mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-30 07:34:12 +08:00
c33df4eaaf
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>
53 lines
1.4 KiB
C
53 lines
1.4 KiB
C
/*
|
|
* 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);
|