使用initramfs可以实现内核和文件系统在一个映像文件中，不过会增大内核体积，同时占用较多内存。 （1）准备根文件系统先准备好根文件系统，放到某个目录，不过为了方便和内核一起打包，可以放到内核源代码的usr/目录下，我的做法是在usr目录下建立了image目录，然后将可用的根文件系统的内容全部复制到image目录下： [chenxibing@localhost linux-2.6.27.8-smartarm3250]$ ls usr/image bin dev hello.c home lib mnt proc sbin tmp var boot etc hello_static init Makefile opt root sys usr 另外千万注意，initramfs识别的第一个进程名称为init，因此需要将原来根文件系统中busybox的linuxrc链接改名为init。 （2）配置内核配置内核，在General setup中使能initramfs， [*] Initial RAM filesystem and RAM disk (initramfs/initrd) support (./usr/image) Initramfs source file(s) 同时在Userspace binary formats 中使能elf文件支持： [*] Kernel support for ELF binaries （3）编译内核，加载运行make make uImage 编译出来后内核较大，由于根文件系统也比较大，我得到的内核有11M，加载后运行，解压的时间也变长了，但是内核运行之后很快就进入到shell界面了。 U-Boot 1.3.3 (Sep 1 2009 - 12:31:06) DRAM: 64 MB Flash: 2 MB NAND: 256 MiB In: serial Out: serial Err: serial Hit any key to stop autoboot: 0 U-Boot$ ru nfsboot HW MAC address: 00:01:90:00:C0:81 ENET:auto-negotiation complete ENET:Link status up ENET:FULL DUPLEX ENET:100MBase TFTP from server 192.168.7.238; our IP address is 192.168.7.236 Filename 'uImage'. Load address: 0x81000000 Loading: ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ############################################# done Bytes transferred = 12108228 (b8c1c4 hex) ## Booting kernel from Legacy Image at 81000000 ... Image Name: Linux-2.6.27.8 Image Type: ARM Linux Kernel Image (uncompressed) Data Size: 12108164 Bytes = 11.5 MB Load Address: 80008000 Entry Point: 80008000 Verifying Checksum ... OK Loading Kernel Image ... OK OK Starting kernel ... Uncompressing Linux.............................................................................................................................................................................................................................................................................................................................................. done, booting the kernel. Linux version 2.6.27.8 (chenxibing@localhost.localdomain) (gcc version 4.3.2 (crosstool-NG-1.3.1) ) #9 PREEMPT Thu Sep 3 09:55:52 CST 2009 CPU: ARM926EJ-S [41069264] revision 4 (ARMv5TEJ), cr=00053177 Machine: SmartARM3250 board with the LPC3250 Microcontroller Memory policy: ECC disabled, Data cache writeback CPU0: D VIVT write-back cache CPU0: I cache: 32768 bytes, associativity 4, 32 byte lines, 256 sets CPU0: D cache: 32768 bytes, associativity 4, 32 byte lines, 256 sets Built 1 zonelists in Zone order, mobility grouping on. Total pages: 16256 Kernel command line: root=/dev/mtdblock4 console=ttyS0,115200 mem=64M rootfstype=yaffs2 PID hash table entries: 256 (order: 8, 1024 bytes) Console: colour dummy device 80x30 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: 50972KB available (3352K code, 238K data, 10296K init) Calibrating delay loop... 129.84 BogoMIPS (lpj=649216) Mount-cache hash table entries: 512 CPU: Testing write buffer coherency: ok net_namespace: 288 bytes NET: Registered protocol family 16 Invalid board descriptor! LPC32XX DMA driver SCSI subsystem initialized 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 NET: Registered protocol family 1 NetWinder Floating Point Emulator V0.97 (double precision) JFFS2 version 2.2. (NAND) © 2001-2006 Red Hat, Inc. yaffs Sep 3 2009 09:30:12 Installing. msgmni has been set to 99 io scheduler noop registered io scheduler anticipatory registered io scheduler deadline registered io scheduler cfq registered (default) CLCD: ZHIYUAN LCD hardware, XVGA portrait display Console: switching to colour frame buffer device 128x48 Serial: 8250/16550 driver4 ports, IRQ sharing disabled serial8250.0: ttyS0 at MMIO 0x40090000 (irq = 9) is a 16550A console [ttyS0] enabled serial8250.0: ttyS1 at MMIO 0x40080000 (irq = 7) is a 16550A serial8250.0: ttyS2 at MMIO 0x40088000 (irq = 8) is a 16550A serial8250.0: ttyS3 at MMIO 0x40098000 (irq = 10) is a 16550A lpc32xx_hsuart.0: ttyTX0 at MMIO 0x40014000 (irq = 26) is a lpc32xx_hsuart lpc32xx_hsuart.0: ttyTX1 at MMIO 0x40018000 (irq = 25) is a lpc32xx_hsuart lpc32xx_hsuart.0: ttyTX2 at MMIO 0x4001c000 (irq = 24) is a lpc32xx_hsuart loop: module loaded LPC32XX_mii_bus: probed eth0: LPC32XX mac at 0x31060000 irq 29 eth0: attached PHY driver [Generic PHY] (mii_bus:phy_addr=0:00, irq=-1) Uniform Multi-Platform E-IDE driver ide0 at 0xc4866020-0xc486602e,0xc486602e on irq 86 Driver 'sd' needs updating - please use bus_type methods NAND device: Manufacturer ID: 0xec, Chip ID: 0xda (Samsung NAND 256MiB 3,3V 8-bit) Scanning device for bad blocks Bad eraseblock 627 at 0x04e60000 Creating 5 MTD partitions on "lpc32xx_nand": 0x00000000-0x00180000 : "smartarm3250-boot" 0x00180000-0x001c0000 : "smartarm3250-ubt-prms" 0x00200000-0x00600000 : "smartarm3250-kernel" 0x00600000-0x01600000 : "smartarm3250-safefs" 0x01600000-0x10000000 : "smartarm3250-rootfs" at25 spi0.0: 32 KByte at25256a eeprom, pagesize 64 I2C device at address 0x2d<6>ISP1301 Vendor ID : 0x04cc ISP1301 Product ID : 0x1301 ISP1301 Version ID : 0x0210 usb-ohci usb-ohci: at 0xf3120000, irq 0 usb-ohci usb-ohci: pnx4008 OHCI usb-ohci usb-ohci: new USB bus registered, assigned bus number 1 usb-ohci usb-ohci: irq 59, io mem 0xf3120000 usb usb1: configuration #1 chosen from 1 choice hub 1-0:1.0: USB hub found hub 1-0:1.0: 2 ports detected Initializing USB Mass Storage driver... usbcore: registered new interface driver usb-storage USB Mass Storage support registered. mice: PS/2 mouse device common for all mice input: LPC32xx Touchscreen as /class/input/input0 rtc-pcf8563 3-0051: chip found, driver version 0.4.3 rtc-pcf8563 3-0051: rtc core: registered rtc-pcf8563 as rtc0 rtc-lpc32xx rtc-lpc32xx: rtc core: registered rtc-lpc32xx as rtc1 i2c /dev entries driver PNX4008-WDT: PNX4008 Watchdog Timer: heartbeat 19 sec mmci-pl18x: DMA buffer(10000 bytes), P:0x812b0000, V:0xffdc0000 mmc0: MMCI rev 0 cfg 00 at 0x0000000020098000 irq 15,13 usbcore: registered new interface driver usbhid usbhid: v2.6:USB HID core driver Advanced Linux Sound Architecture Driver Version 1.0.17. ASoC version 0.13.2 UDA1380 Audio Codec 0.6<6>ALSA device list: No soundcards found. TCP cubic registered NET: Registered protocol family 17 RPC: Registered udp transport module. RPC: Registered tcp transport module. ieee80211: 802.11 data/management/control stack, git-1.1.13 ieee80211: Copyright (C) 2004-2005 Intel Corporation VFP support v0.3: implementor 41 architecture 1 part 10 variant 9 rev 1 rtc-pcf8563 3-0051: setting system clock to 2009-09-03 10:09:04 UTC (1251972544) Freeing init memory: 10296K #占用的内存很大 init started: BusyBox v1.11.2 () starting pid 326, tty '': '/etc/rc.d/rcS' Mounting /proc and /sys Setting the hostname to zlg Mounting filesystems Running sysctl Setting up networking on loopback device: Setting up networking on eth0: Adding static route for default gateway to 192.168.7.1: Setting nameserver to 192.168.7.1 in /etc/resolv.conf: Starting inetd: Starting the port mapper: starting pid 369, tty '': '-/bin/sh' [root@zlg /]# ls Makefile etc init proc tmp bin hello.c lib root usr boot hello_static mnt sbin var dev home opt sys [root@zlg /]# ls Makefile etc init proc tmp bin hello.c lib root usr boot hello_static mnt sbin var dev home opt sys [root@zlg /]# free total used free shared buffers Mem: 61328 44732 16596 0 0 Swap: 0 0 0 Total: 61328 44732 16596 |