[更新] 添加 urandom 设备

Signed-off-by: liu2guang <1004383796@qq.com>

components/drivers/misc/rt_random.c

@@ -13,7 +13,7 @@
 static struct rt_device random_dev;
 static unsigned long seed;
 
-static  rt_uint16_t calc_random(void)
+static rt_uint16_t calc_random(void)
 {
     seed = 214013L * seed + 2531011L;
     return (seed >> 16) & 0x7FFF;   /* return bits 16~30 */
@@ -84,3 +84,76 @@ int random_device_init(void)
 }
 INIT_DEVICE_EXPORT(random_device_init);
 
+static struct rt_device urandom_dev;
+static unsigned long useed;
+
+static rt_uint16_t calc_urandom(void)
+{
+    useed = 214013L * useed + 2531011L;
+    return (useed >> 16) & 0x7FFF;   /* return bits 16~30 */
+}
+
+static rt_size_t random_uread(rt_device_t dev, rt_off_t pos, void *buffer, rt_size_t size)
+{
+    rt_uint16_t rand = calc_urandom();
+    ssize_t ret = sizeof(rand);
+    rt_memcpy(buffer, &rand, ret);
+    return ret;
+}
+
+static rt_size_t random_uwrite(rt_device_t dev, rt_off_t pos, const void *buffer, rt_size_t size)
+{
+    ssize_t ret = sizeof(useed);
+    rt_memcpy(&useed, buffer, ret);
+    return ret;
+}
+
+static rt_err_t random_ucontrol(rt_device_t dev, int cmd, void *args)
+{
+    return RT_EOK;
+}
+
+#ifdef RT_USING_DEVICE_OPS
+const static struct rt_device_ops urandom_ops =
+{
+    RT_NULL,
+    RT_NULL,
+    RT_NULL,
+    random_uread,
+    random_uwrite,
+    random_ucontrol
+};
+#endif
+
+int urandom_device_init(void)
+{
+    static rt_bool_t init_ok = RT_FALSE;
+
+    if (init_ok)
+    {
+        return 0;
+    }
+    RT_ASSERT(!rt_device_find("urandom"));
+    urandom_dev.type    = RT_Device_Class_Miscellaneous;
+
+#ifdef RT_USING_DEVICE_OPS
+    urandom_dev.ops     = &urandom_ops;
+#else
+    urandom_dev.init    = RT_NULL;
+    urandom_dev.open    = RT_NULL;
+    urandom_dev.close   = RT_NULL;
+    urandom_dev.read    = random_uread;
+    urandom_dev.write   = random_uwrite;
+    urandom_dev.control = random_ucontrol;
+#endif
+
+    /* no private */
+    urandom_dev.user_data = RT_NULL;
+
+    rt_device_register(&urandom_dev, "urandom", RT_DEVICE_FLAG_RDWR);
+
+    init_ok = RT_TRUE;
+
+    return 0;
+}
+INIT_DEVICE_EXPORT(urandom_device_init);