diff --git a/tests/am-tests/Makefile b/tests/am-tests/Makefile
new file mode 100644
index 0000000..907ff4f
--- /dev/null
+++ b/tests/am-tests/Makefile
@@ -0,0 +1,3 @@
+NAME = amtest
+SRCS = $(shell find src/ -name "*.c")
+include $(AM_HOME)/Makefile
diff --git a/tests/am-tests/include/amtest.h b/tests/am-tests/include/amtest.h
new file mode 100644
index 0000000..de172ae
--- /dev/null
+++ b/tests/am-tests/include/amtest.h
@@ -0,0 +1,24 @@
+#ifndef __AMUNIT_H__
+#define __AMUNIT_H__
+
+#include <am.h>
+#include <klib.h>
+#include <klib-macros.h>
+
+#define IOE ({ ioe_init();  })
+#define CTE(h) ({ Context *h(Event, Context *); cte_init(h); })
+#define VME(f1, f2) ({ void *f1(int); void f2(void *); vme_init(f1, f2); })
+#define MPE ({ mpe_init(entry); })
+
+extern void (*entry)();
+
+#define CASE(id, entry_, ...) \
+  case id: { \
+    void entry_(); \
+    entry = entry_; \
+    __VA_ARGS__; \
+    entry_(); \
+    break; \
+  }
+
+#endif
diff --git a/tests/am-tests/src/main.c b/tests/am-tests/src/main.c
new file mode 100644
index 0000000..0c7b300
--- /dev/null
+++ b/tests/am-tests/src/main.c
@@ -0,0 +1,37 @@
+#include <amtest.h>
+
+void (*entry)() = NULL; // mp entry
+
+static const char *tests[256] = {
+  ['h'] = "hello",
+  ['H'] = "display this help message",
+  ['i'] = "interrupt/yield test",
+  ['d'] = "scan devices",
+  ['m'] = "multiprocessor test",
+  ['t'] = "real-time clock test",
+  ['k'] = "readkey test",
+  ['v'] = "display test",
+  ['p'] = "x86 virtual memory test",
+};
+
+int main(const char *args) {
+  switch (args[0]) {
+    CASE('h', hello);
+    CASE('i', hello_intr, IOE, CTE(simple_trap));
+    CASE('d', devscan, IOE);
+    CASE('m', mp_print, MPE);
+    CASE('t', rtc_test, IOE);
+    CASE('k', keyboard_test, IOE);
+    CASE('v', video_test, IOE);
+    CASE('p', vm_test, CTE(vm_handler), VME(simple_pgalloc, simple_pgfree));
+    case 'H':
+    default:
+      printf("Usage: make run mainargs=*\n");
+      for (int ch = 0; ch < 256; ch++) {
+        if (tests[ch]) {
+          printf("  %c: %s\n", ch, tests[ch]);
+        }
+      }
+  }
+  return 0;
+}
diff --git a/tests/am-tests/src/tests/devscan.c b/tests/am-tests/src/tests/devscan.c
new file mode 100644
index 0000000..d2c1a54
--- /dev/null
+++ b/tests/am-tests/src/tests/devscan.c
@@ -0,0 +1,69 @@
+#include <amtest.h>
+
+static void input_test() {
+  printf("Input device test skipped.\n");
+}
+
+static void timer_test() {
+  AM_TIMER_UPTIME_T uptime;
+  uint32_t t0, t1;
+
+  uptime = io_read(AM_TIMER_UPTIME);
+  t0 = uptime.us / 1000;
+
+  for (int volatile i = 0; i < 10000000; i ++) ;
+
+  uptime = io_read(AM_TIMER_UPTIME);
+  t1 = uptime.us / 1000;
+
+  printf("Loop 10^7 time elapse: %d ms\n", t1 - t0);
+}
+
+static uint8_t vmem[512 << 10];
+static inline gpuptr_t to_guest(void *ptr) { return ptr ? (uint8_t *)ptr - vmem : AM_GPU_NULL; }
+
+static void video_test() {
+  AM_GPU_CONFIG_T info = io_read(AM_GPU_CONFIG);
+  int w = info.width, h = info.height;
+  printf("Screen size: %d x %d\n", w, h);
+
+  struct gpu_canvas *cv = (void *)vmem;
+
+  for (uint8_t *p = (void *)&cv[8]; p != vmem + sizeof(vmem); p++)
+    *p = rand() & 0xff;
+
+  cv[0] = (struct gpu_canvas) {
+    .w = -1, .h = -1, .x1 = w / 4, .y1 = 0, .w1 = w / 2, .h1 = h - 100,
+    .type = AM_GPU_TEXTURE,
+    .texture = (struct gpu_texturedesc) {
+      .w = 37, .h = 10,
+      .pixels = to_guest(&cv[8]),
+    },
+    .sibling = to_guest(NULL),
+  };
+
+  io_write(AM_GPU_MEMCPY, 0, vmem, sizeof(vmem));
+  io_write(AM_GPU_RENDER, 0);
+}
+
+static void storage_test() {
+  #define nbytes 512
+  static char buf[nbytes];
+  AM_DISK_CONFIG_T info = io_read(AM_DISK_CONFIG);
+  printf("Storage: %d blocks of %d size. Show first 512 bytes\n", info.blkcnt, info.blksz);
+  io_write(AM_DISK_BLKIO, false, buf, 0, nbytes / info.blksz);
+  for (uint32_t i = 0; i < nbytes; i += 2) {
+    printf("%02x%02x ", buf[i] & 0xff, buf[i+1] & 0xff);
+    if ((i+2) % 32 == 0) printf("\n");
+  }
+}
+
+void devscan() {
+  printf("heap = [%08x, %08x)\n", heap.start, heap.end);
+  input_test();
+  timer_test();
+  video_test();
+  storage_test();
+  printf("Test End!\n");
+  while (1);
+}
diff --git a/tests/am-tests/src/tests/hello.c b/tests/am-tests/src/tests/hello.c
new file mode 100644
index 0000000..7672018
--- /dev/null
+++ b/tests/am-tests/src/tests/hello.c
@@ -0,0 +1,7 @@
+#include <amtest.h>
+
+void hello() {
+  for (int i = 0; i < 10; i ++) {
+    putstr("Hello, AM World @ " __ISA__ "\n");
+  }
+}
diff --git a/tests/am-tests/src/tests/intr.c b/tests/am-tests/src/tests/intr.c
new file mode 100644
index 0000000..e03a0a7
--- /dev/null
+++ b/tests/am-tests/src/tests/intr.c
@@ -0,0 +1,26 @@
+#include <amtest.h>
+
+Context *simple_trap(Event ev, Context *ctx) {
+  switch(ev.event) {
+    case EVENT_IRQ_TIMER:
+      printf("t"); break;
+    case EVENT_IRQ_IODEV:
+      printf("d"); break;
+    case EVENT_YIELD:
+      printf("y"); break;
+    default:
+      break;
+  }
+  return ctx;
+}
+
+void hello_intr() {
+  printf("Hello, AM World @ " __ISA__ "\n");
+  printf("  t = timer, d = device, y = yield\n");
+  io_read(AM_INPUT_CONFIG);
+  iset(1);
+  while (1) {
+    for (volatile int i = 0; i < 10000000; i++) ;
+    yield();
+  }
+}
diff --git a/tests/am-tests/src/tests/keyboard.c b/tests/am-tests/src/tests/keyboard.c
new file mode 100644
index 0000000..3439333
--- /dev/null
+++ b/tests/am-tests/src/tests/keyboard.c
@@ -0,0 +1,35 @@
+#include <amtest.h>
+
+#define NAMEINIT(key)  [ AM_KEY_##key ] = #key,
+static const char *names[] = {
+  AM_KEYS(NAMEINIT)
+};
+
+static bool has_uart, has_kbd;
+
+static void drain_keys() {
+  if (has_uart) {
+    while (1) {
+      char ch = io_read(AM_UART_RX).data;
+      if (ch == -1) break;
+      printf("Got (uart): %c (%d)\n", ch, ch & 0xff);
+    }
+  }
+
+  if (has_kbd) {
+    while (1) {
+      AM_INPUT_KEYBRD_T ev = io_read(AM_INPUT_KEYBRD);
+      if (ev.keycode == AM_KEY_NONE) break;
+      printf("Got  (kbd): %s (%d) %s\n", names[ev.keycode], ev.keycode, ev.keydown ? "DOWN" : "UP");
+    }
+  }
+}
+
+void keyboard_test() {
+  printf("Try to press any key (uart or keyboard)...\n");
+  has_uart = io_read(AM_UART_CONFIG).present;
+  has_kbd  = io_read(AM_INPUT_CONFIG).present;
+  while (1) {
+    drain_keys();
+  }
+}
diff --git a/tests/am-tests/src/tests/mp.c b/tests/am-tests/src/tests/mp.c
new file mode 100644
index 0000000..787de79
--- /dev/null
+++ b/tests/am-tests/src/tests/mp.c
@@ -0,0 +1,7 @@
+#include <amtest.h>
+
+void mp_print() {
+  while (1) {
+    printf("%d", cpu_current());
+  }
+}
diff --git a/tests/am-tests/src/tests/rtc.c b/tests/am-tests/src/tests/rtc.c
new file mode 100644
index 0000000..5db6f74
--- /dev/null
+++ b/tests/am-tests/src/tests/rtc.c
@@ -0,0 +1,17 @@
+#include <amtest.h>
+
+void rtc_test() {
+  AM_TIMER_RTC_T rtc;
+  int sec = 1;
+  while (1) {
+    while(io_read(AM_TIMER_UPTIME).us / 1000000 < sec) ;
+    rtc = io_read(AM_TIMER_RTC);
+    printf("%d-%d-%d %02d:%02d:%02d GMT (", rtc.year, rtc.month, rtc.day, rtc.hour, rtc.minute, rtc.second);
+    if (sec == 1) {
+      printf("%d second).\n", sec);
+    } else {
+      printf("%d seconds).\n", sec);
+    }
+    sec ++;
+  }
+}
diff --git a/tests/am-tests/src/tests/video.c b/tests/am-tests/src/tests/video.c
new file mode 100644
index 0000000..21b4d72
--- /dev/null
+++ b/tests/am-tests/src/tests/video.c
@@ -0,0 +1,90 @@
+#include <amtest.h>
+
+#define FPS 30
+#define N   32
+
+static inline uint32_t pixel(uint8_t r, uint8_t g, uint8_t b) {
+  return (r << 16) | (g << 8) | b;
+}
+static inline uint8_t R(uint32_t p) { return p >> 16; }
+static inline uint8_t G(uint32_t p) { return p >> 8; }
+static inline uint8_t B(uint32_t p) { return p; }
+
+static uint32_t canvas[N][N];
+static int used[N][N];
+
+static uint32_t color_buf[32 * 32];
+
+void redraw() {
+  int w = io_read(AM_GPU_CONFIG).width / N;
+  int h = io_read(AM_GPU_CONFIG).height / N;
+  int block_size = w * h;
+  assert((uint32_t)block_size <= LENGTH(color_buf));
+
+  int x, y, k;
+  for (y = 0; y < N; y ++) {
+    for (x = 0; x < N; x ++) {
+      for (k = 0; k < block_size; k ++) {
+        color_buf[k] = canvas[y][x];
+      }
+      io_write(AM_GPU_FBDRAW, x * w, y * h, color_buf, w, h, false);
+    }
+  }
+  io_write(AM_GPU_FBDRAW, 0, 0, NULL, 0, 0, true);
+}
+
+static uint32_t p(int tsc) {
+  int b = tsc & 0xff;
+  return pixel(b * 6, b * 7, b);
+}
+
+void update() {
+  static int tsc = 0;
+  static int dx[4] = {0, 1, 0, -1};
+  static int dy[4] = {1, 0, -1, 0};
+
+  tsc ++;
+
+  for (int i = 0; i < N; i ++)
+    for (int j = 0; j < N; j ++) {
+      used[i][j] = 0;
+    }
+
+  int init = tsc * 1;
+  canvas[0][0] = p(init); used[0][0] = 1;
+  int x = 0, y = 0, d = 0;
+  for (int step = 1; step < N * N; step ++) {
+    for (int t = 0; t < 4; t ++) {
+      int x1 = x + dx[d], y1 = y + dy[d];
+      if (x1 >= 0 && x1 < N && y1 >= 0 && y1 < N && !used[x1][y1]) {
+        x = x1; y = y1;
+        used[x][y] = 1;
+        canvas[x][y] = p(init + step / 2);
+        break;
+      }
+      d = (d + 1) % 4;
+    }
+  }
+}
+
+void video_test() {
+  unsigned long last = 0;
+  unsigned long fps_last = 0;
+  int fps = 0;
+
+  while (1) {
+    unsigned long upt = io_read(AM_TIMER_UPTIME).us / 1000;
+    if (upt - last > 1000 / FPS) {
+      update();
+      redraw();
+      last = upt;
+      fps ++;
+    }
+    if (upt - fps_last > 1000) {
+      // display fps every 1s
+      printf("%d: FPS = %d\n", upt, fps);
+      fps_last = upt;
+      fps = 0;
+    }
+  }
+}
diff --git a/tests/am-tests/src/tests/vm.c b/tests/am-tests/src/tests/vm.c
new file mode 100644
index 0000000..c89079f
--- /dev/null
+++ b/tests/am-tests/src/tests/vm.c
@@ -0,0 +1,90 @@
+#include <amtest.h>
+
+static Context *uctx;
+static AddrSpace prot;
+static uintptr_t st = 0;
+static int first_trap = 1;
+
+void *simple_pgalloc(int size) {
+  if (st == 0) { st = (uintptr_t)heap.start; }
+  while (st % size != 0) st++;
+  void *ret = (void *)st;
+  st += size;
+  return ret;
+}
+
+void simple_pgfree(void *ptr) {
+}
+
+Context* vm_handler(Event ev, Context *ctx) {
+  switch (ev.event) {
+    case EVENT_YIELD:
+      break;
+    case EVENT_IRQ_TIMER:
+    case EVENT_IRQ_IODEV:
+      printf("==== interrupt (%s)  ====\n", ev.msg);
+      break;
+    case EVENT_PAGEFAULT:
+      printf("PF: %x %s%s%s\n",
+        ev.ref,
+        (ev.cause & MMAP_NONE)  ? "[not present]" : "",
+        (ev.cause & MMAP_READ)  ? "[read fail]"   : "",
+        (ev.cause & MMAP_WRITE) ? "[write fail]"  : "");
+      break;
+    case EVENT_SYSCALL:
+      iset(1);
+      for (int volatile i = 0; i < 1000000; i++) ;
+      printf("%d ", ctx->GPRx);
+      break;
+    default:
+      assert(0);
+  }
+  if (first_trap) {
+    first_trap = 0;
+    return uctx;
+  } else {
+    return ctx;
+  }
+}
+
+uint8_t code[] = {
+#ifdef __ARCH_NATIVE
+  0x31, 0xc0,             // xor %eax, %eax
+  0x83, 0xc0, 0x01,       // add $1, %eax
+  0xff, 0x14, 0x25, 0x00, 0x00, 0x10, 0x00, // call *0x100000
+  0xeb, 0xf4,             // jmp 2
+#else
+  0x31, 0xc0,             // xor %eax, %eax
+  0x8d, 0xb6,             // lea 0(%esi), %esi
+  0x00, 0x00, 0x00, 0x00,
+  0x83, 0xc0, 0x01,       // add $1, %eax
+  0xcd, 0x80,             // int $0x80
+  0xeb, 0xf9,             // jmp 8
+#endif
+
+};
+
+void vm_test() {
+  if (!strncmp(__ISA__, "x86", 3) == 0 &&
+      !strcmp(__ISA__, "native") == 0) {
+    printf("Not supported architecture.\n");
+    return;
+  }
+  protect(&prot);
+  printf("Protected address space: [%p, %p)\n", prot.area.start, prot.area.end);
+
+  uint8_t *ptr = (void*)((uintptr_t)(prot.area.start) +
+     ((uintptr_t)(prot.area.end) - (uintptr_t)(prot.area.start)) / 2);
+
+  void *pg = simple_pgalloc(prot.pgsize);
+  memcpy(pg, code, sizeof(code));
+
+  map(&prot, ptr, pg, MMAP_WRITE | MMAP_READ);
+  printf("Code copied to %p (physical %p) execute\n", ptr, pg);
+
+  static uint8_t stack[4096];
+  uctx = ucontext(&prot, RANGE(stack, stack + sizeof(stack)), ptr);
+
+  iset(1);
+  yield();
+}