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>
52 lines
1.4 KiB
C
52 lines
1.4 KiB
C
/*
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* init/noinitramfs.c
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*
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* Copyright (C) 2006, NXP Semiconductors, All Rights Reserved
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* Author: Jean-Paul Saman <jean-paul.saman@nxp.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/init.h>
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#include <linux/stat.h>
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#include <linux/kdev_t.h>
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#include <linux/syscalls.h>
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/*
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* Create a simple rootfs that is similar to the default initramfs
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*/
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static int __init default_rootfs(void)
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{
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int err;
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err = sys_mkdir("/dev", 0755);
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if (err < 0)
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goto out;
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err = sys_mknod((const char __user *) "/dev/console",
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S_IFCHR | S_IRUSR | S_IWUSR,
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new_encode_dev(MKDEV(5, 1)));
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if (err < 0)
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goto out;
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err = sys_mkdir("/root", 0700);
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if (err < 0)
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goto out;
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return 0;
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out:
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printk(KERN_WARNING "Failed to create a rootfs\n");
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return err;
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}
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rootfs_initcall(default_rootfs);
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