Files
system76-edk2/ArmPkg/Library/ArmExceptionLib/AArch64/AArch64Exception.c
Heyi Guo e1d24410da ArmPkg/ArmExceptionLib: use static buffer for sp_el0
The exception library is also used in DxeMain before memory services
are available, and AllocatePages() will fail in this case and cause
sp_el0 remains 0. Then if any exception occurs before CpuDxe driver is
loaded, a recursive exception will be trigged by page translation
fault for sp = 0 - 0x130.

Use static buffer instead to fix this issue.

Signed-off-by: Heyi Guo <guoheyi@linux.alibaba.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
2020-06-10 18:06:45 +00:00

52 lines
1.4 KiB
C

/** @file
* Exception Handling support specific for AArch64
*
* Copyright (c) 2016 HP Development Company, L.P.
*
* SPDX-License-Identifier: BSD-2-Clause-Patent
*
**/
#include <Uefi.h>
#include <Chipset/AArch64.h>
#include <Library/MemoryAllocationLib.h>
#include <Protocol/DebugSupport.h> // for MAX_AARCH64_EXCEPTION
UINTN gMaxExceptionNumber = MAX_AARCH64_EXCEPTION;
EFI_EXCEPTION_CALLBACK gExceptionHandlers[MAX_AARCH64_EXCEPTION + 1] = { 0 };
EFI_EXCEPTION_CALLBACK gDebuggerExceptionHandlers[MAX_AARCH64_EXCEPTION + 1] = { 0 };
PHYSICAL_ADDRESS gExceptionVectorAlignmentMask = ARM_VECTOR_TABLE_ALIGNMENT;
UINTN gDebuggerNoHandlerValue = 0; // todo: define for AArch64
#define EL0_STACK_SIZE EFI_PAGES_TO_SIZE(2)
STATIC UINTN mNewStackBase[EL0_STACK_SIZE / sizeof (UINTN)];
VOID
RegisterEl0Stack (
IN VOID *Stack
);
RETURN_STATUS ArchVectorConfig(
IN UINTN VectorBaseAddress
)
{
UINTN HcrReg;
// Round down sp by 16 bytes alignment
RegisterEl0Stack (
(VOID *)(((UINTN)mNewStackBase + EL0_STACK_SIZE) & ~0xFUL)
);
if (ArmReadCurrentEL() == AARCH64_EL2) {
HcrReg = ArmReadHcr();
// Trap General Exceptions. All exceptions that would be routed to EL1 are routed to EL2
HcrReg |= ARM_HCR_TGE;
ArmWriteHcr(HcrReg);
}
return RETURN_SUCCESS;
}