1.1 --- a/src/vm.c	Sat Mar 26 21:39:14 2011 +0200
     1.2 +++ b/src/vm.c	Sun Mar 27 06:28:26 2011 +0300
     1.3 @@ -16,7 +16,7 @@
     1.4  static void pgfault(int inum, uint32_t err);
     1.5  
     1.6  /* page directory */
     1.7 -static uint32_t pgdir[1024];
     1.8 +static uint32_t *pgdir;
     1.9  
    1.10  #define KMEM_START		0xc0000000
    1.11  #define IDMAP_START		0xa0000
    1.12 @@ -31,6 +31,7 @@
    1.13  {
    1.14  	init_mem(mb);
    1.15  
    1.16 +	pgdir = (uint32_t*)alloc_phys_page();
    1.17  	memset(pgdir, 0, sizeof pgdir);
    1.18  
    1.19  	/* map the video memory and kernel code 1-1 */
    1.20 @@ -51,6 +52,8 @@
    1.21  	if(!(pgdir[diridx] & PG_PRESENT)) {
    1.22  		uint32_t addr = alloc_phys_page();
    1.23  		pgtbl = (uint32_t*)addr;
    1.24 +		memset(pgtbl, 0, PGSIZE);
    1.25 +
    1.26  		pgdir[diridx] = addr | (attr & ATTR_PGDIR_MASK) | PG_PRESENT;
    1.27  	} else {
    1.28  		pgtbl = (uint32_t*)(pgdir[diridx] & ADDR_PGENT_MASK);
    1.29 @@ -128,6 +131,25 @@
    1.30  	}
    1.31  */
    1.32  
    1.33 +uint32_t virt_to_phys(uint32_t vaddr)
    1.34 +{
    1.35 +	uint32_t pgaddr, *pgtbl;
    1.36 +	int diridx = ADDR_TO_PGTBL(vaddr);
    1.37 +	int pgidx = ADDR_TO_PGTBL_PG(vaddr);
    1.38 +
    1.39 +	if(!(pgdir[diridx] & PG_PRESENT)) {
    1.40 +		panic("virt_to_phys(%x): page table %d not present\n", vaddr, diridx);
    1.41 +	}
    1.42 +	pgtbl = (uint32_t*)(pgdir[diridx] & PGENT_ADDR_MASK);
    1.43 +
    1.44 +	if(!(pgtbl[pgidx] & PG_PRESENT)) {
    1.45 +		panic("virt_to_phys(%x): page %d not present\n", vaddr, ADDR_TO_PAGE(vaddr));
    1.46 +	}
    1.47 +	pgaddr = pgtbl[pgidx] & PGENT_ADDR_MASK;
    1.48 +
    1.49 +	return pgaddr | ADDR_TO_PGOFFS(vaddr);
    1.50 +}
    1.51 +
    1.52  static void pgfault(int inum, uint32_t err)
    1.53  {
    1.54  	printf("~~~~ PAGE FAULT ~~~~\n");

     2.1 --- a/src/vm.h	Sat Mar 26 21:39:14 2011 +0200
     2.2 +++ b/src/vm.h	Sun Mar 27 06:28:26 2011 +0300
     2.3 @@ -20,6 +20,7 @@
     2.4  #define PGSIZE					4096
     2.5  #define PGOFFS_MASK				0xfff
     2.6  #define PGNUM_MASK				0xfffff000
     2.7 +#define PGENT_ADDR_MASK			PGNUM_MASK
     2.8  
     2.9  #define ADDR_TO_PAGE(x)		((uint32_t)(x) >> 12)
    2.10  #define PAGE_TO_ADDR(x)		((uint32_t)(x) << 12)
    2.11 @@ -39,4 +40,6 @@
    2.12  
    2.13  void map_mem_range(uint32_t vaddr, size_t sz, uint32_t paddr, unsigned int attr);
    2.14  
    2.15 +uint32_t virt_to_phys(uint32_t vaddr);
    2.16 +
    2.17  #endif	/* VM_H_ */