arm内核移植过程

转自： http://student.csdn.net/space.php?uid=366890&do=blog&id=28865

1 内核移植过程

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1.1 下载linux 内核

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??? 从http://www.kernel.org/pub/linux/kernel/v2.6/linux-2.6.14.1.tar.bz2

下载linux-2.6.14.1 内核至home/arm/dev_home/kernel.

[root@localhost ~]#su arm

[arm@localhost ~]#cd $KERNEL

[arm@localhost kernel]#tar -xzvf linux-2.6.14.1.tar.gz

[arm@localhost kernel]# pwd

/home/arm/dev_home/kernel

[arm@localhost kernel]# cd linux-2.6.14

?????? 进入内核解压后的目录，以后示例中，只要是相对路径全部是相对于

?????? /home/arm/dev_home/kernel/linux-2.6.14/此目录

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1.2 修改 Makefile

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修改内核目录树根下的的Makefile,指明交叉编译器

[arm@localhost linux-2.6.14]# vi Makefile

找到ARCH 和CROSS_COMPILE ，修改

ARCH?????? ?= arm

CROSS_COMPILE??? ?= arm-linux-

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然后设置你的PATH 环境变量，使其可以找到你的交叉编译工具链

[arm@localhost linux-2.6.14]# echo $PATH

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/usr/local/arm/3.4.4/bin:/usr/kerberos/bin:/usr/local/bin:/usr/bin:/bin:/usr/X11R6/bin:/home/ly/bin

如果/usr/local/arm/3.4.4/bin 搜索路径,加入下面语句在~/.bashrc 中

[arm@localhost linux-2.6.14]# vi ~/.bashrc

export PATH=/usr/local/arm/3.4.4/bin:$PATH

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再重新登陆.

[arm@localhost linux-2.6.14]#su arm

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1.3 设置flash 分区

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此处一共要修改 3个文件，分别是:

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1.3.1指明分区信息

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在arch/arm/mach-s3c2410/devs.c 文件中:

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[arm@localhost linux-2.6.14]$ vi arch/arm/mach-s3c2410/devs.c

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添加如下内容：

#include <linux/mtd/partitions.h>

#include <linux/mtd/nand.h>

#include <asm/arch/nand.h>

...

/* NAND Controller */

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1.建立Nand Flash 分区表

/* 一个Nand Flash 总共64MB,按如下大小进行分区 */

static struct mtd_partition partition_info[] ={

??????? { /* 1MB? */

???????????????? name: "bootloader",

???????????????? size:? 0x00100000,

???????????????? offset: 0x0,

??????? },{ /* 3MB */

???????????????? name: "kernel",

???????????????? size:? 0x00300000,

???????????????? offset: 0x00100000,{ /* 40MB */

???????????????? name: "root",

???????????????? size:? 0x02800000,

???????????????? offset: 0x00400000,{ /* 20MB */

???????????????? name: "user",

???????????????? size: 0x00f00000,

???????????????? offset: 0x02d00000,

??????? }

};

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name: 代表分区名字

size: 代表flash 分区大小(单位：字节)

offset: 代表flash 分区的起始地址(相对于0x0 的偏移)

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?目标板计划分4 个区，分别存放bootloader,kernel,rootfs 以及以便以后扩展使用的用户文件系统空间。

各分区在Nand flash 中起始地址. 分区大小. 记录如下：

----------------------- 页面 54-----------------------

?bootloader:

??????? start: 0x00000000

??????? len:??? 0x00100000

??????? 1MB

?kernel:

??????? start: 0x00100000

??????? len:??? 0x00300000

??????? 3MB

?rootfs:

??????? start: 0x00400000

??????? len:??? 0x02800000

??????? 40MB

?User:

??????? start: 0x02c00000

??????? len:??? 0x01400000

??????? 20MB

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2. 加入Nand Flash 分区

struct s3c2410_nand_set nandset ={

??????? nr_partitions: 4,?????????? /* the number of partitions */

??????? partitions: partition_info,/* partition table????????? */

};

nr_partitions: 指明partition_info 中定义的分区数目

partitions: 分区信息表

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3. 建立Nand Flash 芯片支持

struct s3c2410_platform_nand superlpplatform={

??????? tacls:0,

??????? twrph0:30,

??????? twrph1:0,

??????? sets: &nandset,

??????? nr_sets: 1,

};

tacls,twrph0,twrph1 的意思见S3C2410 手册的6-3,这3 个值最后会被设置到NFCONF 中,见S3C2410 手册6-6.

sets: 支持的分区集

nr_set:分区集的个数

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4. 加入Nand Flash 芯片支持到Nand Flash 驱动

另外，还要修改此文件中的s3c_device_nand 结构体变量,添加对dev 成员的赋值

struct platform_device s3c_device_nand = {

??????? .name??????????? = "s3c2410-nand",???? /* Device name */

??????? .id????????????? = -1,???????????????? /* Device ID??? */

??????? .num_resources?????? = ARRAY_SIZE(s3c_nand_resource),

??????? .resource??????? = s3c_nand_resource,/* Nand Flash Controller Registers */

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??????? /* Add the Nand Flash device */

??????? .dev = {

????????????????? .platform_data = &superlpplatform

????????? }

};

----------------------- 页面 55-----------------------

name:? 设备名称

id: 有效设备编号,如果只有唯一的一个设备为-1,有多个设备从0 开始计数.

num_resource: 有几个寄存器区

resource: 寄存器区数组首地址

dev: 支持的Nand Flash 设备

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1.3.2 指定启动时初始化

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kernel 启动时依据我们对分区的设置进行初始配置?

修改arch/arm/mach-s3c2410/mach-smdk2410.c 文件

[arm@localhost linux-2.6.14]$ vi arch/arm/mach-s3c2410/mach-smdk2410.c

修改smdk2410_devices[].指明初始化时包括我们在前面所设置的flash 分区信息

static struct platform_device *smdk2410_devices[] __initdata = {

??????? &s3c_device_usb,

??????? &s3c_device_lcd,

??????? &s3c_device_wdt,

??????? &s3c_device_i2c,

??????? &s3c_device_iis,

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??????? /* 添加如下语句即可 */

??????? &s3c_device_nand,

};

保存,退出。

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1.3.3 禁止 Flash ECC校验?

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??? 我们的内核都是通过UBOOT 写到Nand Flash 的,UBOOT 通过的软件ECC 算法产生ECC 校验码,这与内核

校验的ECC 码不一样,内核中的ECC 码是由S3C2410 中Nand Flash 控制器产生的. 所以,我们在这里选择禁止

内核ECC 校验.

修改drivers/mtd/nand/s3c2410.c 文件:

[arm@localhost linux-2.6.14]$ vi drivers/mtd/nand/s3c2410.c

找到s3c2410_nand_init_chip()函数，在该函数体最后加上一条语句:

chip->eccmode = NAND_ECC_NONE;

保存,退出。

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OK.我们的关于flash 分区的设置全部完工.

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1.4 配置内核

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1.4.1 支持启动时挂载 devfs

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为了我们的内核支持devfs 以及在启动时并在/sbin/init 运???????????????? 之前能自动挂载/dev 为devfs 文件系统，修改

fs/Kconfig 文件

[arm@localhost linux-2.6.14]$ vi fs/Kconfig

找到menu "Pseudo filesystems"

添加如下语句：

config DEVFS_FS

??????? bool "/dev file system support (OBSOLETE)"

??????? default y

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config DEVFS_MOUNT

----------------------- 页面 56-----------------------

??????? bool "Automatically mount at boot"

??????? default y

??????? depends on DEVFS_FS

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1.4.2 配置内核产生.config 文件

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[arm@localhost linux-2.6.14]$ cp arch/arm/configs/smdk2410_defconfig .config

[arm@localhost linux-2.6.14]$ make menuconfig

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在smdk2410_defconfig 基础上，我所增删的内核配置项如下：

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Loadable module support? --->

????????????????????????? [*] Enable loadable module support

?????????????????????????????????? [*] Automatic kernel module loading

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System Type? ---> [*] S3C2410 DMA support

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Boot options? ---> Default kernel command string:

???????? noinitrd root=/dev/mtdblock2 init=/linuxrc console=ttySAC0,115200

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???????? #说明：mtdblock2 代表我的第3 个flash 分区，它是我的rootfs

???????? #?? console=ttySAC0,115200 使kernel 启动期间的信息全部输出到串口0 上.

???????? #?? 2.6 内核对于串口的命名改为ttySAC0 ，但这不影响用户空间的串口编程。

???????? #?? 用户空间的串口编程针对的仍是/dev/ttyS0 等

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Floating point emulation --->

????????????????????????? [*] NWFPE math emulation

??????????????????????????? This is necessary to run most binaries!!!

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#接下来要做的是对内核MTD 子系统的设置

Device Drivers? --->

???????? Memory Technology Devices (MTD)? --->

????????????????????????? [*] MTD partitioning support

??????????????????????????? #支持MTD 分区，这样我们在前面设置的分区才有意义

????????????????????????? [*] Command line partition table parsing

??????????????????????????? #支持从命令行设置flash 分区信息，灵活

?????????????????????????????????? RAM/ROM/Flash chip drivers? --->

??????????????????????????????????? <*> Detect flash chips by Common Flash

???????????????????????????????????? Interface (CFI) probe

??????????????????????????????????? <*> Detect non-CFI AMD/JEDEC-compatible flash chips

??????????????????????????????????? <*> Support for Intel/Sharp flash chips

??????????????????????????????????? <*> Support for AMD/Fujitsu flash chips

??????????????????????????????????? <*> Support for ROM chips in bus mapping

?????????????????????????????????? NAND Flash Device Drivers? --->

??????????????????????????????????? <*> NAND Device Support

??????????????????????????????????? <*> NAND Flash support for S3C2410/S3C2440 SoC

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???????? Character devices? --->

????????????????????????? [*] Non-standard serial port support

????????????????????????? [*] S3C2410 RTC Driver

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#接下来做的是针对文件系统的设置，本人实验时目标板上要上的文件系统是cramfs,故做如下配置

----------------------- 页面 57-----------------------

File systems? --->

????????????????????????? <> Second extended fs support? #去除对ext2 的支持

???????????????? Pseudo filesystems? --->

????????????????????????? [*] /proc file system support

????????????????????????? [*] Virtual memory file system support (former shm fs)

????????????????????????? [*] /dev file system support (OBSOLETE)

????????????????????????? [*] Automatically mount at boot (NEW)

??????????????????????????? #这里会看到我们前先修改fs/Kconfig 的成果，devfs 已经被支持上了

???????????????? Miscellaneous filesystems? --->

????????????????????????? <*> Compressed ROM file system support (cramfs)

??????????????????????????? #支持cramfs

???????????????? Network File Systems? --->

????????????????????????? <*> NFS file system support

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保存退出，产生.config 文件.

.config 文件能从提供的2.4.14.1 的内核包中找到,文件名为config.back.

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1.4.3编译内核

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[arm@localhost linux-2.6.14]$ make zImage

注意：若编译内核出现如下情况

? LD???? .tmp_vmlinux1

? arm-linux-ld:arch/arm/kernel/vmlinux.lds:1439: parse error

? make: *** [.tmp_vmlinux1] Error 1

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解决方法：修改arch/arm/kernel/vmlinux.lds

[arm@localhost linux-2.6.14]$ vi arch/arm/kernel/vmlinux.lds

将文件尾2 条的ASSERT 注释掉 （1439??????????????????? ）

/* ASSERT((__proc_info_end - __proc_info_begin),"missing CPU support") */

/* ASSERT((__arch_info_end - __arch_info_begin),"no machine record defined") */

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然后重新make zImage 即可

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1.4.4 下载zImage到开发板

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CRANE2410 # tftp 0x30008000 zImage

TFTP from server 192.168.1.6; our IP address is 192.168.1.5

Filename 'zImage'.

Load address: 0x30008000

Loading: #################################################################

???????? #################################################################

???????? #################################################################

???????? #############################

done

Bytes transferred = 1142856 (117048 hex)

CRANE2410 # bootm 0x30008000

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1.4.5 目标板启动信息如下

IRQ Stack: 33fc149c

FIQ Stack: 33fc249c

1

----------------------- 页面 58-----------------------

1

DRAM Configuration:

Bank #0: 30000000 64 MB

1

NAND:64 MB

In:?? serial

Out:?? serial

Err:? serial

Hit any key to stop autoboot:? 0

zImage magic = 0x016f2818

NOW,Booting Linux......

Uncompressing Linux............................................................................ don.Linux version 2.6.14.1 (arm@dozec) (gcc

version 3.3.2) #15 Thu Jul 6 14:26:29 CST 2006

CPU: ARM920Tid(wb) [41129200] revision 0 (ARMv4T)

Machine: SMDK2410

Warning: bad configuration page,trying to continue

Memory policy: ECC disabled,Data cache writeback

CPU S3C2410A (id 0x32410002)

S3C2410: core 202.800 MHz,memory 101.400 MHz,peripheral 50.700 MHz

S3C2410 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,8 sets

Built 1 zonelists

Kernel command line: noinitrd root=/dev/mtdblock2 init=/linuxrc console=ttySAC0,115200

irq: clearing subpending status 00000002

PID hash table entries: 128 (order: 7,2048 bytes)

timer tcon=00500000,tcnt a509,tcfg 00000200,00000000,usec 00001e4c

Console: colour dummy device 80x30

Dentry cache hash table entries: 4096 (order: 2,16384 bytes)

Inode-cache hash table entries: 2048 (order: 1,8192 bytes)

Memory: 16MB = 16MB total

Memory: 13712KB available (1927K code,422K data,104K init)

Mount-cache hash table entries: 512

CPU: Testing write buffer coherency: ok

softlockup thread 0 started up.

NET: Registered protocol family 16

S3C2410: Initialising architecture

SCSI subsystem initialized

usbcore: registered new driver usbfs

usbcore: registered new driver hub

S3C2410 DMA Driver,(c) 2003-2004 Simtec Electronics

DMA channel 0 at c1800000,irq 33

DMA channel 1 at c1800040,irq 34

DMA channel 2 at c1800080,irq 35

DMA channel 3 at c18000c0,irq 36

NetWinder Floating Point Emulator V0.97 (double precision)

devfs: 2004-01-31 Richard Gooch (rgooch@atnf.csiro.au)

devfs: boot_options: 0x1

Console: switching to colour frame buffer device 80x25

fb0: Virtual frame buffer device,using 1024K of video memory

----------------------- 页面 59-----------------------

S3C2410 RTC,(c) 2004 Simtec Electronics

s3c2410_serial0 at MMIO 0x50000000 (irq = 70) is a S3C2410

s3c2410_serial1 at MMIO 0x50004000 (irq = 73) is a S3C2410

s3c2410_serial2 at MMIO 0x50008000 (irq = 76) is a S3C2410

io scheduler noop registered

io scheduler anticipatory registered

io scheduler deadline registered

io scheduler cfq registered

RAMDISK driver initialized: 16 RAM disks of 4096K size 1024 blocksize

Cirrus Logic CS8900A driver for Linux (Modified for SMDK2410)

eth0: CS8900A rev E at 0xe0000300 irq=53,no eeprom,addr: 08: 0:3E:26:0A:5B

S3C24XX NAND Driver,(c) 2004 Simtec Electronics

s3c2410-nand: mapped registers at c1980000

s3c2410-nand: timing: Tacls 10ns,Twrph0 30ns,Twrph1 10ns

NAND device: Manufacturer ID: 0xec,Chip ID: 0x76 (Samsung NAND 64MiB 3,3V 8-bit)

NAND_ECC_NONE selected by board driver. This is not recommended !!

Scanning device for bad blocks

Creating 4 MTD partitions on "NAND 64MiB 3,3V 8-bit":

0x00000000-0x00100000 : "bootloader"

0x00100000-0x00500000 : "kernel"

0x00500000-0x02d00000 : "root"

0x02d00000-0x03c00000 : "User"

usbmon: debugfs is not available

116x: driver isp116x-hcd,05 Aug 2005

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: Product: S3C24XX OHCI

usb usb1: Manufacturer: Linux 2.6.14.1 ohci_hcd

usb usb1: SerialNumber: s3c24xx

hub 1-0:1.0: USB hub found

hub 1-0:1.0: 2 ports detected

sl811: driver sl811-hcd,19 May 2005

usbcore: registered new driver cdc_acm

drivers/usb/class/cdc-acm.c: v0.23:USB Abstract Control Model driver for USB modems and ISDN

adaptesdrivers/usb/class/bluetty.c: USB Bluetooth support registered

usbcore: registered new driver bluetty

drivers/usb/class/bluetty.c: USB Bluetooth tty driver v0.13

usbcore: registered new driver usblp

drivers/usb/class/usblp.c: v0.13: USB Printer Device Class driver

Initializing USB Mass Storage driver...

usbcore: registered new driver usb-storage

USB Mass Storage support registered.

mice: PS/2 mouse device common for all mice

NET: Registered protocol family 2

IP route cache hash table entries: 256 (order: -2,1024 bytes)

TCP established hash table entries: 1024 (order: 0,4096 bytes)

TCP bind hash table entries: 1024 (order: 0,4096 bytes)

TCP: Hash tables configured (established 1024 bind 1024)

TCP reno registered

TCP bic registered

NET: Registered protocol family 1

----------------------- 页面 60-----------------------

NET: Registered protocol family 17

Reading data from NAND FLASH without ECC is not recommended

VFS: Mounted root (cramfs filesystem) readonly.

Mounted devfs on /dev

Freeing init memory: 104K

Reading data from NAND FLASH without ECC is not recommended

mount /etc as ramfs

re-create the /etc/mtab entries

------------mount /dev/shm as tmpfs

------------mount /proc as proc

------------mount /sys as sysfs

init started:? BusyBox v1.1.3 (2006.07.03-03:43+0000) multi-call binary

Starting pid 28,console /dev/tts/0: '/etc/init.d/rcS'

in /etc/init.d/rcS

-------------/sbin/ifconfig eth0 192.168.1.5

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Please press Enter to activate this console.

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1.5 Linux 下cs8900a 的移植说明

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1.5.1 为 cs8900a建立编译菜单

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1. 拷贝到文件

把cs8900a 的压缩包拷贝到arm 用户下的dev_home/localapps/

[arm@localhost localapps]$ tar -xzvf cs8900a.tar.gz

[arm@localhost localapps]$cd cs8900a

[arm@localhost cs8900a]$cp???? cs8900a.c $KERNEL/linux-2.6.14.1/drivers/net/

[arm@localhost cs8900a]$cp cs8900.h $KERNEL/linux-2.6.14.1/drivers/net/

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2. 修改Kconfig 文件

[arm@localhost cs8900a]$vi $KERNEL/linux-2.6.14.1/drivers/net/Kconfig

#加入如下内容

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??????? config CS8900a

??????? tristate "CS8900a support"

??????? depends on NET_ETHERNET && ARM && ARCH_SMDK2410

??????? ---help---

???????? Support for CS8900A chipset based Ethernet cards. If you have a network (Ether

???????? net) card of this type,say Y and read the? Ethernet-HOWTO,available from? as

???????? well as.

???????? To compile this driver as a module,choose M here and read.

???????? The module will be called cs8900.o.

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3. 修改Makefile 文件

[arm@localhost cs8900a]$vi $KERNEL/linux-2.6.14.1/drivers/net/Makefile

#加入如下内容

???????? obj-$(CONFIG_CS8900a)??????????? += cs8900a.o

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1.5.2 修改 S3C2410相关信息

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1. 加入CS8900A 在内存中的起始位置

----------------------- 页面 61-----------------------

[arm@localhost cs8900a]$cp reg-cs8900.h $KERNEL/linux-2.6.14.1/include/asm-arm/arch-s3c2410/

cs8900.h 的内容如下:

#ifndef _INCLUDE_CS8900A_H_

#define _INCLUDE_CS8900A_H_

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#include <linux/config.h>

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#define pSMDK2410_ETH_IO?????????? 0x19000000 /* S3C2410_CS3 0x18000000 */

#define vSMDK2410_ETH_IO?????????? 0xE0000000

#define SMDK2410_ETH_IRQ?????????? IRQ_EINT9

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#endif

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2. 加入cs8900A 的物理地址到虚拟地址的映射

[arm@localhost cs8900a]$vi $KERNEL/linux-2.6.14.1/arch/arm/mach-s3c2410/mach-smdk2410.c

/* 加入如下内容 */

static struct map_desc smdk2410_iodesc[] __initdata = {

? {vSMDK2410_ETH_IO,0x19000000,SZ_1M,MT_DEVICE} /* Add this line */

};

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2 创建 uImage

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2.1 相关技术背景介绍

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??? 前面已经介绍了内核编译后，生成zImage 的内核镜像文件。该镜像文件可以通过U-BOOT 提供的go 命令，

跳转执行，引导内核。同时在u-boot-1.1.4 的tools? 目录下，提供了生成uImage 的工具mkimage 命令，在生成

u-boot 的二进制镜像文件的同时，mkimage 命令会同时编译生成，无需另外编译。通过mkimage 命令，在

zImage 中加入头文件 （镜像头长0x40,真正的内核入口向后偏移了0x40 大小），生成uImage 镜像文件，该文

件就是执?????? bootm 所需的内核镜像文件。

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2.2 在内核中创建 uImage 的方法

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2.2.1 获取 mkimage工具

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?? 2.6 内核树的Makefile 提供了创建uImage 的方法，但需要我们提供相应的mkimage 命令。

?? 所以首先拷贝u-boot 中tools? 目录下编译后生成的mkimage 到/usr/bin/下，然后便可以在内核根目录下通过

make uImage

?? 来创建uImage 文件。该文件生成在arch/arm/boot/下。

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2.2.2 修改内核的 Makefile文件

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[arm@localhost linux-2.6.14.1]$ vi arch/arm/boot/Makefile

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#MKIMAGE 变量记录mkimage 命令的路径mkuboot.sh 脚本文件可以scripts? 目录中找到

MKIMAGE??????? := $(srctree)/scripts/mkuboot.sh

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#zreladdr-y 与params_phys-y 可以在arch/arm/mach-s3c2410/Makefile.boot 当中找到

ZRELADDR???? := $(zreladdr-y)

PARAMS_PHYS := $(params_phys-y)

INITRD_PHYS := $(initrd_phys-y)

----------------------- 页面 62-----------------------

#生成uImage 的mkImage 命令行，其中需要关注的就是-a 与 -e 参数。

#参数-a：指明uImage 加载的SDRAM 地址，内核默认指定加载地址为0x30008000 。

#?????? u-boot 引导时，bootm 命令跳到与上相同位置执行，检查完镜像头后，它会跳到内核真正的入口点开

始执??? 。

#参数-e：指明uImage 中刨去镜像头后真正的内核入口地址。

#??? 镜像头为0x40 长，故此处指定为0x30008040 。

#?????? u-boot 引导时，go 命令可以直接指定此位置。go 命令不检查镜像头。

quiet_cmd_uimage = UIMAGE? $@

????? cmd_uimage = $(CONFIG_SHELL) $(MKIMAGE) -A arm -O linux -T kernel /

????????????????? -C none -a $(ZRELADDR) -e 0x30008040 /

????????????????? -n 'Linux-$(KERNELRELEASE)' -d $< $@

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3追加实验记录

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以同样方式移植其他2.6 主线内核，出现问题如下：

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3.1移植 linux-2.6.15.7

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??? 编译通过，启动时显示：

?????? VFS: Cannot open root device "mtdblock2" or unknown-block(31,2)

?????? Please append a correct "root=" boot option

?????? Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(31,2)

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3.2 移植 linux-2.6.16.21

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???? 编译通过，启动时显示：

?????? VFS: Cannot open root device "mtdblock2" or unknown-block(31,2)

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3.3 移植 linux-2.6.17

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?????? 编译失败

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4 参考资料

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1. Porting kernel 2.6.11.7 to S3C2410

???????http://superlp.blogchina.com/1391393.html

?????? 非常感谢此篇文档的作者

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2. devfs 介绍

???????http://www-128.ibm.com/developerworks/cn/linux/filesystem/l-fs4/index.html#resources

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3. <<BUILDING EMBEDDED LINUX SYSTEMS>>

??? 中文名：<<构建嵌入式Linux 系统>>