttributes; + // End of Table - ZeroMem (&VirtualMemoryTable[3], sizeof (ARM_MEMORY_REGION_DESCRIPTOR)); + ZeroMem (&VirtualMemoryTable[4], sizeof (ARM_MEMORY_REGION_DESCRIPTOR)); *VirtualMemoryMap = VirtualMemoryTable; } -- 1.9.1 _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
