Merge branch 'rt-thread' into 'rv64'

Rt thread

See merge request projectn/nemu!13

src/device/serial.c

@@ -7,20 +7,51 @@
 #define SERIAL_MMIO 0xa10003F8
 #define CH_OFFSET 0
 
+#define QUEUE_SIZE 1024
+static char queue[QUEUE_SIZE] = {};
+static int f = 0, r = 0;
+
 static uint8_t *serial_ch_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 void serial_ch_io_handler(uint32_t offset, int len, bool is_write) {
   assert(offset == 0);
-  assert(is_write);
   assert(len == 1);
 
-  char c = serial_ch_base[0];
-  /* We bind the serial port with the host stdout in NEMU. */
-  putc(c, stderr);
+  if (is_write) {
+    char c = serial_ch_base[0];
+    /* We bind the serial port with the host stdout in NEMU. */
+    putc(c, stderr);
+  } else {
+    if (f != r) {
+      serial_ch_base[0] = queue[f];
+      f = (f + 1) % QUEUE_SIZE;
+    } else {
+      serial_ch_base[0] = 0xff;
+    }
+  }
+}
+
+static void preset_input() {
+  char buf[128] = "memtrace\n";
+  int i;
+  for (i = 0; i < strlen(buf); i ++) {
+    serial_enqueue(buf[i]);
+  }
 }
 
 void init_serial() {
   serial_ch_base = new_space(1);
   add_pio_map("serial", SERIAL_PORT + CH_OFFSET, serial_ch_base, 1, serial_ch_io_handler);
   add_mmio_map("serial", SERIAL_MMIO + CH_OFFSET, serial_ch_base, 1, serial_ch_io_handler);
+
+  preset_input();
 }

src/isa/riscv64/csr.h

@@ -5,7 +5,7 @@
 
 #define CSRS(f) \
   f(mstatus    , 0x300) f(mtvec      , 0x305) f(mepc       , 0x341) f(mcause     , 0x342)  \
-  f(mie        , 0x304) f(satp       , 0x180)
+  f(mie        , 0x304) f(mhartid    , 0xf14) f(satp       , 0x180)
 
 #define CSR_STRUCT_START(name) \
   typedef union { \
@@ -45,6 +45,9 @@ CSR_STRUCT_END(mcause)
 CSR_STRUCT_START(mepc)
 CSR_STRUCT_END(mepc)
 
+CSR_STRUCT_START(mhartid)
+CSR_STRUCT_END(mhartid)
+
 CSR_STRUCT_START(mie)
   uint64_t usie : 1;
   uint64_t ssie : 1;