mirror of https://github.com/acidanthera/audk.git
49 lines
1.3 KiB
C
49 lines
1.3 KiB
C
/** @file
|
|
Define the module hooks used while probing the QEMU flash device.
|
|
|
|
Copyright (C) 2018, Advanced Micro Devices. All rights reserved.
|
|
|
|
SPDX-License-Identifier: BSD-2-Clause-Patent
|
|
|
|
**/
|
|
|
|
#include <Library/BaseMemoryLib.h>
|
|
#include <Library/DebugLib.h>
|
|
#include <Library/PcdLib.h>
|
|
#include <Library/MemEncryptSevLib.h>
|
|
|
|
#include "QemuFlash.h"
|
|
|
|
VOID
|
|
QemuFlashBeforeProbe (
|
|
IN EFI_PHYSICAL_ADDRESS BaseAddress,
|
|
IN UINTN FdBlockSize,
|
|
IN UINTN FdBlockCount
|
|
)
|
|
{
|
|
EFI_STATUS Status;
|
|
|
|
ASSERT (FeaturePcdGet (PcdSmmSmramRequire));
|
|
|
|
if (!MemEncryptSevIsEnabled ()) {
|
|
return;
|
|
}
|
|
|
|
//
|
|
// When SEV is enabled, AmdSevDxe runs early in DXE phase and clears the
|
|
// C-bit from the NonExistent entry -- which is later split and accommodate
|
|
// the flash MMIO but the driver runs in non SMM context hence it cleared the
|
|
// flash ranges from non SMM page table. When SMM is enabled, the flash
|
|
// services are accessed from the SMM mode hence we explicitly clear the
|
|
// C-bit on flash ranges from SMM page table.
|
|
//
|
|
|
|
Status = MemEncryptSevClearPageEncMask (
|
|
0,
|
|
BaseAddress,
|
|
EFI_SIZE_TO_PAGES (FdBlockSize * FdBlockCount),
|
|
FALSE
|
|
);
|
|
ASSERT_EFI_ERROR (Status);
|
|
}
|