> compile NEMU

221220000 张三
Linux zzy 5.15.146.1-microsoft-standard-WSL2 #1 SMP Thu Jan 11 04:09:03 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux
 20:49:41 up 3 days, 15:55,  1 user,  load average: 0.79, 0.71, 0.56

nemu/src/device/audio.c

@@ -29,27 +29,74 @@ enum {
 
 static uint8_t *sbuf = NULL;
 static uint32_t *audio_base = NULL;
+static uint32_t pos_read = 0;
 
-// static void init_sdl_audio() {
-//   SDL_AudioSpec s = {};
-//   s.format = AUDIO_S16SYS;  // 假设系统中音频数据的格式总是使用16位有符号数来表示
-//   s.userdata = NULL;        // 不使用
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
 
-//   SDL_InitSubSystem(SDL_INIT_AUDIO);
-//   SDL_OpenAudio(&s, NULL);
-//   SDL_PauseAudio(0);
-// }
+static void audio_callback(void *userdata, uint8_t *stream, int len) {
+  uint32_t count = audio_base[reg_count];
+  uint32_t read_cnt = MIN(count, len);
+  uint32_t to_end_cnt = audio_base[reg_sbuf_size] - pos_read;
+  int32_t out_bound_cnt = read_cnt - to_end_cnt;
+  if (out_bound_cnt > 0) {
+    SDL_memcpy(stream, sbuf + pos_read, to_end_cnt);
+    SDL_memcpy(stream + to_end_cnt, sbuf, out_bound_cnt);
+  } else {
+    SDL_memcpy(stream, sbuf + pos_read, read_cnt);
+  }
+  pos_read += read_cnt;
+  pos_read %= audio_base[reg_sbuf_size];
+  if (len > read_cnt) SDL_memset(stream + read_cnt, 0, len - read_cnt);
+  audio_base[reg_count] -= read_cnt;
+}
+
+static inline void init_audio_dev() {
+  SDL_AudioSpec s = {};
+  s.format = AUDIO_S16SYS;  // 假设系统中音频数据的格式总是使用16位有符号数来表示
+  s.userdata = NULL;        // 不使用
+  s.freq = audio_base[reg_freq];
+  s.channels = audio_base[reg_channels];
+  s.samples = audio_base[reg_samples];
+  s.callback = audio_callback;
+  
+  assert(SDL_InitSubSystem(SDL_INIT_AUDIO) == 0);
+  assert(SDL_OpenAudio(&s, NULL) == 0);
+  SDL_PauseAudio(0);
+}
 
 static void audio_io_handler(uint32_t offset, int len, bool is_write) {
-
+  assert(offset % 4 == 0);
+  int idx = offset / 4;
+  switch (idx) {
+    case reg_freq:
+    case reg_channels:
+    case reg_samples:
+      break;
+    case reg_sbuf_size:
+      assert(is_write == false);
+      break;
+    case reg_init:
+      if (is_write && audio_base[reg_init] != 0) {
+        init_audio_dev();
+      }
+      break;
+    case reg_count:
+      // TODO: must be add a lock here
+      break;
+    default:
+      assert(0);
+  }
 }
 
 void init_audio() {
-  audio_base = (uint32_t *)new_space(24);
+  uint32_t space_size = sizeof(uint32_t) * nr_reg;
+  audio_base = (uint32_t *)new_space(space_size);
+  audio_base[reg_sbuf_size] = CONFIG_SB_SIZE;
+  audio_base[reg_init] = 0;
 #ifdef CONFIG_HAS_PORT_IO
-  add_pio_map ("audio", CONFIG_AUDIO_CTL_PORT, audio_base, 24, audio_io_handler);
+  add_pio_map ("audio", CONFIG_AUDIO_CTL_PORT, audio_base, space_size, audio_io_handler);
 #else
-  add_mmio_map("audio", CONFIG_AUDIO_CTL_MMIO, audio_base, 24, audio_io_handler);
+  add_mmio_map("audio", CONFIG_AUDIO_CTL_MMIO, audio_base, space_size, audio_io_handler);
 #endif
 
   sbuf = (uint8_t *)new_space(CONFIG_SB_SIZE);

nemu/src/device/vga.c

@@ -84,6 +84,7 @@ void vga_update_screen() {
 void init_vga() {
   vgactl_port_base = (uint32_t *)new_space(8);
   vgactl_port_base[0] = (screen_width() << 16) | screen_height();
+  vgactl_port_base[1] = 0;
 #ifdef CONFIG_HAS_PORT_IO
   add_pio_map ("vgactl", CONFIG_VGA_CTL_PORT, vgactl_port_base, 8, NULL);
 #else