Files
system76-edk2/MdeModulePkg/Core/DxeIplPeim/DxeHandoff.c
Ard Biesheuvel 9df2c0a555 MdeModulePkg/DxeIpl: Use memory attribute PPI to remap the stack NX
If the associated PCD is set to TRUE, use the memory attribute PPI to
remap the stack non-executable. This provides a generic method for doing
so, which will be used by ARM and AArch64 as well once they move to the
generic DxeIpl handoff implementation.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Oliver Smith-Denny <osde@linux.microsoft.com>
Reviewed-by: Michael Kubacki <michael.kubacki@microsoft.com>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>
2023-06-26 09:11:53 +00:00

89 lines
2.5 KiB
C

/** @file
Generic version of arch-specific functionality for DxeLoad.
Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2023, Google, LLC. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include "DxeIpl.h"
#include <Ppi/MemoryAttribute.h>
/**
Transfers control to DxeCore.
This function performs a CPU architecture specific operations to execute
the entry point of DxeCore with the parameters of HobList.
It also installs EFI_END_OF_PEI_PPI to signal the end of PEI phase.
@param DxeCoreEntryPoint The entry point of DxeCore.
@param HobList The start of HobList passed to DxeCore.
**/
VOID
HandOffToDxeCore (
IN EFI_PHYSICAL_ADDRESS DxeCoreEntryPoint,
IN EFI_PEI_HOB_POINTERS HobList
)
{
VOID *BaseOfStack;
VOID *TopOfStack;
EFI_STATUS Status;
EDKII_MEMORY_ATTRIBUTE_PPI *MemoryPpi;
//
// Allocate 128KB for the Stack
//
BaseOfStack = AllocatePages (EFI_SIZE_TO_PAGES (STACK_SIZE));
ASSERT (BaseOfStack != NULL);
if (PcdGetBool (PcdSetNxForStack)) {
Status = PeiServicesLocatePpi (
&gEdkiiMemoryAttributePpiGuid,
0,
NULL,
(VOID **)&MemoryPpi
);
ASSERT_EFI_ERROR (Status);
Status = MemoryPpi->SetPermissions (
MemoryPpi,
(UINTN)BaseOfStack,
STACK_SIZE,
EFI_MEMORY_XP,
EFI_MEMORY_XP
);
ASSERT_EFI_ERROR (Status);
}
//
// Compute the top of the stack we were allocated. Pre-allocate a UINTN
// for safety.
//
TopOfStack = (VOID *)((UINTN)BaseOfStack + EFI_SIZE_TO_PAGES (STACK_SIZE) * EFI_PAGE_SIZE - CPU_STACK_ALIGNMENT);
TopOfStack = ALIGN_POINTER (TopOfStack, CPU_STACK_ALIGNMENT);
//
// End of PEI phase signal
//
Status = PeiServicesInstallPpi (&gEndOfPeiSignalPpi);
ASSERT_EFI_ERROR (Status);
//
// Update the contents of BSP stack HOB to reflect the real stack info passed to DxeCore.
//
UpdateStackHob ((EFI_PHYSICAL_ADDRESS)(UINTN)BaseOfStack, STACK_SIZE);
//
// Transfer the control to the entry point of DxeCore.
//
SwitchStack (
(SWITCH_STACK_ENTRY_POINT)(UINTN)DxeCoreEntryPoint,
HobList.Raw,
NULL,
TopOfStack
);
}