@@ -55,6 +55,7 @@
PrePiHobListPointerLib
PlatformPeiLib
MemoryInitPeiLib
+ CacheMaintenanceLib
[Ppis]
gArmMpCoreInfoPpiGuid
@@ -20,6 +20,7 @@
#include <Library/PrePiHobListPointerLib.h>
#include <Library/TimerLib.h>
#include <Library/PerformanceLib.h>
+#include <Library/CacheMaintenanceLib.h>
#include <Ppi/GuidedSectionExtraction.h>
#include <Ppi/ArmMpCoreInfo.h>
@@ -102,12 +103,6 @@ PrePiMain (
// Initialize the architecture specific bits
ArchInitialize ();
- // Initialize the Serial Port
- SerialPortInitialize ();
- CharCount = AsciiSPrint (Buffer,sizeof (Buffer),"UEFI firmware (version %s built at %a on %a)\n\r",
- (CHAR16*)PcdGetPtr(PcdFirmwareVersionString), __TIME__, __DATE__);
- SerialPortWrite ((UINT8 *) Buffer, CharCount);
-
// Declare the PI/UEFI memory region
HobList = HobConstructor (
(VOID*)UefiMemoryBase,
@@ -117,10 +112,23 @@ PrePiMain (
);
PrePeiSetHobList (HobList);
+ //
+ // Ensure that the loaded image is invalidated in the caches, so that any
+ // modifications we made with the caches and MMU off (such as the applied
+ // relocations) don't become invisible once we turn them on.
+ //
+ InvalidateDataCacheRange((VOID *)(UINTN)PcdGet64 (PcdFdBaseAddress), PcdGet32 (PcdFdSize));
+
// Initialize MMU and Memory HOBs (Resource Descriptor HOBs)
Status = MemoryPeim (UefiMemoryBase, FixedPcdGet32 (PcdSystemMemoryUefiRegionSize));
ASSERT_EFI_ERROR (Status);
+ // Initialize the Serial Port
+ SerialPortInitialize ();
+ CharCount = AsciiSPrint (Buffer,sizeof (Buffer),"UEFI firmware (version %s built at %a on %a)\n\r",
+ (CHAR16*)PcdGetPtr(PcdFirmwareVersionString), __TIME__, __DATE__);
+ SerialPortWrite ((UINT8 *) Buffer, CharCount);
+
// Create the Stacks HOB (reserve the memory for all stacks)
StacksSize = PcdGet32 (PcdCPUCorePrimaryStackSize);
BuildStackHob (StacksBase, StacksSize);
In order to prevent memory corruption issues caused by the fact that, under virtualization, the guest is incoherent with the hypervisor's view of memory until it enables its caches and MMU, this patch reshuffles the init sequence so that the Xen shared memory regions are not touched before the caches and MMU are enabled. In addition, the loaded image itself is invalidated by virtual address, to ensure that any runtime changes we make with the caches off (such as applying the ELF relocations) will not suddenly become invisible once we turn the caches on. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- .../PrePi/ArmVirtPrePiUniCoreRelocatable.inf | 1 + ArmPlatformPkg/ArmVirtualizationPkg/PrePi/PrePi.c | 20 ++++++++++++++------ 2 files changed, 15 insertions(+), 6 deletions(-)