friend042.cc

#include "app.h"
#include "common.h"

void show_i(F2H &f2h, int i) {
  char mes[] = "i=0";
  mes[2] += i;
  puts(f2h, mes);
}
/*どの程度メモリが使用されているかを検知することができればメモリ管理ができるのでは？
 参考: Ingensでは100%(2MB)以外ヒュージページ化していない
 つまり、0xC0000000もしくは0xC0200000からの2MBが使用されていたらヒュージページ化するということ？
 例: pd2[1] = pd2[1] | (1 << 7);
 */

void create_pagetable(uint64_t *page_structures, uint64_t *pd_for_baremetal,
                      uint64_t page_for_app) {
  // how to use 16KB
  // 0-4KB: PML4T
  // 4KB-8KB: PDPT
  // 8KB-12KB: PD
  // 12KB-16KB: PT
  uint64_t *pml4t = page_structures;
  uint64_t *pdpt = (uint64_t *)((uint64_t)page_structures + 0x1000);
  uint64_t *pd = (uint64_t *)((uint64_t)page_structures + 0x2000);
  uint64_t *pt = (uint64_t *)((uint64_t)page_structures + 0x3000);

  pml4t[0] = ((uint64_t)pdpt + 0x80000000UL) | (1 << 0) | (1 << 1) | (1 << 2);
  pdpt[0] = ((uint64_t)pd_for_baremetal + 0x80000000UL) | (1 << 0) | (1 << 1) |
            (1 << 2);
  pdpt[3] = ((uint64_t)pd + 0x80000000UL) | (1 << 0) | (1 << 1) | (1 << 2);
  pd[0] = ((uint64_t)pt + 0x80000000UL) | (1 << 0) | (1 << 1) | (1 << 2);
  pt[0] = page_for_app | (1 << 0) | (1 << 1) | (1 << 2);
}

void map_page(uint64_t *page_structures) {
  uint64_t *pt = (uint64_t *)((uint64_t)page_structures + 0x3000);
  pt[1] = 0x80700000UL | (1 << 0) | (1 << 1) | (1 << 2);
  asm volatile("invlpg (%0)" ::"b"(0xC0000000UL) : "memory");
}

void unmap_page(uint64_t *page_structures) {
  uint64_t *pt = (uint64_t *)((uint64_t)page_structures + 0x3000);
  pt[1] = 0;
  asm volatile("invlpg (%0)" ::"b"(0xC0000000UL) : "memory");
}

int main() {
  F2H f2h;

  puts(f2h, "hello!");

  memset((void *)0x310000UL, 0, 0x9000);

  uint64_t *page_structures_for_app1 =
      (uint64_t *)0x310000UL;  // 16KB (for PML4T, PDPT, PD, PT)
  uint64_t *page_structures_for_app2 =
      (uint64_t *)0x314000UL;  // 16KB (for PML4T, PDPT, PD, PT)
  uint64_t *pd_for_baremetal = (uint64_t *)0x318000UL;

  // page directory of virtual address 0 - 1GB (for friend.cc)
  // shared by app1 and app2
  for (int i = 0; i < 512; i++) {
    pd_for_baremetal[i] = (0x80000000UL + 0x200000UL * i) | (1 << 0) |
                          (1 << 1) | (1 << 2) | (1 << 7) | (1 << 8);
  }

  create_pagetable(page_structures_for_app1, pd_for_baremetal, 0x80500000UL);
  create_pagetable(page_structures_for_app2, pd_for_baremetal, 0x80600000UL);
  uint64_t *pml4t_for_app1 = page_structures_for_app1;
  uint64_t *pml4t_for_app2 = page_structures_for_app2;

  extern uint8_t _binary_app1_start[];
  extern uint8_t _binary_app1_size[];
  extern uint8_t _binary_app2_start[];
  extern uint8_t _binary_app2_size[];
  memcpy((void *)0x500000UL, (const void *)_binary_app1_start,
         (size_t)_binary_app1_size);
  memcpy((void *)0x600000UL, (const void *)_binary_app2_start,
         (size_t)_binary_app2_size);

  Context c1;
  c1.next = (Context(*)(Context))0xC0000000UL;  // entry1
  c1.i = 0;

  asm volatile("movq %0, %%cr3" ::"r"((uint64_t)pml4t_for_app1 + 0x80000000UL));
  map_page(page_structures_for_app1);
  c1 = c1.next(c1);  // call entry1
  unmap_page(page_structures_for_app1);

  show_i(f2h, c1.i);

  if (c1.i != 1) {
    return_value(f2h, 1);
    return 1;
  }

  Context c2;
  c2.next = (Context(*)(Context))0xC0000000UL;  // entry3
  c2.i = 0;

  asm volatile("movq %0, %%cr3" ::"r"((uint64_t)pml4t_for_app2 + 0x80000000UL));
  c2 = c2.next(c2);  // call entry3

  show_i(f2h, c2.i);

  if (c2.i != 9) {
    return_value(f2h, 1);
    return 1;
  }

  asm volatile("movq %0, %%cr3" ::"r"((uint64_t)pml4t_for_app1 + 0x80000000UL));
  c1 = c1.next(c1);  // call entry2

  show_i(f2h, c1.i);

  if (c1.i != 2) {
    return_value(f2h, 1);
    return 1;
  }

  asm volatile("movq %0, %%cr3" ::"r"((uint64_t)pml4t_for_app2 + 0x80000000UL));
  map_page(page_structures_for_app2);
  c2 = c2.next(c2);  // call entry4
  unmap_page(page_structures_for_app2);

  show_i(f2h, c2.i);

  if (c2.i != 8) {
    return_value(f2h, 1);
    return 1;
  }

  puts(f2h, "bye!");

  return_value(f2h, 0);

  return 0;
}