Add freeramdisk(8)

Makefile

@@ -31,6 +31,7 @@ SRC = \
 	eject.c             \
 	fallocate.c         \
 	free.c              \
+	freeramdisk.c       \
 	fsfreeze.c          \
 	getty.c             \
 	halt.c              \
@@ -93,6 +94,7 @@ MAN1 = \
 
 MAN8 = \
 	ctrlaltdel.8        \
+	freeramdisk.8       \
 	fsfreeze.8          \
 	getty.8             \
 	halt.8              \

freeramdisk.8

@@ -0,0 +1,8 @@
+.TH FREERAMDISK 8 ubase-VERSION
+.SH NAME
+\fBfreeramdisk\fR - Free memory used by the loadlin ramdisk
+.SH SYNOPSIS
+\fBfreeramdisk\fR
+.SH DESCRIPTION
+\fBfreeramdisk\fR frees the memory that is used by the ramdisk.
+It uses the \fI/dev/ram\fR device node.

freeramdisk.c

@@ -0,0 +1,37 @@
+/* See LICENSE file for copyright and license details. */
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <sys/mount.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include "util.h"
+
+static void
+usage(void)
+{
+	eprintf("usage: %s\n", argv0);
+}
+
+int
+main(int argc, char *argv[])
+{
+	char *dev = "/dev/ram";
+	int fd;
+
+	ARGBEGIN {
+	default:
+		usage();
+	} ARGEND;
+
+	if (argc != 0)
+		usage();
+
+	if ((fd = open(dev, O_RDWR)) < 0)
+		eprintf("open: %s:", dev);
+	if (ioctl(fd, BLKFLSBUF, dev) < 0)
+		eprintf("BLKFLSBUF %s:", dev);
+	close(fd);
+	return EXIT_SUCCESS;
+}