移植linux-3.0.62 + busybox最小系统到单板TQ2440

玩了一段时间裸板开发，u-boot也移植好了，现在开始专注驱动开发，首先把linux最小系统搭建起来，移植网卡驱动，用NFS挂载文件系统，再完善其它驱动。

开发环境：
系统：ubuntu 10.04.4
单板：tq2440
NAND FLASH：K9F1216U0A 256MB
NOR Flash：EN29LV160AB 2MB
SDRAM：HY57V561620 x2 64MB
NET：DM9000AEP
编译器：arm-none-linux-gnueabi-

搭建开发环境详见ubuntu 10.04.4开发环境配置。
目标：
1.移植linux-3.0.62到单板，串口正常输出内核启动信息
2.移植网卡驱动
3.busybox制作最小文件系统
4.NFS挂载文件系统

一、移植linux-3.0.62到单板，串口正常输出内核启动信息

1.下载源码

linux源码https://www.kernel.org/pub/linux/kernel/v3.0/ 下载linux-3.0.62.tar.bz2。

获取交叉编译链 http://code.google.com/p/smp-on-qemu/downloads/list 选择arm-2009q3-67-arm-none-linux-gnueabi-i686-pc-linux-gnu.tar.bz2并下载。然后在ubuntu下直接解压即可

2.配置、编译

首先修改根目录下Makefile:195

ARCH  ?= $(SUBARCH)
CROSS_COMPILE ?= $(CONFIG_CROSS_COMPILE:"%"=%)

改为：其中/home/change/tools/arm-2009q3是我的解压路径

ARCH  ?= arm
CROSS_COMPILE ?= /home/change/tools/arm-2009q3/bin/arm-none-linux-gnueabi-

change@change:~/Si/linux-3.0.62$ make s3c2410_defconfig

change@change:~/Si/linux-3.0.62$ make uImage

编译成功，烧写内核到单板，启动会提示machid error,Please check your kernel config and/or bootloader.并且供支持单板的id，其中0000016a   SMDK2440，OK设置id

U-Boot 2012.04.01 (May 04 2013 - 15:32:54)

CPUID: 32440001
FCLK:      400 MHz
HCLK:      100 MHz
PCLK:       50 MHz
DRAM:  64 MiB
WARNING: Caches not enabled
Flash: 2 MiB
NAND:  256 MiB
In:    serial
Out:   serial
Err:   serial
Net:   dm9000
Hit any key to stop autoboot:  0
TQ2440 # mtdpart

device nand0 <TQ2440-0>, # parts = 4
 #: name                size            offset          mask_flags
 0: u-boot              0x00040000      0x00000000      0
 1: params              0x00020000      0x00040000      0
 2: kernel              0x00400000      0x00060000      0
 3: rootfs              0x0fba0000      0x00460000      0

active partition: nand0,0 - (u-boot) 0x00040000 @ 0x00000000

defaults:
mtdids  : nand0=TQ2440-0
mtdparts: mtdparts=TQ2440-0:256k(u-boot),128k(params),4M(kernel),-(rootfs)
TQ2440 # tftp 0x32000000 uImage
dm9000 i/o: 0x20000000, id: 0x90000a46
DM9000: running in 16 bit mode
MAC: 00:0c:29:4d:e4:f4
could not establish link
Using dm9000 device
TFTP from server 172.16.1.132; our IP address is 172.16.1.111
Filename 'uImage'.
Load address: 0x32000000
Loading: #################################################################
         #################################################################
         ###########################
done
Bytes transferred = 2297920 (231040 hex)
TQ2440 # nand erase.part kernel

NAND erase.part: device 0 offset 0x60000, size 0x400000
Erasing at 0x440000 -- 100% complete.
OK
TQ2440 # nand write 0x32000000 kernel

NAND write: device 0 offset 0x60000, size 0x400000
 4194304 bytes written: OK
TQ2440 # set machid 16a

TQ2440 # boot

NAND read: device 0 offset 0x60000, size 0x400000
 4194304 bytes read: OK
## Booting kernel from Legacy Image at 30000000 ...
   Image Name:   Linux-3.0.62
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    2297856 Bytes = 2.2 MiB
   Load Address: 30108000
   Entry Point:  30108000
   Verifying Checksum ... OK
   Loading Kernel Image ... OK
OK
Using machid 0x16a from environment

Starting kernel ...

Uncompressing Linux... done, booting the kernel.
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下面修改源码，新建Source Insight工程。看到编译的uImage这么大，顺便把我的u-boot分区kernel分大了点。出现乱码应该时钟问题。配置文件*_defconfig在arch/arm/configs，machid在include/generated/mach-types.h.修改arch/arm/mach-s3c2440/mach-smdk2440.c:163:

s3c24xx_init_clocks(16934400);改为s3c24xx_init_clocks(12000000);//TQ2440单板的晶振是12M

再次配置编译生成的uImage就能正常输出启动信息了。

二、修改单板源码

1.增加NAND分区

修改arch/arm/pla-s3c24xxt/common-smdk.c.根据以前u-boot分区修改，将NAND分区改为如下

/* NAND parititon from 2.4.18-swl5 */

static struct mtd_partition smdk_default_nand_part[] = {
 [0] = {
  .name = "u-boot",
  .size = SZ_256K,
  .offset = 0,
 },
 [1] = {
  .name = "u-boot-env",
  .offset = SZ_256K,
  .size = SZ_128K,
 },
 [2] = {
  .name = "kernel",
  .offset = SZ_256K + SZ_128K,
  .size = SZ_4M,
 },
 [3] = {
  .name = "rootfs",
  .offset = SZ_256K + SZ_128K + SZ_4M,
  .size = MTDPART_SIZ_FULL,
 }
};

2.DM9000支持

其实现在linux内核自带DM9000网卡驱动，我们只需要配置即可，谈不上什么移植，参考别人代码修改eg:mach-mini2440.c。修改arch/arm/mach-s3c2440/mach-smdk2440.c.从mach-mini2440.c拷贝DM9000部分程序，并修改为TQ2440.

#include <linux/dm9000.h>

#define MACH_TQ2440_DM9K_BASE (S3C2410_CS4 + 0x300)
/* DM9000AEP 10/100 ethernet controller */

static struct resource TQ2440_dm9k_resource[] = {
 [0] = {
  .start = MACH_TQ2440_DM9K_BASE,
  .end   = MACH_TQ2440_DM9K_BASE + 3,
  .flags = IORESOURCE_MEM
 },
 [1] = {
  .start = MACH_TQ2440_DM9K_BASE + 4,
  .end   = MACH_TQ2440_DM9K_BASE + 7,
  .flags = IORESOURCE_MEM
 },
 [2] = {
  .start = IRQ_EINT7,
  .end   = IRQ_EINT7,
  .flags = IORESOURCE_IRQ | IORESOURCE_IRQ_HIGHEDGE,
 }
};

/*
 * The DM9000 has no eeprom, and it's MAC address is set by
 * the bootloader before starting the kernel.
 */
static struct dm9000_plat_data TQ2440_dm9k_pdata = {
 .flags  = (DM9000_PLATF_16BITONLY | DM9000_PLATF_NO_EEPROM),
};

static struct platform_device TQ2440_device_eth = {
 .name  = "dm9000",
 .id  = -1,
 .num_resources = ARRAY_SIZE(TQ2440_dm9k_resource),
 .resource = TQ2440_dm9k_resource,
 .dev  = {
  .platform_data = &TQ2440_dm9k_pdata,
 },
};

再将&TQ2440_device_eth,添加到static struct platform_device *smdk2440_devices[]

static struct platform_device *smdk2440_devices[] __initdata = {
 &s3c_device_ohci,
 &s3c_device_lcd,
 &s3c_device_wdt,
 &s3c_device_i2c0,
 &s3c_device_iis,
 &TQ2440_device_eth,
 &s3c_device_nand,
};

开始编译，有问题再修改。make menuconfig 看到默认配置是支持DM9000的

change@change:~/Si/linux-3.0.62$ make uImage

编译成功，烧到NAND，内核启动输出如下

NAND read: device 0 offset 0x60000, size 0x400000
 4194304 bytes read: OK
## Booting kernel from Legacy Image at 30000000 ...
   Image Name:   Linux-3.0.62
   Image Type:   ARM