今天把android内核交叉编译后移植到我的2440开发板，下面是一些心得。

1、从http://code.google.com/p/android/downloads/list上下载linux-2.6.25-android-1.0_r1.tar.gz
2、解压到任意目录下，解压命令为tar tar –zxvf linux-2.6.25-android-1.0_r1.tar.gz。
3、解压2440板的交叉编译工具arm-linux-gcc-3.4.1.tar.bz2命令为tar xjvf arm-linux-  3.4.1.tar.bz2，将文件解压到用户目录，如/usr/local/arm/下。
4、添加当前路径进入环境变量，命令export PATH=/usr/local/arm/3.4.1/bin:$PATH
5、进入内核文件夹，如cd ~/kernel.git/
6、修改Makefile文件，gedit Makefile，如下
   CROSS_COMPILE        ?= arm-linux-
7、运行make menuconfig
  (1)确保System Type ---> ARM system type ()中的内容为Samsung S3C2410, S3C2412, S3C2413, S3C2440, S3C2442, S3C2443
  (2)确保System Type ---> S3C2410 Machines --->SMDK2410/A9M2410被勾选
   (3)取消选择与Goldfish相关的内容,如下：
Device Drivers ---> Character devices ---> < > Goldfish TTY Driver
Device Drivers ---> Power supply class support ---> < >   Goldfish battery driver (NEW)
Device Drivers ---> Real Time Clock ---> < >   GOLDFISH (NEW)
Device Drivers ---> Graphics support ---> Support for frame buffer devices ---> < >   Goldfish Framebuffer
device drivers->Graphics support->Console display driver support->[]VGA text console
  (4)选择S3C2410 LCD相关的内容
Device Drivers ---> Graphics support ---> Support for frame buffer devices ---> <*>   S3C2410 LCD framebuffer support
Device Drivers ---> Graphics support ---> Bootup logo ---> Standard black and white Linux logo
Device Drivers ---> Graphics support ---> Bootup logo ---> Standard 16-color Linux logo
Device Drivers ---> Graphics support ---> Bootup logo ---> Standard 224-color Linux logo
  (5) 选中Android内核必须选项
General setup ---> Use full shmem filesystem
General setup ---> Enable Android's Shared Memory Subsystem
System Type ---> Support Thumb user binaries
Device Drivers ---> Android ---> Android log driver
Device Drivers ---> Android ---> <*> Binder IPC Driver
  (6) 尽量选中Android内核可选选项
Device Drivers ---> Android ---> RAM buffer console
Device Drivers ---> Android ---> Android timed gpio driver
Device Drivers ---> Android ---> Only allow certain groups to create sockets
  (7)退出并保存.config
8、使用命令make zImage生成映像。

出现的一些问题
问题一：
  CC      arch/arm/kernel/asm-offsets.s
  cc1: error: invalid option `abi=aapcs-linux'
  make[1]: *** [arch/arm/kernel/asm-offsets.s] Error 1
  make: *** [prepare0] Error 2
解决方法：
    关闭kernel features -->Use EABI。

问题二：
  drivers/video/console/vgacon.c:494: error: `PCIMEM_BASE' undeclared (first use in this function)
  drivers/video/console/vgacon.c:494: error: (Each undeclared identifier is reported only once
解决方法：
  device drivers->
   Graphics support->
      Console display driver support->
         [ ]VGA text console（取消）

以上步骤中，省略了内核移植中的nandflash、lcd及yaffs2文件系统的支持，有机会补上去。

     下载到开发板上就可以了，能够启动起来，遗憾的是，这个内核没能启动我的yaffs2根文件系统。我有点纳闷了，不知道错在哪里，明明已经让内核支持了yaffs2文件系统了，但是下载内核及根文件系统后，重新启动Linux系统，到内核启动完成，要加载根文件系统的地方就中断了，具体错误如下：

Start Linux ... Copy linux kernel from 0x00120000 to 0x30008000, size = 0x00400000 ... Copy Kernel to SDRAM done,NOW, Booting Linux...... Uncompressing Linux..................................................................................................... done, booting the kernel. Linux version 2.6.25 (root@YWW) (gcc version 4.1.2) #4 Sun Jan 9 10:43:26 CST 2011 CPU: ARM920T [41129200] revision 0 (ARMv4T), cr=c0007177 Machine: SMDK2440 ATAG_INITRD is deprecated; please update your bootloader. Memory policy: ECC disabled, Data cache writeback CPU S3C2440A (id 0x32440001) S3C244X: core 400.000 MHz, memory 100.000 MHz, peripheral 50.000 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/mtdblock2 init=/linuxrc console=ttySAC0 irq: clearing pending ext status 000c0800 irq: clearing subpending status 00000003 irq: clearing subpending status 00000002 PID hash table entries: 256 (order: 8, 1024 bytes) timer tcon=00500000, tcnt a2c1, tcfg 00000200,00000000, usec 00001eb8 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: 61372KB available (2888K code, 444K data, 132K init) Mount-cache hash table entries: 512 CPU: Testing write buffer coherency: ok net_namespace: 152 bytes android_power_init android_power_init done NET: Registered protocol family 16 S3C2410 Power Management, (c) 2004 Simtec Electronics S3C2440: Initialising architecture S3C2440: IRQ Support 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 S3C244X: Clock Support, DVS off 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) ashmem: initialized yaffs Jan 9 2011 10:25:59 Installing. io scheduler noop registered io scheduler anticipatory registered (default) io scheduler deadline registered io scheduler cfq registered Console: switching to colour frame buffer device 30x40 fb0: s3c2410fb frame buffer device lp: driver loaded but no devices found ppdev: user-space parallel port driver Serial: 8250/16550 driver $Revision: 1.90 $ 4 ports, IRQ sharing enabled s3c2440-uart.0: 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 brd: module loaded loop: module loaded dm9000 Ethernet Driver, V1.30 Uniform Multi-Platform E-IDE driver 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=2, 20ns Twrph0=3 30ns, Twrph1=2 20ns NAND device: Manufacturer ID: 0xec, Chip ID: 0xda (Samsung NAND 256MiB 3,3V 8-bit) Scanning device for bad blocks Bad eraseblock 97 at 0x00c20000 Bad eraseblock 743 at 0x05ce0000 Bad eraseblock 917 at 0x072a0000 Bad eraseblock 954 at 0x07740000 Bad eraseblock 1195 at 0x09560000 Bad eraseblock 1346 at 0x0a840000 Bad eraseblock 1821 at 0x0e3a0000 Creating 3 MTD partitions on "NAND 256MiB 3,3V 8-bit": 0x00000000-0x00100000 : "Android Boot" 0x00120000-0x00520000 : "Android Kernel" 0x00520000-0x10000000 : "Android Yaffs2" 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 1-0:1.0: USB hub found hub 1-0:1.0: 2 ports detected mice: PS/2 mouse device common for all mice S3C24XX RTC, (c) 2004,2006 Simtec Electronics s3c2440-i2c s3c2440-i2c: slave address 0x10 s3c2440-i2c s3c2440-i2c: bus frequency set to 390 KHz s3c2440-i2c s3c2440-i2c: i2c-0: S3C I2C adapter S3C2410 Watchdog Timer, (c) 2004 Simtec Electronics s3c2410-wdt s3c2410-wdt: watchdog inactive, reset disabled, irq enabled logger: created 64K log 'log_main' logger: created 64K log 'log_events' logger: created 64K log 'log_radio' TCP cubic registered NET: Registered protocol family 1 RPC: Registered udp transport module. RPC: Registered tcp transport module. drivers/rtc/hctosys.c: unable to open rtc device (rtc0) yaffs: dev is 32505858 name is "mtdblock2" yaffs: passed flags "" yaffs: Attempting MTD mount on 31.2, "mtdblock2" yaffs: auto selecting yaffs2 block 57 is bad block 703 is bad block 877 is bad block 914 is bad block 1155 is bad block 1306 is bad block 1781 is bad yaffs: dev is 32505858 name is "mtdblock2" yaffs: passed flags "" yaffs: Attempting MTD mount on 31.2, "mtdblock2" block 57 is bad block 703 is bad block 877 is bad block 914 is bad block 1155 is bad block 1306 is bad block 1781 is bad List of all partitions: 0100 4096 ram0 (driver?) 0101 4096 ram1 (driver?) 0102 4096 ram2 (driver?) 0103 4096 ram3 (driver?) 0104 4096 ram4 (driver?) 0105 4096 ram5 (driver?) 0106 4096 ram6 (driver?) 0107 4096 ram7 (driver?) 0108 4096 ram8 (driver?) 0109 4096 ram9 (driver?) 010a 4096 ram10 (driver?) 010b 4096 ram11 (driver?) 010c 4096 ram12 (driver?) 010d 4096 ram13 (driver?) 010e 4096 ram14 (driver?) 010f 4096 ram15 (driver?) 1f00 1024 mtdblock0 (driver?) 1f01 4096 mtdblock1 (driver?) 1f02 256896 mtdblock2 (driver?) No filesystem could mount root, tried: ext2 msdos vfat romfs yaffs yaffs2 Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(31,2)

待解决。