Linux內(nèi)核裁剪的自動化方法

1、Linux 內(nèi)核裁剪的自動化方法隨著廣泛地獲得使用并被移植到不同的平臺，Linux 內(nèi)核源代碼正在越來越大，比如, Linux 2.6.28 中， 文件數(shù)有 25282 個，大小有350M。 對于某一個平臺，真正需要的的文件其實不到 10%, 為了提高研發(fā)效率，我們應(yīng)當(dāng)刪除或者暫時刪除那些永遠(yuǎn)也不會用到的文件， 比如，可以使內(nèi)核的文件數(shù)縮減到5000， 從而節(jié)約拷貝、查找等的時間，提高研發(fā)效率。 本文提出一種高效、干凈的進(jìn)行內(nèi)核裁剪的辦法。以往，我們是通過手工刪除某些目錄來完成這個任務(wù)的。 手工刪除的缺點有：1.花時間，每次裁剪都要花 1 2 天， 才能將文件數(shù)目刪除到 5000 以下。2.不

2、夠干凈。 內(nèi)核代碼的 Makefile 以及 Kconfig 配置文件彼此的依賴性比較大， 即使某個目錄下的功能不被使用，直接刪除也會導(dǎo)致編譯出錯， 從而， 不得不修改相應(yīng)的 Makefile 以及 Kconfig 才能使編譯通過。 這留下一下隱患。3.恢復(fù)困難。 根據(jù)2）的描述，在我們對外發(fā)布完整版本而需要將以前刪除、修改的文件復(fù)原時，需要使用比較工具，仔細(xì)地比對，才能完整恢復(fù)， 這也非常花時間。 在經(jīng)歷了手工操作的痛苦之后，我們提出了一種自動化的方法。具體為：1.只刪除文件，不刪除目錄，保留 Makefile 及 Kconfig2.使用時，只需要填充一個配置表，其中，可以指定：1.刪除某個

3、文件， 比如：drivers/macintosh/adbhid.c2.刪除某個目錄下的匹配文件, 比如：include/asm-arm/hardware/*.h3.刪除某個目錄及其子目錄下的匹配文件，比如：drivers/block/#.c4.刪除某個目錄及其子目錄下的適合刪除文件, 比如：arch/alpha/#3.腳本會根據(jù)配置表，將相關(guān)的文件移動到一備份目錄，并保持原有的目錄結(jié)構(gòu)4.需要恢復(fù)時，只需要將備份目錄下的文件拷貝到原來的目錄，既可。 優(yōu)點如下：1.配置文件一次指定，可反復(fù)使用， 對同一內(nèi)核，不需要更改就可以再次運行。對不同內(nèi)核，只要稍作修改(內(nèi)核的目錄結(jié)構(gòu)不怎么變化)，既可復(fù)用

4、。2.配置文件指定后，裁剪及備份內(nèi)核的操作可以在幾秒內(nèi)完成，大大提高的效率。3.由于我們只刪除 *.c, *.h, *.txt 等文件，而不刪除編譯相關(guān)的配置文件，裁剪后的內(nèi)核特別干凈，不會影響編譯。打外部 patch 也特別容易。4.需要對外發(fā)布版本時，可以直接運行 restore.sh 腳本，瞬間完成。5.由于操作的可反復(fù)性，我們可以不斷優(yōu)化裁剪列表，得到最小內(nèi)核。最大程度地提高研發(fā)效率。 以下為例子配置文件：# README #here to specify which files(unused in your project) to move#you can specify a rel

5、ative directory with file name followed#you can specify # *.c to mean all c files below the dir # #.c to mean all c files below the dir and subdir# # to mean all files of known type below the dir and subdir# # Example:# drivers/macintosh/adbhid.c# drivers/dio/*.c# drivers/block/#.c# drivers/dio/#*ke

6、rnel version: 2.6.25# arch/#arch/alpha/#arch/avr32/#arch/blackfin/#arch/cris/#arch/frv/#arch/h8300/#arch/ia64/#arch/m32r/#arch/m68k/#arch/m68knommu/#arch/mips/#arch/mn10300/#arch/parisc/#arch/powerpc/#arch/ppc/#arch/s390/#arch/sh/#arch/sparc/#arch/sparc64/#arch/v850/#arch/x86/#arch/xtensa/# arch/arm

7、#arch/arm/mach-s3c2442/#arch/arm/mach-imx/#arch/arm/mach-s3c2440/#arch/arm/mach-omap2/#arch/arm/mach-clps711x/#arch/arm/mach-s3c2443/#arch/arm/plat-iop/#arch/arm/mach-davinci/#arch/arm/mach-ixp2000/#arch/arm/mach-iop13xx/#arch/arm/mach-integrator/#arch/arm/mach-iop33x/#arch/arm/plat-s3c24xx/#arch/ar

8、m/plat-s3c/#arch/arm/plat-omap/#arch/arm/mach-sa1100/#arch/arm/mach-omap1/#arch/arm/mach-aaec2000/#arch/arm/mach-ixp23xx/#arch/arm/mach-mx3/#arch/arm/mach-l7200/#arch/arm/mach-ixp4xx/#arch/arm/mach-at91/#arch/arm/mach-clps7500/#arch/arm/mach-rpc/#arch/arm/mach-s3c2400/#arch/arm/plat-mxc/#arch/arm/ma

9、ch-iop32x/#arch/arm/mach-footbridge/#arch/arm/mach-h720x/#arch/arm/mach-ep93xx/#arch/arm/mach-ebsa110/#arch/arm/mach-realview/#arch/arm/mach-s3c2412/#arch/arm/mach-ns9xxx/#arch/arm/mach-orion/#arch/arm/mach-shark/#arch/arm/mach-netx/#arch/arm/mach-pnx4008/#arch/arm/mach-s3c2410/#arch/arm/mach-lh7a40

10、x/#arch/arm/mach-ks8695/#arch/arm/mach-versatile/#arch/arm/mach-msm/# Documetation#Documentation/# drivers #drivers/acorn/#drivers/acpi/#drivers/amba/#drivers/ata/#drivers/atm/#drivers/auxdisplay/#drivers/cdrom/#drivers/dca/#drivers/dio/#drivers/edac/#drivers/eisa/#drivers/ide/#drivers/ieee1394/#dri

11、vers/infiniband/#drivers/isdn/#drivers/macintosh/#drivers/mca/#drivers/md/#drivers/memstick/#drivers/nubus/#drivers/of/#drivers/parisc/#drivers/parport/#drivers/pci/#drivers/pcmcia/#drivers/pnp/#drivers/ps3/#drivers/rapidio/#drivers/s390/#drivers/sbus/#drivers/sh/#drivers/sn/#drivers/ssb/#drivers/te

12、lephony/#drivers/thermal/#drivers/xen/#drivers/zorro/# drivers/char #drivers/char/agp/#drivers/char/mwave/#drivers/char/pcmcia/#drivers/char/rio/#drivers/char/drm/# drivers/net #drivers/net/appletalk/#drivers/net/ibm_emac/#drivers/net/ibm_newemac/#drivers/net/ixp2000/#drivers/net/pcmcia/#drivers/net

13、/tokenring/# drivers/scsi #drivers/scsi/aic7xxx/#drivers/scsi/aic7xxx_old/#drivers/scsi/aic94xx/#drivers/scsi/lpfc/#drivers/scsi/pcmcia/#drivers/scsi/qla2xxx/#drivers/scsi/qla4xxx/#drivers/scsi/sym53c8xx_2/# drivers/media #drivers/media/dvb/# drivers/media/video #drivers/media/video/bt8xx/#drivers/m

14、edia/video/cpia2/#drivers/media/video/cx23885/#drivers/media/video/cx25840/#drivers/media/video/em28xx/#drivers/media/video/ivtv/#drivers/media/video/pvrusb2/#drivers/media/video/saa7134/#drivers/media/video/sn9c102/#drivers/media/video/zc0301/# fs #fs/9p/#fs/afs/#fs/adfs/#fs/affs/#fs/bfs/#fs/befs/#

15、fs/coda/#fs/dlm/#fs/freevxfs/#fs/gfs2/#fs/hfs/#fs/hfsplus/#fs/hpfs/#fs/isofs/#fs/jbd/#fs/jbd2/#fs/jfs/#fs/minix/#fs/ntfs/#fs/ncpfs/#fs/ocfs2/#fs/qnx4/#fs/udf/#fs/ufs/#fs/xfs/# include #include/acpi/#include/asm-alpha/#include/asm-avr32/#include/asm-blackfin/#include/asm-cris/#include/asm-frv/#includ

16、e/asm-h8300/#include/asm-ia64/#include/asm-m32r/#include/asm-m68k/#include/asm-m68knommu/#include/asm-mips/#include/asm-mn10300/#include/asm-parisc/#include/asm-powerpc/#include/asm-ppc/#include/asm-s390/#include/asm-sh/#include/asm-sparc/#include/asm-sparc64/#include/asm-um/#include/asm-v850/#inclu

17、de/asm-x86/#include/asm-xtensa/#include/pcmcia/# include/asm-arm #include/asm-arm/arch-ks8695/#include/asm-arm/arch-iop33x/#include/asm-arm/arch-mxc/#include/asm-arm/arch-iop32x/#include/asm-arm/arch-ep93xx/#include/asm-arm/arch-h720x/#include/asm-arm/arch-iop13xx/#include/asm-arm/arch-ns9xxx/#inclu

18、de/asm-arm/arch-ebsa285/#include/asm-arm/arch-orion/#include/asm-arm/arch-ixp2000/#include/asm-arm/arch-s3c2400/#include/asm-arm/arch-msm/#include/asm-arm/arch-ixp4xx/#include/asm-arm/arch-lh7a40x/#include/asm-arm/arch-ebsa110/#include/asm-arm/arch-netx/#include/asm-arm/arch-imx/#include/asm-arm/arc

19、h-ixp23xx/#include/asm-arm/arch-davinci/#include/asm-arm/arch-sa1100/#include/asm-arm/plat-s3c24xx/#include/asm-arm/plat-s3c/#include/asm-arm/arch-l7200/#include/asm-arm/arch-versatile/#include/asm-arm/arch-clps711x/#include/asm-arm/arch-aaec2000/#include/asm-arm/arch-cl7500/#.h include/asm-arm/arch

20、-pnx4008/#include/asm-arm/arch-integrator/#include/asm-arm/arch-at91/#include/asm-arm/arch-shark/#include/asm-arm/arch-rpc/#include/asm-arm/arch-s3c2410/#include/asm-arm/arch-realview/# net/#net/ax25/#net/can/#net/decnet/#net/ipv6/#net/x25/# sound/#sound/aoa/#sound/isa/#sound/mips/#sound/oss/#sound/

21、parisc/#sound/pci/#sound/pcmcia/#sound/ppc/#sound/sh/#sound/sparc/#以下為備份腳本：#! /bin/bash#name: move.sh#function: move unused files from kernel to make size smaller#set -x function usage() echo Usage: $0 filename echo filename is the file that includes files to be deleted echo if not provided, filenam

22、e default to to_delete_files if $# -ne 1 ; then INPUT_FILE=to_cutoff_files echo inputfile default to $INPUT_FILEelse if $1 = -h ; then usage exit 0 fi INPUT_FILE=$1fi BASE_ORIG=cd .; pwd/BASE_NEW=cd files; pwd/FILES_LIST=.$INPUT_FILE_detailedrm -f $FILES_LIST #echo restore files#cp -a files/* ./ 2/d

23、ev/null#rm -rf files/* 2 /dev/null echo generate detailed file list.cat $INPUT_FILE | grep -v # | while read LINEdo if ! -z $LINE ; then if expr index $LINE # != 0 ; then DIR_ORIG=$BASE_ORIG$LINE DIR_ORIG=$DIR_ORIG%/* find $DIR_ORIG -name *.h $FILES_LIST find $DIR_ORIG -name *.c $FILES_LIST find $DIR_ORIG -name *.S $FILES_LIST find $DIR_ORIG -name