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author | Jean-Paul Saman <jean-paul.saman@nxp.com> | 2007-02-10 09:44:43 (GMT) |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-02-11 18:51:25 (GMT) |
commit | c33df4eaaf41fd3e34837a6ae9a5f9970c393d9f (patch) | |
tree | b53498e6cd10a6da004b1835f285ed64493abdf2 /init | |
parent | dd65aa6690e30fdad84a62191c7ab37da89d9865 (diff) | |
download | linux-fsl-qoriq-c33df4eaaf41fd3e34837a6ae9a5f9970c393d9f.tar.xz |
[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')
-rw-r--r-- | init/Kconfig | 4 | ||||
-rw-r--r-- | init/Makefile | 7 | ||||
-rw-r--r-- | init/noinitramfs.c | 52 |
3 files changed, 62 insertions, 1 deletions
diff --git a/init/Kconfig b/init/Kconfig index a3f83e2..ab69422 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -280,8 +280,12 @@ config RELAY If unsure, say N. +if BLK_DEV_INITRD + source "usr/Kconfig" +endif + config CC_OPTIMIZE_FOR_SIZE bool "Optimize for size (Look out for broken compilers!)" default y diff --git a/init/Makefile b/init/Makefile index 633a268..0154aea 100644 --- a/init/Makefile +++ b/init/Makefile @@ -2,7 +2,12 @@ # Makefile for the linux kernel. # -obj-y := main.o version.o mounts.o initramfs.o +obj-y := main.o version.o mounts.o +ifneq ($(CONFIG_BLK_DEV_INITRD),y) +obj-y += noinitramfs.o +else +obj-$(CONFIG_BLK_DEV_INITRD) += initramfs.o +endif obj-$(CONFIG_GENERIC_CALIBRATE_DELAY) += calibrate.o mounts-y := do_mounts.o diff --git a/init/noinitramfs.c b/init/noinitramfs.c new file mode 100644 index 0000000..f4c1a3a --- /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); |