+++ /dev/null
-#include "vm_flags.h"
-#include <io.h>
-
-#define MAP_FLAGS (PTE_PRESENT | PTE_READ_WRITE)
-
-void * pt_setup(int smbase) {
- int i;
- outb(0x80, 0x51);
-
- /* The page directory and page table live at SMBASE and SMBASE + 0x1000,
- * respectively; clear them. */
- int * pagedirectory = (int *) smbase;
- int * pagetable = (int *) (smbase + 0x1000);
-
- /* Clear out the page directory except for one entry pointing to the
- * page table, and clear the page table entirely. */
- outb(0x80, 0x52);
- pagedirectory[0] = (smbase + 0x1000) | PTE_PRESENT | PTE_READ_WRITE;
- outb(0x80, 0x53);
- for (i = 1; i < 1024; i++)
- {
- pagedirectory[i] = 0;
- }
-
- outb(0x80, 0x54);
- for (i = 0; i < 1024; i++)
- {
- pagetable[i] = 0;
- }
- outb(0x80, 0x55);
-
- /* The page at 0x10000 - 0x10FFF points to the SMI entry point,
- * SMBASE + 0x8000. */
- pagetable[16] = (0x8000 + smbase) | MAP_FLAGS;
-
- /* 0x11000 to 0x1EFFF map to the rest of ASEG up to SMBASE + 0xF000;
- * the page containing the saved state is not mappped to our code
- * region. */
-
- for (i = 0; i < 8; i++)
- {
- pagetable[17 + i] = (i * 0x1000 + smbase) | MAP_FLAGS;
- }
-
- for (i = 0; i < 6; i++)
- {
- pagetable[25 + i] = (smbase + 0x9000 + i * 0x1000) | MAP_FLAGS;
- }
-
- outb(0x80, 0x56);
- /* Map 0xA8000 to itself. */
- pagetable[0xA8] = 0xA8000 | MAP_FLAGS;
- pagetable[0xA9] = 0xA9000 | MAP_FLAGS;
-
- /* No TSEG yet. */
-
- outb(0x80, 0x57);
- return pagedirectory;
-}