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authorJean-Paul Saman <jean-paul.saman@nxp.com>2007-02-10 01:44:43 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-02-11 10:51:25 -0800
commitc33df4eaaf41fd3e34837a6ae9a5f9970c393d9f (patch)
treeb53498e6cd10a6da004b1835f285ed64493abdf2 /init/noinitramfs.c
parentdd65aa6690e30fdad84a62191c7ab37da89d9865 (diff)
downloadlinux-linaro-stable-c33df4eaaf41fd3e34837a6ae9a5f9970c393d9f.tar.gz
[PATCH] disable init/initramfs.c
The file init/initramfs.c is always compiled and linked in the kernel vmlinux even when BLK_DEV_RAM and BLK_DEV_INITRD are disabled and the system isn't using any form of an initramfs or initrd. In this situation the code is only used to unpack a (static) default initial rootfilesystem. The current init/initramfs.c code. usr/initramfs_data.o compiles to a size of ~15 kbytes. Disabling BLK_DEV_RAM and BLK_DEV_INTRD shrinks the kernel code size with ~60 Kbytes. This patch avoids compiling in the code and data for initramfs support if CONFIG_BLK_DEV_INITRD is not defined. Instead of the initramfs code and data it uses a small routine in init/noinitramfs.c to setup an initial static default environment for mounting a rootfilesystem later on in the kernel initialisation process. The new code is: 164 bytes of size. The patch is separated in two parts: 1) doesn't compile initramfs code when CONFIG_BLK_DEV_INITRD is not set 2) changing all plaforms vmlinux.lds.S files to not reserve an area of PAGE_SIZE when CONFIG_BLK_DEV_INITRD is not set. [deweerdt@free.fr: warning fix] Signed-off-by: Jean-Paul Saman <jean-paul.saman@nxp.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'init/noinitramfs.c')
-rw-r--r--init/noinitramfs.c52
1 files changed, 52 insertions, 0 deletions
diff --git a/init/noinitramfs.c b/init/noinitramfs.c
new file mode 100644
index 000000000000..f4c1a3a1b8c5
--- /dev/null
+++ b/init/noinitramfs.c
@@ -0,0 +1,52 @@
+/*
+ * init/noinitramfs.c
+ *
+ * Copyright (C) 2006, NXP Semiconductors, All Rights Reserved
+ * Author: Jean-Paul Saman <jean-paul.saman@nxp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * 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
+ */
+#include <linux/init.h>
+#include <linux/stat.h>
+#include <linux/kdev_t.h>
+#include <linux/syscalls.h>
+
+/*
+ * Create a simple rootfs that is similar to the default initramfs
+ */
+static int __init default_rootfs(void)
+{
+ int err;
+
+ err = sys_mkdir("/dev", 0755);
+ if (err < 0)
+ goto out;
+
+ err = sys_mknod((const char __user *) "/dev/console",
+ S_IFCHR | S_IRUSR | S_IWUSR,
+ new_encode_dev(MKDEV(5, 1)));
+ if (err < 0)
+ goto out;
+
+ err = sys_mkdir("/root", 0700);
+ if (err < 0)
+ goto out;
+
+ return 0;
+
+out:
+ printk(KERN_WARNING "Failed to create a rootfs\n");
+ return err;
+}
+rootfs_initcall(default_rootfs);