device: support uartlite

* note that serial input is not supported currently

src/device/device.c

@@ -9,6 +9,7 @@
 
 void init_alarm();
 void init_serial();
+void init_uartlite();
 void init_timer();
 void init_vga();
 void init_i8042();
@@ -56,9 +57,12 @@ void sdl_clear_event_queue() {
 }
 
 void init_device() {
-  init_serial();
+#ifdef XIANGSHAN
+  init_vga();
+  init_uartlite();
+#else
   init_vga();
-#ifndef XIANGSHAN
+  init_serial();
   init_timer();
   init_i8042();
   init_audio();

src/device/uartlite.c

+#include <device/map.h>
+
+#define CH_OFFSET 0
+#define UARTLITE_RX_FIFO  0x0
+#define UARTLITE_TX_FIFO  0x4
+#define UARTLITE_STAT_REG 0x8
+#define UARTLITE_CTRL_REG 0xc
+
+#define UARTLITE_RST_FIFO 0x03
+#define UARTLITE_TX_FULL  0x08
+#define UARTLITE_RX_VALID 0x01
+
+// #define QUEUE_SIZE 1024
+// static char queue[QUEUE_SIZE] = {};
+// static int f = 0, r = 0;
+
+static uint8_t *serial_base = NULL;
+
+// static void serial_enqueue(char ch) {
+//   int next = (r + 1) % QUEUE_SIZE;
+//   if (next != f) {
+//     // not full
+//     queue[r] = ch;
+//     r = next;
+//   }
+// }
+
+// static char serial_dequeue() {
+//   char ch = 0xff;
+
+//   extern uint32_t uptime();
+//   static uint32_t last = 0;
+//   uint32_t now = uptime();
+//   if (now > last) {
+//     Log("now = %d", now);
+//     last = now;
+//   }
+//   // 90s after starting
+//   if (now > 90) {
+//     if (f != r) {
+//       ch = queue[f];
+//       f = (f + 1) % QUEUE_SIZE;
+//     }
+//   }
+//   return ch;
+// }
+
+static void serial_io_handler(uint32_t offset, int len, nemu_bool is_write) {
+  assert(len == 1);
+  switch (offset) {
+    /* We bind the serial port with the host stdout in NEMU. */
+    case UARTLITE_TX_FIFO:
+      if (is_write) putc(serial_base[UARTLITE_TX_FIFO], stderr);
+      else panic("Cannot read UARTLITE_TX_FIFO");
+      break;
+    case UARTLITE_STAT_REG:
+      if (!is_write) serial_base[UARTLITE_STAT_REG] = 0x0;
+      break;
+  }
+}
+
+// #define rt_thread_cmd "memtrace\n"
+// #define busybox_cmd "ls\n" \
+//   "cd /root\n" \
+//   "echo hello2\n" \
+//   "cd /root/benchmark\n" \
+//   "./stream\n" \
+//   "echo hello3\n" \
+//   "cd /root/redis\n" \
+//   "ls\n" \
+//   "ifconfig -a\n" \
+//   "ls\n" \
+//   "./redis-server\n" \
+
+// #define debian_cmd "root\n" \
+
+// static void preset_input() {
+//   char buf[] = debian_cmd;
+//   int i;
+//   for (i = 0; i < strlen(buf); i ++) {
+//     serial_enqueue(buf[i]);
+//   }
+// }
+
+void init_uartlite() {
+  serial_base = new_space(0xd);
+  add_pio_map("uartlite", SERIAL_PORT, serial_base, 0xd, serial_io_handler);
+  add_mmio_map("uartlite", SERIAL_MMIO, serial_base, 0xd, serial_io_handler);
+
+  preset_input();
+}