mminit.c

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/*++
 
Module Name:
 
    mminit.c
 
Purpose:
 
    This translation unit contains the implementation of memory manager initialization routines.
 
Author:
 
    slep (Matanel) 2025.
 
Revision History:
 
--*/
 
#include "../../includes/mm.h"
#include "../../includes/me.h"
#include "../../includes/mg.h"
#include "../../assert.h"
 
#define IA32_PAT 0x277
 
static
bool
MiIsPATAvailable(void)
 
{
    uint32_t eax, ebx, ecx, edx;
    __cpuid(1, eax, ebx, ecx, edx);
    return (edx & (1 << 16)) != 0;
}
 
static
void 
MiInitializePAT(void) 
 
{
    uint64_t pat =
        0x00 |                   // 0 = WB
        (0x01ULL << 8) |         // 1 = WT
        (0x02ULL << 16) |        // 2 = UC-
        (0x03ULL << 24) |        // 3 = UC
        (0x00ULL << 32) |        // 4 = WB
        (0x01ULL << 40) |        // 5 = WC
        (0x02ULL << 48) |        // 6 = UC-
        (0x03ULL << 56);         // 7 = UC
 
    __writemsr(IA32_PAT, pat);
}
 
bool
MmInitSystem(
    IN uint8_t Phase,
    IN PBOOT_INFO BootInformation
)
 
/*++
 
    Routine description:
 
        Initializes the memory manager of the system.
 
    Arguments:
 
        [IN]    uint8_t Phase - Specifies the phase of the system for correct init routines. (enum SYSTEM_PHASE_ROUTINE)
        [IN]    PBOOT_INFO BootInformation - The boot information supplied by the UEFI Bootloader (can be NULL in later phases, look below)
 
    Phase Demands:
 
        1 - BootInformation
        2 - None.
 
    Phase Does:
           
        1 (SYSTEM_PHASE_INITIALIZE_ALL) - Initializes PAT and the core memory managment routines. (PFN Database, Virtual Address bitmap, PAT, PTE Database, etc.)
 
        2 (SYSTEM_PHASE_INITIALIZE_PAT_ONLY) - Initializes PAT only (used in AP startup)
 
    Return Values:
 
        True or false if the phase given has succeeded initilization.
 
--*/
 
{
    // Currently we only support the first and only phase.
    if (Phase == SYSTEM_PHASE_INITIALIZE_ALL) {
 
        // Initialize PAT (Page Attribute Table)
        bool PatAvailable = MiIsPATAvailable();
        assert(PatAvailable == true);
        if (PatAvailable) {
            MiInitializePAT();
        }
 
        // Initialize all memory managment routines (PFN Database, VA Space, Pools, MMIO, PTE Database)
        // If we fail init of one of them, we bugcheck, since they are mandatory for operation.
        MTSTATUS st = MiInitializePfnDatabase(BootInformation);
        if (MT_FAILURE(st)) {
            MeBugCheckEx(
                PFN_DATABASE_INIT_FAILURE,
                (void*)(uintptr_t)st,
                NULL,
                NULL,
                NULL
            );
        }
 
        if (!MiInitializePoolVaSpace()) {
            MeBugCheck(VA_SPACE_INIT_FAILURE);
        }
 
        st = MiInitializePoolSystem();
        if (MT_FAILURE(st)) {
            MeBugCheckEx(
                POOL_INIT_FAILURE,
                (void*)(uintptr_t)st,
                NULL,
                NULL,
                NULL
            );
        }
 
        // Phase 1 Done.
        return true;
    }
 
    else if (Phase == SYSTEM_PHASE_INITIALIZE_PAT_ONLY) {
        // Phase only initializes PAT for the current core.
        // Initialize PAT (Page Attribute Table)
        bool PatAvailable = MiIsPATAvailable();
        assert(PatAvailable == true);
        if (PatAvailable) {
            MiInitializePAT();
        }
 
        // Return if PAT is available on the current core or not (if available, it's initialized)
        return PatAvailable;
    }
 
    else {
        // Only phase 1 & 2 are supported currently.
        MeBugCheck(INVALID_INITIALIZATION_PHASE);
    }
}
 
extern GOP_PARAMS gop_local;
extern BOOT_INFO boot_info_local;
 
void
MiMoveUefiDataToHigherHalf(
    IN PBOOT_INFO BootInfo
)
 
 
/*++
 
    Routine description:
 
        Moves UEFI Memory that is mapped below the kernel half to the kernel half.
 
    Arguments:
 
        [IN]    PBOOT_INFO BootInformation - The boot information supplied by the UEFI Bootloader.
 
 
    Return Values:
 
        None.
 
    Notes:
 
        Currently the only UEFI memory that is below the higher half is the GOP. (and RSDP, but that is processed during kernel startup, so its fine)
 
--*/
 
{
    // Move GOP to higher half, luckily i developed this extremely advanced memory api (its just advancing pointers)
    uintptr_t Virt = MiTranslateVirtualToPhysical((void*)gop_local.FrameBufferBase);
 
#ifdef DEBUG
    uint64_t oldBase = gop_local.FrameBufferBase;
#endif
 
    gop_local.FrameBufferBase = (uint64_t)MmMapIoSpace(Virt, gop_local.FrameBufferSize, MmCached);
    assert(gop_local.FrameBufferBase != Virt);
    assert((void*)gop_local.FrameBufferBase != NULL);
 
    // Unmap the previous PTE.
    MiUnmapPte(MiGetPtePointer(Virt));
 
#ifdef DEBUG
    assert(MmIsAddressValid((uintptr_t)oldBase) == false);
#endif
    uintptr_t BootInfoPhys = MiTranslateVirtualToPhysical((void*)BootInfo);
 
    // Destroy the boot_info struct PTE.
    // First, memory set it to 0 (just for good measure)
    kmemset(BootInfo, 0, sizeof(BOOT_INFO));
 
    // Great, unmap it now.
    assert(sizeof(BOOT_INFO) <= VirtualPageSize); // If the size is larger, we would need to do a for loop.
    MiUnmapPte(MiGetPtePointer((uintptr_t)BootInfo));
    assert(MmIsAddressValid((uintptr_t)BootInfo) == false);
 
    // Free its physical frame.
    MiReleasePhysicalPage(PPFN_TO_INDEX(PHYSICAL_TO_PPFN(BootInfoPhys)));
}