1 #include <stdio.h>

2 #include "mem.h"

3 #include "panic.h"

4 #include "vm.h"

5

6 /* end of kernel image */

7 extern int _end;

8

9 static uint32_t brk;

10

11 void init_mem(struct mboot_info *mb)

12 {

13 /* start the physical allocated break at the end of

14 * the kernel image

15 */

16 brk = (uint32_t)&_end;

17 }

18

19 uint32_t alloc_phys_page(void)

20 {

21 uint32_t addr, dbg_prev_brk;

22

23 if(ADDR_TO_PGOFFS(brk)) {

24 /* brk is not aligned, find the next page-aligned address */

25 addr = (brk + PGSIZE) & ~PGOFFS_MASK;

26 } else {

27 /* brk is aligned, so we can use that address directly */

28 addr = brk;

29 }

30

31 if(addr >= MAX_BRK) {

32 panic("alloc_phys_page() out of early alloc space");

33 }

34

35 dbg_prev_brk = brk;

36 brk = addr + PGSIZE; /* move the break to the end of the page */

37

38 printf("DBG: alloc_phys_page(): %x (brk %x -> %x)\n", addr, dbg_prev_brk, brk);

39 return addr;

40 }