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Properly, recursively self map page tables on i686 architecture

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This commit is contained in:
Rafal Kupiec 2024-04-07 17:11:14 +02:00
parent 7c9233c9a2
commit 388ac1a8c2
Signed by: belliash
GPG Key ID: 4E829243E0CFE6B4
2 changed files with 56 additions and 2 deletions
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56
xtldr/arch/i686/memory.c
View File

@ -66,7 +66,7 @@ BlBuildPageMap(IN PXTBL_PAGE_MAPPING PageMap,
}
/* Add page mapping itself to memory mapping */
Status = BlMapVirtualMemory(PageMap, NULL, PageMap->PtePointer, 1, LoaderMemoryData);
Status = BlpSelfMapPml(PageMap, SelfMapAddress);
if(Status != STATUS_EFI_SUCCESS)
{
/* PML mapping failed */
@ -233,3 +233,57 @@ BlMapPage(IN PXTBL_PAGE_MAPPING PageMap,
/* Return success */
return STATUS_EFI_SUCCESS;
}
/**
* Creates a recursive self mapping for all PML levels.
*
* @param PageMap
* Supplies a pointer to the page mapping structure.
*
* @param SelfMapAddress
* Supplies a virtual address of the page tables.
*
* @return This routine returns a status code.
*
* @since XT 1.0
*/
XTCDECL
EFI_STATUS
BlpSelfMapPml(IN PXTBL_PAGE_MAPPING PageMap,
IN ULONG_PTR SelfMapAddress)
{
ULONGLONG PmlIndex;
PHARDWARE_PTE Pml;
ULONG Index;
/* Check page map level */
if(PageMap->PageMapLevel == 3)
{
/* Calculate PML index based on provided self map address */
PmlIndex = (SelfMapAddress >> 21) & 0x1FF;
/* Get Page Directory */
Pml = (PHARDWARE_PTE)(((PHARDWARE_PTE)PageMap->PtePointer)[SelfMapAddress >> 30].PageFrameNumber * EFI_PAGE_SIZE);
/* Add self-mapping for PML3 (PAE enabled) */
for(Index = 0; Index < 4; Index++)
{
Pml[PmlIndex + Index].PageFrameNumber = ((PHARDWARE_PTE)PageMap->PtePointer)[Index].PageFrameNumber;
Pml[PmlIndex + Index].Valid = 1;
Pml[PmlIndex + Index].Writable = 1;
}
}
else
{
/* Calculate PML index based on provided self map address */
PmlIndex = (SelfMapAddress >> 22);
/* Add self-mapping for PML2 (PAE disabled) */
((PHARDWARE_LEGACY_PTE)PageMap->PtePointer)[PmlIndex].PageFrameNumber = (UINT_PTR)PageMap->PtePointer / EFI_PAGE_SIZE;
((PHARDWARE_LEGACY_PTE)PageMap->PtePointer)[PmlIndex].Valid = 1;
((PHARDWARE_LEGACY_PTE)PageMap->PtePointer)[PmlIndex].Writable = 1;
}
/* Return success */
return STATUS_EFI_SUCCESS;
}

2
xtldr/modules/xtos_o/i686/memory.c
View File

@ -55,7 +55,7 @@ XtEnablePaging(IN PXTBL_PAGE_MAPPING PageMap)
}
/* Build page map */
Status = XtLdrProtocol->Memory.BuildPageMap(PageMap, 0);
Status = XtLdrProtocol->Memory.BuildPageMap(PageMap, 0xC0000000);
if(Status != STATUS_EFI_SUCCESS)
{
/* Failed to build page map */