Aiken Harris bf291613a3
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Add debug messages to display PML set by bootloader
2025-08-10 18:07:26 +02:00

236 lines
7.4 KiB
C

/**
* PROJECT: ExectOS
* COPYRIGHT: See COPYING.md in the top level directory
* FILE: xtldr/amd64/memory.c
* DESCRIPTION: EFI memory management for AMD64 target
* DEVELOPERS: Rafal Kupiec <belliash@codingworkshop.eu.org>
* Aiken Harris <harraiken91@gmail.com>
*/
#include <xtos.h>
/**
* Determines the appropriate paging level (PML) for the AMD64 architecture.
*
* @param Parameters
* A pointer to the wide character string containing the kernel boot parameters.
*
* @return This routine returns the appropriate page map level (5 if LA57 is enabled, 4 otherwise).
*
* @since XT 1.0
*/
XTCDECL
ULONG
XtpDeterminePagingLevel(IN CONST PWCHAR Parameters)
{
CPUID_REGISTERS CpuRegisters;
/* Prepare CPUID registers to query for STD7 features */
RtlZeroMemory(&CpuRegisters, sizeof(CPUID_REGISTERS));
CpuRegisters.Leaf = CPUID_GET_VENDOR_STRING;
/* Query CPUID */
ArCpuId(&CpuRegisters);
/* Verify if the CPU supports the STD7 feature leaf (0x00000007) */
if(CpuRegisters.Eax >= CPUID_GET_STANDARD7_FEATURES)
{
/* Prepare CPUID registers to query for LA57 support */
RtlZeroMemory(&CpuRegisters, sizeof(CPUID_REGISTERS));
CpuRegisters.Leaf = CPUID_GET_STANDARD7_FEATURES;
/* Query CPUID */
ArCpuId(&CpuRegisters);
/* Check if eXtended Physical Addressing (XPA) is enabled and if LA57 is supported by the CPU */
if((CpuRegisters.Ecx & CPUID_FEATURES_ECX_LA57) &&
!(XtLdrProtocol->BootUtil.GetBooleanParameter(Parameters, L"NOXPA")))
{
/* Enable LA57 (PML5) */
return 5;
}
}
/* Disable LA57 and use PML4 by default */
return 4;
}
/**
* Maps the page table for hardware layer addess space.
*
* @param PageMap
* Supplies a pointer to the page mapping structure.
*
* @return This routine returns a status code.
*
* @since XT 1.0
*/
XTCDECL
EFI_STATUS
XtpMapHardwareMemoryPool(IN PXTBL_PAGE_MAPPING PageMap)
{
PHARDWARE_PTE PdeBase, PpeBase, PxeBase;
EFI_PHYSICAL_ADDRESS Address;
EFI_STATUS Status;
/* Check page map level */
if(PageMap->PageMapLevel > 4)
{
/* PML5 (LA57) is not supported yet */
return STATUS_EFI_UNSUPPORTED;
}
/* Get PXE (PML4) base address */
PxeBase = ((PHARDWARE_PTE)(PageMap->PtePointer));
/* Check if PXE entry already exists */
if(!PxeBase[(MM_HARDWARE_VA_START >> MM_PXI_SHIFT) & 0x1FF].Valid)
{
/* No valid PXE, allocate memory */
Status = XtLdrProtocol->Memory.AllocatePages(1, &Address);
if(Status != STATUS_EFI_SUCCESS)
{
/* Memory allocation failure, return error */
return Status;
}
/* Zero fill memory used by PXE */
RtlZeroMemory((PVOID)Address, EFI_PAGE_SIZE);
/* Make PXE valid */
PxeBase[(MM_HARDWARE_VA_START >> MM_PXI_SHIFT) & 0x1FF].Valid = 1;
PxeBase[(MM_HARDWARE_VA_START >> MM_PXI_SHIFT) & 0x1FF].PageFrameNumber = Address / EFI_PAGE_SIZE;
PxeBase[(MM_HARDWARE_VA_START >> MM_PXI_SHIFT) & 0x1FF].Writable = 1;
/* Set PPE base address */
PpeBase = (PHARDWARE_PTE)(UINT_PTR)Address;
}
else
{
/* Set PPE base address based on existing PXE */
PpeBase = (PHARDWARE_PTE)((PxeBase[(MM_HARDWARE_VA_START >> MM_PXI_SHIFT) & 0x1FF].PageFrameNumber) << EFI_PAGE_SHIFT);
}
/* Check if PPE entry already exists */
if(!PpeBase[(MM_HARDWARE_VA_START >> MM_PPI_SHIFT) & 0x1FF].Valid)
{
/* No valid PPE, allocate memory */
Status = XtLdrProtocol->Memory.AllocatePages(1, &Address);
if(Status != STATUS_EFI_SUCCESS)
{
/* Memory allocation failure, return error */
return Status;
}
/* Zero fill memory used by PPE */
RtlZeroMemory((PVOID)Address, EFI_PAGE_SIZE);
/* Make PPE valid */
PpeBase[(MM_HARDWARE_VA_START >> MM_PPI_SHIFT) & 0x1FF].Valid = 1;
PpeBase[(MM_HARDWARE_VA_START >> MM_PPI_SHIFT) & 0x1FF].PageFrameNumber = Address / EFI_PAGE_SIZE;
PpeBase[(MM_HARDWARE_VA_START >> MM_PPI_SHIFT) & 0x1FF].Writable = 1;
/* Set PDE base address */
PdeBase = (PHARDWARE_PTE)Address;
}
else
{
/* Set PDE base address, based on existing PPE */
PdeBase = (PHARDWARE_PTE)((PpeBase[(MM_HARDWARE_VA_START >> MM_PPI_SHIFT) & 0x1FF].PageFrameNumber) << EFI_PAGE_SHIFT);
}
/* Loop through 2 PDE entries */
for(UINT Index = 0 ; Index < 2 ; Index++)
{
/* Check if PDE entry already exists */
if(!PdeBase[((MM_HARDWARE_VA_START >> MM_PDI_SHIFT) & 0x1FF) + Index].Valid)
{
/* No valid PDE, allocate memory */
Status = XtLdrProtocol->Memory.AllocatePages(1, &Address);
if(Status != STATUS_EFI_SUCCESS)
{
/* Memory allocation failure, return error */
return Status;
}
/* Zero fill memory used by PDE */
RtlZeroMemory((PVOID)Address, EFI_PAGE_SIZE);
/* Make PDE valid */
PdeBase[((MM_HARDWARE_VA_START >> MM_PDI_SHIFT) & 0x1FF) + Index].Valid = 1;
PdeBase[((MM_HARDWARE_VA_START >> MM_PDI_SHIFT) & 0x1FF) + Index].PageFrameNumber = Address / EFI_PAGE_SIZE;
PdeBase[((MM_HARDWARE_VA_START >> MM_PDI_SHIFT) & 0x1FF) + Index].Writable = 1;
}
}
/* Return success */
return STATUS_EFI_SUCCESS;
}
/**
* Builds the actual memory mapping page table and enables paging. This routine exits EFI boot services as well.
*
* @param PageMap
* Supplies a pointer to the page mapping structure.
*
* @return This routine returns a status code.
*
* @since XT 1.0
*/
XTCDECL
EFI_STATUS
XtEnablePaging(IN PXTBL_PAGE_MAPPING PageMap)
{
EFI_STATUS Status;
/* Build page map */
Status = XtLdrProtocol->Memory.BuildPageMap(PageMap, 0xFFFFF6FB7DBED000);
if(Status != STATUS_EFI_SUCCESS)
{
/* Failed to build page map */
XtLdrProtocol->Debug.Print(L"Failed to build page map (Status code: %zX)\n", Status);
return Status;
}
/* Map memory for hardware layer */
Status = XtpMapHardwareMemoryPool(PageMap);
if(Status != STATUS_EFI_SUCCESS)
{
/* Failed to map memory for hardware layer */
XtLdrProtocol->Debug.Print(L"Failed to map memory for hardware leyer (Status code: %zX)\n", Status);
return Status;
}
/* Exit EFI Boot Services */
XtLdrProtocol->Debug.Print(L"Exiting EFI boot services\n");
Status = XtLdrProtocol->Util.ExitBootServices();
if(Status != STATUS_EFI_SUCCESS)
{
/* Failed to exit boot services */
XtLdrProtocol->Debug.Print(L"Failed to exit boot services (Status code: %zX)\n", Status);
return STATUS_EFI_ABORTED;
}
/* Check the configured page map level to set the LA57 state accordingly */
if(PageMap->PageMapLevel == 5)
{
/* Enable Linear Address 57-bit (LA57) extension */
XtLdrProtocol->Debug.Print(L"Enabling Linear Address 57-bit (LA57)\n");
}
else
{
/* Disable Linear Address 57-bit (LA57) extension */
XtLdrProtocol->Debug.Print(L"Disabling Linear Address 57-bit (LA57)\n");
}
/* Write PML4 to CR3 */
ArWriteControlRegister(3, (UINT_PTR)PageMap->PtePointer);
/* Enable paging */
ArWriteControlRegister(0, ArReadControlRegister(0) | CR0_PG);
/* Return success */
return STATUS_EFI_SUCCESS;
}