構建嵌入式Linux根文件系統

時間 2019-11-12

標籤構建嵌入 linux 文件系統欄目 Linux 简体版

原文原文鏈接

移植好了UBOOT和內核以後，即是構建linux根文件系統了。以 http://blog.chinaunix.net/u1/34474/showart_485837.html文章爲基礎進行修改。

1）建立根文件系統的基本目錄結構。
我把這個過程作成了shell腳本(文件名爲 mkroot) ，很方便！

#! /bin/sh echo "creatint rootfs dir......" mkdir rootfs cd rootfs echo "making dir : bin dev etc lib proc sbin sys usr" mkdir bin dev etc lib proc sbin sys usr #必備的8個目錄 mkdir usr/bin usr/lib usr/sbin lib/moduleshtml

 
 # Don't use mknod ,unless you run this Script as root !
 # mknod -m 600 dev/console c 5 1
 # mknod -m 666 dev/null c 1 3node

echo "making dir : mnt tmp var" mkdir mnt tmp var chmod 1777 tmp mkdir mnt/etc mnt/jffs2 mnt/yaffs mnt/data mnt/temp mkdir var/lib var/lock var/log var/run var/tmp chmod 1777 var/tmplinux

echo "making dir : home root boot" mkdir home root bootshell

echo "done"less

在你想要創建根文件系統的地方，運行：

[HongGe@Hzh1024n]$ ./mkroot creatint rootfs dir...... making dir : bin dev etc lib proc sbin sys usr making dir : mnt tmp var making dir : home root boot done [HongGe@Hzh1024n]$ cd rootfs/dev/ [HongGe@Hzh1024n dev]$ su 口令： [root@Hzh1024n dev]# mknod -m 600 console c 5 1;mknod -m 666 null c 1 3;exit exit [HongGe@Hzh1024n dev]$tcp

2）配置、編譯和安裝Busybox-1.9.0ide

[HongGe@Hzh1024n source]$ tar -xjvf busybox-1.9.0.tar.bz2工具

修改Makefile文件： oop

[HongGe@Hzh1024n busybox-1.9.0]$ pwd /home/work/hzh1024n/source/busybox-1.9.0 [HongGe@Hzh1024n busybox-1.9.0]$ kwrite Makefile ......(第174行附近) #ARCH ?= $(SUBARCH) #CROSS_COMPILE ?= ARCH = arm CROSS_COMPILE = /usr/local/arm/3.3.2/bin/arm-linux- [HongGe@Hzh1024n busybox-1.9.0]$ make menuconfigui

在原有的基礎上修改以下：

Busybox Settings --->
Installation Options --->
[*] Don't use /usr

(/home/work/hzh1024n/rootfs) BusyBox installation prefix

Busybox Library Tuning --->

[*] Support for /etc/networks

[*] Additional editing keys

[*] vi-style line editing commands

(15) History size

[*] History saving

[*] Tab completion

[*] Username completion

[*] Fancy shell prompts

Linux Module Utilities --->

[N] Support version 2.2.x to 2.4.x Linux kernels

Shells --->

--- Ash Shell Options 下的選項全選

[HongGe@Hzh1024n busybox-1.9.0]$ make ...... LINK busybox_unstripped Trying libraries: crypt m Library crypt is needed Library m is needed Final link with: crypt m [HongGe@Hzh1024n busybox-1.9.0]$ make install

3)安裝glibc庫

在開發板上只須要加載器和動態庫，假設要構建的根文件系統目錄爲/home/work/hzh1024n/rootfs,操做以下：

[HongGe@Hzh1024n busybox-1.9.0]$ cd /usr/local/arm/3.3.2/arm-linux/lib

[HongGe@Hzh1024n lib]$ cp *.so* /home/work/hzh1024n/rootfs/lib -d

上面複製的庫文件不是每一個都會被用到，能夠根據應用程序對庫的依賴關係保留須要用到的。經過ldd命令能夠查看一個程序會用到哪些庫，主機自帶的ldd命令不能查看交叉編譯出來的程序，有如下兩種替代方法。

*若是有uClibc-0.9.28的代碼，能夠進入utils子目錄生成ldd.host工具。

$cd uClibc-0.9.28/utils

$make ldd.host

而後將生成的ldd.host放到主機/usr/local/bin目錄下便可

$ldd.host busybox

*也可使用下面命令

$arm-linux-readelf -a "your binary" | grep "shared"

好比對於動態連接的Busybox，它的庫依賴關係以下。

0x00000001 (NEEDED) Shared library: [libcrypt.so.1] 0x00000001 (NEEDED) Shared library: [libm.so.6] 0x00000001 (NEEDED) Shared library: [libc.so.6]

4）修改和建立必要的文件。

   
   
           
            
             
              [HongGe@Hzh1024n busybox-1.9.0]$ cp -a examples/bootfloppy/etc/* /home/work/hzh1024n/rootfs/etc/
 [HongGe@Hzh1024n busybox-1.9.0]$ cd /home/work/hzh1024n/rootfs/etc/
  
             
            
          
 
 1、增長爲SHELL導入全局變量的文件/etc/profile
 [HongGe@Hzh1024n etc]$ kwrite profile
    
           
            
             
              # /etc/profile: system-wide .profile file for the Bourne shells
 echo
 echo "Processing /etc/profile... "
 # no-op
 
 # Set search library path
 echo "Set search library path in /etc/profile"
 export LD_LIBRARY_PATH=/lib:/usr/lib 
 
 # Set user path
 echo "Set user path in /etc/profile"
 PATH=/bin:/sbin:/usr/bin:/usr/sbin
 export PATH 
 
 # Set PS1 
 #注意：ash 除了SHELL變量外，支持\u、\h、\W、\$、\!、\n、\w 、\nnn（ASCII字符對應的八進制數）
 #以及\e[xx;xxm (彩色特效)等等！
 #並且前面還要多加一個 '\'！
  echo "Set PS1 in /etc/profile"
 export PS1="\\e[05;32m[$USER@\\w\\a]\\$\\e[00;34m"
  
 echo "Done"
 echo
 
  
             
            
          
 
  
 2、增長初始化文件
 [HongGe@Hzh1024n etc]$ kwrite inittab  
         
          
           
           ::sysinit:/etc/init.d/rcS
 ::restart:/sbin/init
 ::askfirst:-/bin/sh
 ::ctrlaltdel:/sbin/reboot
 ::shutdown:/bin/umount -a -r
 ::shutdown:/sbin/swapoff -a
  
           
          
        
 
   
 [HongGe@Hzh1024n etc]$ kwrite fstab  
       
        
         
          proc  /proc proc defaults    0 0
 tmpfs /tmp tmpfs defaults 0 0
 sysfs /sys sysfs defaults 0 0
 tmpfs /dev tmpfs  defaults 0 0
  
         
        
      
 
  
 
   
 3、增長初始化腳本
 [HongGe@Hzh1024n etc]$ kwrite init.d/rcS
    
        
         
          
           #! /bin/sh
 ifconfig eth0 192.168.1.67
 echo "----------mount all"
 /bin/mount -a
 /bin/mkdir /dev/pts
 echo "----------Starting mdev......"
 /bin/mount -t devpts devpts /dev/pts
 /bin/echo /sbin/mdev > /proc/sys/kernel/hotplug
 mdev -s
 echo "*********************************************************"
 echo "  HongGe Hzh1024n rootfs    "
 echo "   Wellcome  ! !         "
 echo "********************************************************"
  
          
         
       
 
  
 4、刪除備份文件
 [HongGe@Hzh1024n etc]$ rm *~ init.d/*~
  
 五、爲mdev建立配置文件
 [HongGe@Hzh1024n etc]$ vi mdev.conf
 建立一個mdev.conf文件，內容無關緊要。 
  
 到此爲止一個基本的根文件系統已經制做成功，下一步是掛載jffs2根文件系統。

若是要以掛載JFFS2格式的根文件系統，其基本方法就是將這個創建好的根文件系統製做成jffs2鏡像，燒到FLASH中，改改Linux的啓動參數便可。

 
          
              
           
          
            具體作法以下： 
           
           
           1、宿主機HOST編譯製作MTD工具 
           
          
              
           
          
            從 
           http://www.linux-mtd.infradead.org/下載mtd-utils 的tarball，能夠下載最新的。而後解壓，並在其目錄下 make 就好！ 
           
          
              
           
           
           2、製做根文件系統的JFFS2鏡像。 
           
          
              
           
          
            使用MTD工具中的mkfs.jffs2命令，具體作法以下： 
            
             
              
               mkfs.jffs2 -r /home/work/hzh1024n/rootfs -o rootfs.jffs2 -e 0x4000 --pad=0x500000 -s 0x200 -n
  
              
             
            
           
          
              
           
          
            各參數的意義： 
           
          
            (1)-r ： 指定要作成image的源資料夾. 
           
 (2)-o : 指定輸出image檔案的文件名. 
           
 (3)-e : 每一塊要抹除的block size，預設是64KB. 
           要注意，不一樣的flash, 其block size會不一樣. 
           個人是三星的K9F1208U0B.
 (4)--pad （-p）: 用16進制來表示所要輸出檔案的大小，也就是root.jffs2的size。很重要的是, 為了不浪費flash空間, 這個值最好符合flash driver所規劃的區塊大小.以個人板子來說，就是5MB. 
           
 (5)若是掛載後會出現相似：CLEANMARKER node found at 0x0042c000 has totlen 0xc != normal 0x0  的警告，則加上 -n 就會消失。 
           
 (6) 還有的選項，本身看幫助！-h 
           
          
              
           
           
           3、燒寫JFFS2鏡像到NAND FLASH。 
           
           
           將 rootfs.jffs2燒寫到FLASH中，注意內核掛載文件系統的參數，按照參數把文件系統燒寫到相關的位置當中。而後啓動開發板。 
             
              
               
                
 Uncompressing Linux........................................................................................................ done, booting the kernel.
 Linux version 2.6.22.6 (HongGe@Hzh1024n) (gcc version 3.3.2) #1 Wed Feb 07 11:18:36 CST 2008
 CPU: ARM920T [41129200] revision 0 (ARMv4T), cr=c0007177
 Machine: Hzh1024n
 Memory policy: ECC disabled, Data cache writeback
 CPU S3C2440A (id 0x32440001)
 S3C244X: core 405.000 MHz, memory 101.250 MHz, peripheral 50.625 MHz
 S3C24XX Clocks, (c) 2004 Simtec Electronics
 CLOCK: Slow mode (1.500 MHz), fast, MPLL on, UPLL on
 CPU0: D VIVT write-back cache
 CPU0: I cache: 16384 bytes, associativity 64, 32 byte lines, 8 sets
 CPU0: D cache: 16384 bytes, associativity 64, 32 byte lines, 8 sets
 Built 1 zonelists in Zone order, mobility grouping on. Total pages: 16256
 Kernel command line: noinitrd root=/dev/mtdblock4 rootfstype=jffs2 rw console=ttySAC0,115200 init=/linuxrc mem=64M
 irq: clearing pending ext status 00000200
 irq: clearing subpending status 00000003
 irq: clearing subpending status 00000002
 PID hash table entries: 256 (order: 8, 1024 bytes)
 timer tcon=00500000, tcnt a4ca, tcfg 00000200,00000000, usec 00001e57
 Console: colour dummy device 80x30
 console [ttySAC0] enabled
 Dentry cache hash table entries: 8192 (order: 3, 32768 bytes)
 Inode-cache hash table entries: 4096 (order: 2, 16384 bytes)
 Memory: 64MB = 64MB total
 Memory: 61464KB available (2960K code, 306K data, 120K init)
 Mount-cache hash table entries: 512
 CPU: Testing write buffer coherency: ok
 net_namespace: 64 bytes
 NET: Registered protocol family 16
 S3C2410 Power Management, (c) 2004 Simtec Electronics
 S3C2440: Initialising architecture
 S3C2440: IRQ Support
 S3C2440: Clock Support, DVS off
 S3C24XX DMA Driver, (c) 2003-2004,2006 Simtec Electronics
 DMA channel 0 at c4800000, irq 33
 DMA channel 1 at c4800040, irq 34
 DMA channel 2 at c4800080, irq 35
 DMA channel 3 at c48000c0, irq 36
 usbcore: registered new interface driver usbfs
 usbcore: registered new interface driver hub
 usbcore: registered new device driver usb
 NET: Registered protocol family 2
 IP route cache hash table entries: 1024 (order: 0, 4096 bytes)
 TCP established hash table entries: 2048 (order: 2, 16384 bytes)
 TCP bind hash table entries: 2048 (order: 1, 8192 bytes)
 TCP: Hash tables configured (established 2048 bind 2048)
 TCP reno registered
 NetWinder Floating Point Emulator V0.97 (double precision)
 JFFS2 version 2.2. (NAND) ©; 2001-2006 Red Hat, Inc.
 fuse init (API version 7.9)
 yaffs Feb 15 2008 10:10:34 Installing.
 io scheduler noop registered
 io scheduler anticipatory registered (default)
 io scheduler deadline registered
 io scheduler cfq registered
 Serial: 8250/16550 driver $Revision: 1.90 $ 4 ports, IRQ sharing enabled
 s3c2440-uart.: s3c2410_serial0 at MMIO 0x50000000 (irq = 70) is a S3C2440
 s3c2440-uart.1: s3c2410_serial1 at MMIO 0x50004000 (irq = 73) is a S3C2440
 s3c2440-uart.2: s3c2410_serial2 at MMIO 0x50008000 (irq = 76) is a S3C2440
 RAMDISK driver initialized: 16 RAM disks of 4096K size 1024 blocksize
 loop: module loaded
 dm9000 Ethernet Driver
 eth0: dm9000 at f6100300,f6100304 IRQ 51 MAC: 08:08:08:08:12:27
 Uniform Multi-Platform E-IDE driver Revision: 7.00alpha2
 ide: Assuming 50MHz system bus speed for PIO modes; override with idebus=xx
 S3C24XX NAND Driver, (c) 2004 Simtec Electronics
 s3c2440-nand s3c2440-nand: Tacls=1, 9ns Twrph0=4 39ns, Twrph1=1 9ns
 NAND device: Manufacturer ID: 0xec, Chip ID: 0x76 (Samsung NAND 64MiB 3,3V 8-bit)
 Scanning device for bad blocks
 Bad eraseblock 3579 at 0x037ec000
 Creating 7 MTD partitions on "NAND 64MiB 3,3V 8-bit":
 0x00000000-0x00020000 : "U-Boot-1.2.0"
 0x00020000-0x00030000 : "U-Boot-1.2.0 Parameter"
 0x00030000-0x00500000 : "Linux2.6.22.6 Kernel"
 0x00500000-0x00a00000 : "Root(cramfs)"
 0x00a00000-0x00f00000 : "Root(JFFS2)"
 0x00f00000-0x01400000 : "Root(YAFFS)"
 0x01400000-0x04000000 : "DATA"
 usbmon: debugfs is not available
 s3c2410-ohci s3c2410-ohci: S3C24XX OHCI
 s3c2410-ohci s3c2410-ohci: new USB bus registered, assigned bus number 1
 s3c2410-ohci s3c2410-ohci: irq 42, io mem 0x49000000
 usb usb1: configuration #1 chosen from 1 choice
 hub 1-:1.: USB hub found
 hub 1-:1.: 2 ports detected
 mice: PS/2 mouse device common for all mice
 S3C24XX RTC, (c) 2004,2006 Simtec Electronics
 s3c2410-rtc s3c2410-rtc: rtc disabled, re-enabling
 s3c2410-rtc s3c2410-rtc: rtc core: registered s3c as rtc0
 s3c2440-i2c s3c2440-i2c: slave address 0x10
 s3c2440-i2c s3c2440-i2c: bus frequency set to 98 KHz
 s3c2440-i2c s3c2440-i2c: i2c-: S3C I2C adapter
 S3C2410 Watchdog Timer, (c) 2004 Simtec Electronics
 s3c2410-wdt s3c2410-wdt: watchdog inactive, reset disabled, irq enabled
 TCP cubic registered
 NET: Registered protocol family 1
 RPC: Registered udp transport module.
 RPC: Registered tcp transport module.
 s3c2410-rtc s3c2410-rtc: setting system clock to 2008-02-17 12:46:08 UTC (1203252368)
 VFS: Mounted root (jffs2 filesystem).
 Freeing init memory: 120K
 init started: BusyBox v1.9.1 (2008-02-16 15:04:08 CST)
 starting pid 779, tty '': '/etc/init.d/rcS'
 ----------mount all
 ----------Starting mdev......
 *********************************************************
   HongGe Hzh1024n rootfs 
      Wellcome  ! ! 
 ********************************************************
 starting pid 783, tty '': '/bin/login'
 (none) login: root
 Password:
 login[783]: root login on 'console'
 
 Processing /etc/profile...
 Set search library path in /etc/profile
 Set user path in /etc/profile
 Set PS1 in /etc/profile
 Done
 
 [root@~]# 
  
               
              
            
  
          
 成功！！！