implement /dev/zero

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 28 insertions, 0 deletions

diff --git a/commands/mem.c b/commands/mem.c
index ee09ed0303..2f91ff3cea 100644
--- a/commands/mem.c
+++ b/commands/mem.c
@@ -576,3 +576,31 @@ static int mem_init(void)
 
 device_initcall(mem_init);
 
+static ssize_t zero_read(struct cdev *cdev, void *buf, size_t count, ulong offset, ulong flags)
+{
+	memset(buf, 0, count);
+	return count;
+}
+
+static struct file_operations zeroops = {
+	.read  = zero_read,
+	.lseek = dev_lseek_default,
+};
+
+static int zero_init(void)
+{
+	struct cdev *cdev;
+
+	cdev = xzalloc(sizeof (*cdev));
+
+	cdev->name = "zero";
+	cdev->size = ~0;
+	cdev->ops = &zeroops;
+
+	devfs_create(cdev);
+
+	return 0;
+}
+
+device_initcall(zero_init);
+