Move /dev/zero to separate unit

This patch allows to present "/dev/zero" always in system and not
depending  of mem-command. Standard files allow to test other memory
devices, not only "mem", such as NOR, NAND, MCI-devices e.t.c.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 51 insertions, 0 deletions

diff --git a/commands/stddev.c b/commands/stddev.c
new file mode 100644
index 0000000000..18fea94074
--- /dev/null
+++ b/commands/stddev.c
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2011 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <init.h>
+
+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);