update string.h and add virtio_tester()

08-BlockDeviceDriver/os.c

@@ -24,12 +24,12 @@ void os_start()
 	trap_init();
 	plic_init();
 	timer_init(); // start timer interrupt ...
+	virtio_tester();
 }
 
 int os_main(void)
 {
 	os_start();
-
 	int current_task = 0;
 	while (1)
 	{

08-BlockDeviceDriver/string.c

@@ -9,4 +9,32 @@ void *memset(void *dst, int c, unsigned int n)
     cdst[i] = c;
   }
   return dst;
+}
+
+void *
+memcpy(void *dst, const void *src, unsigned int n)
+{
+  return memmove(dst, src, n);
+}
+
+void *
+memmove(void *dst, const void *src, unsigned int n)
+{
+  const char *s;
+  char *d;
+
+  s = src;
+  d = dst;
+  if (s < d && s + n > d)
+  {
+    s += n;
+    d += n;
+    while (n-- > 0)
+      *--d = *--s;
+  }
+  else
+    while (n-- > 0)
+      *d++ = *s++;
+
+  return dst;
 }

08-BlockDeviceDriver/string.h

@@ -2,5 +2,9 @@
 #define __STRING_H__
 
 void *memset(void *, int, unsigned int);
+void *
+memcpy(void *dst, const void *src, unsigned int n);
+void *
+memmove(void *dst, const void *src, unsigned int n);
 
 #endif

08-BlockDeviceDriver/user.c

@@ -53,11 +53,13 @@ void user_task3(void)
 	}
 }
 
+extern virtio_tester();
+
 void user_init()
 {
-	lock_init(&lock);
+	// lock_init(&lock);
 	task_create(&user_task0);
 	task_create(&user_task1);
-	task_create(&user_task2);
+	// task_create(&user_task2);
-	task_create(&user_task3);
+	// task_create(&user_task3);
 }

08-BlockDeviceDriver/virtio.c

@@ -18,6 +18,17 @@ struct buf
   unsigned char data[BSIZE];
 };
 
+struct
+{
+  lock_t lock;
+  struct buf buf[30];
+
+  // Linked list of all buffers, through prev/next.
+  // Sorted by how recently the buffer was used.
+  // head.next is most recent, head.prev is least.
+  struct buf head;
+} bcache;
+
 static struct disk
 {
   char pages[2 * PGSIZE];
@@ -41,6 +52,40 @@ static struct disk
   struct lock vdisk_lock;
 } __attribute__((aligned(PGSIZE))) disk;
 
+void virtio_tester()
+{
+  // int valid; // has data been read from disk?
+  // int disk;  // does disk "own" buf?
+  // uint32 dev;
+  // uint32 blockno;
+  // lock_t lock;
+  // uint32 refcnt;
+  // struct buf *prev; // LRU cache list
+  // struct buf *next;
+  // unsigned char data[BSIZE];
+  struct buf b[3];
+  lib_puts("buffer init...\n");
+  for (size_t i = 0; i < 3; i++)
+  {
+    b[i].valid = 1;
+    b[i].disk = 1;
+    b[i].dev = 1;
+    b[i].blockno = i;
+    for (size_t j = 0; j < BSIZE; j++)
+    {
+      b[i].data[j] = (j + i + 1) % 10;
+    }
+
+    lock_init(&(b[i].lock));
+  }
+  lib_puts("buffer write...\n");
+  for (size_t i = 0; i < 3; i++)
+  {
+    virtio_disk_rw(&b[i], 1);
+  }
+  lib_puts("wait...\n");
+}
+
 void virtio_disk_init()
 {
   uint32 status = 0;
@@ -180,6 +225,7 @@ void virtio_disk_rw(struct buf *b, int write)
   // data, one for a 1-byte status result.
 
   // allocate the three descriptors.
+  lib_puts("rw init...\n");
   int idx[3];
   while (1)
   {
@@ -227,7 +273,7 @@ void virtio_disk_rw(struct buf *b, int write)
 
   // tell the device the first index in our chain of descriptors.
   disk.avail->ring[disk.avail->idx % NUM] = idx[0];
-
+  lib_puts("rw wait...\n");
   __sync_synchronize();
 
   // tell the device another avail ring entry is available.
@@ -238,9 +284,9 @@ void virtio_disk_rw(struct buf *b, int write)
   *R(VIRTIO_MMIO_QUEUE_NOTIFY) = 0; // value is queue number
 
   // Wait for virtio_disk_intr() to say request has finished.
-  while (b->disk == 1)
+  // while (b->disk == 1)
-  {
+  // {
-  }
+  // }
 
   disk.info[idx[0]].b = 0;
   free_chain(idx[0]);

doc/tw/08-BlockDeviceDriver.md

@@ -108,7 +108,7 @@ struct virtq_used
 +------------------+
 ```
 
-為了精簡，我們會將 Buffer 抽離，完成 Device Driver 後會更方便我們在日後實現檔案系統。
+完成 Device Driver 方便我們在日後實現檔案系統。
 
 ### 指定寫入的 Sector