#include <am.h>
#include <mips32.h>
#include <nemu.h>

#define PG_ALIGN __attribute((aligned(PGSIZE)))

static void* (*pgalloc_usr)(size_t) = NULL;
static void (*pgfree_usr)(void*) = NULL;
static int vme_enable = 0;

int _vme_init(void* (*pgalloc_f)(size_t), void (*pgfree_f)(void*)) {
  pgalloc_usr = pgalloc_f;
  pgfree_usr = pgfree_f;
  vme_enable = 1;

  return 0;
}

int _protect(_AddressSpace *as) {
  as->ptr = (PDE*)(pgalloc_usr(1));

  return 0;
}

void _unprotect(_AddressSpace *as) {
}

static _AddressSpace *cur_as = NULL;
void __am_get_cur_as(_Context *c) {
  c->as = cur_as;
}

void __am_switch(_Context *c) {
  if (vme_enable) {
    cur_as = c->as;
  }
}

int _map(_AddressSpace *as, void *va, void *pa, int prot) {
  return 0;
}

_Context *_ucontext(_AddressSpace *as, _Area ustack, _Area kstack, void *entry, void *args) {
  return NULL;
}