66 lines
1.5 KiB
C
66 lines
1.5 KiB
C
|
#include <kernel.h>
|
||
|
|
|
||
|
|
#define PAGESIZE (4 * KB)
|
||
|
|
#define PAGEALIGNED __attribute__((__aligned__(4096)))
|
||
|
|
|
||
|
|
// Page directory pointer offset
|
||
|
|
typedef uint pdpe_t;
|
||
|
|
|
||
|
|
// Page directory offset
|
||
|
|
typedef uint pde_t;
|
||
|
|
|
||
|
|
// Page table entry
|
||
|
|
typedef uint pte_t;
|
||
|
|
|
||
|
|
// paging.asm
|
||
|
|
void MmLoadPML4(void *);
|
||
|
|
void MmEnableWriteProtect(void);
|
||
|
|
void MmDisableWriteProtect(void);
|
||
|
|
|
||
|
|
enum
|
||
|
|
{
|
||
|
|
MF_PRESENT = 1 << 0,
|
||
|
|
MF_READWRITE = 1 << 1,
|
||
|
|
MF_USERMODE = 1 << 2,
|
||
|
|
MF_WRITETHR = 1 << 3,
|
||
|
|
MF_CACHEDIS = 1 << 4,
|
||
|
|
MF_ACCESSED = 1 << 5,
|
||
|
|
MF_DIRTY = 1 << 6
|
||
|
|
};
|
||
|
|
|
||
|
|
//-----------
|
||
|
|
|
||
|
|
pdpe_t pml4[1024] ;
|
||
|
|
|
||
|
|
// First PDPE of our pml4
|
||
|
|
pde_t first_pdpe[1024] PAGEALIGNED;
|
||
|
|
|
||
|
|
// First PDP of first_pdpe
|
||
|
|
pte_t first_pde[1024] PAGEALIGNED;
|
||
|
|
|
||
|
|
// First PTE of first_pde
|
||
|
|
uint first_pte[1024] PAGEALIGNED;
|
||
|
|
|
||
|
|
void MmInitPaging(void)
|
||
|
|
{
|
||
|
|
size_t i;
|
||
|
|
|
||
|
|
// Set all PDPEs to kernel-mode not present
|
||
|
|
for (i = 0; i < 1024; i++) pml4[i] = MF_READWRITE;
|
||
|
|
for (i = 0; i < 1024; i++) first_pdpe[i] = MF_READWRITE;
|
||
|
|
for (i = 0; i < 1024; i++) first_pde[i] = MF_READWRITE;
|
||
|
|
|
||
|
|
// Set all pages in first_pte to kernel-mode present
|
||
|
|
for (i = 0; i < 1024; i++) {
|
||
|
|
first_pte[i] = (i * PAGESIZE) | (MF_READWRITE | MF_PRESENT);
|
||
|
|
}
|
||
|
|
|
||
|
|
// Install the first PTE
|
||
|
|
first_pde[0] = (uint)(ulong)first_pte | (MF_READWRITE | MF_PRESENT);
|
||
|
|
first_pdpe[0] = (uint)(ulong)first_pde | (MF_READWRITE | MF_PRESENT);
|
||
|
|
pml4[0] = (uint)(ulong)first_pdpe | (MF_READWRITE | MF_PRESENT);
|
||
|
|
|
||
|
|
MmLoadPML4(pml4);
|
||
|
|
}
|
||
|
|
|