移植2.6.17.13到s3c2410

移植2.6.17.13到s3c2410

前一阵子移植了u-boot1.1.4之后，移植2.6.17.13走了一些弯路，采用了别人移植的2.6.14或2.6.11等方法都不成功，后来发现2.6.17比前几个版本的内核更容易。

从下载2.6.17.13.tar.bz2，解压：
#tar jxvf 2.6.17.13.tar.bz2

1、重新编译和修改u-boot
以前移植u-boot用的是arm-linux-gcc 2.95.3，到移植2.6内核的时候发现必须用gcc3.0以上的编译器，没办法只好下载了个arm-linux-gcc3.4.4 +glibc2.3.5，怕由于编译器不一致引起问题，重新编译了一次u-boot，没遇到任何错误。
2、修改内核顶层目录的Makefile，找到ARCH和CROSS_COMPILE的地方，修改为
ARCH ?= arm
CROSS_COMPILE ?= arm-linux-
保存。
3、 修改arch/arm/mach-s3c2410/common-smdk.c
设置Nand Flash的分区和信息，下面是我的分区结构：
static struct mtd_partition smdk_default_nand_part[] = {
[0] = {
.name = "bootloader",
.size = SZ_1M,
.offset = 0,
},
[1] = {
.name = "kernel",
.offset = SZ_1M,
.size = SZ_2M,
},如果您是在公共场合使用计算机，离开时
[2] = {
.name = "root",
.offset = SZ_1M*3,
.size = SZ_8M*5,
},
[3] = {
.name = "user",
.offset = SZ_1M*43,
.size = SZ_1M*21,
},
};
static struct s3c2410_platform_nand smdk_nand_info = {
.tacls = 0,
.twrph0 = 30,
.twrph1 = 0,
.nr_sets = ARRAY_SIZE(smdk_nand_sets),
.sets = smdk_nand_sets,
};

说明：这里2.6.17的设置分区与其他版本如2.6.14或2.6.11有点区别，其他版本是修改
arch/arm/machs3c2410/devs.c
和
arch/arm/machs3c2410/machsmdk2410.
2.6.17.13设置这些文件无效。

4、禁止Flash ECC校验
内核都是通过u-boot写数据到Nand Flash的, u-boot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，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。

5、支持启动时挂载devfs
为了我们的内核支持devfs以及在启动时并在/sbin/init运行之前能自动挂载/dev为devfs文件系统，修改fs/Kconfig文件，找到
menu "Pseudo filesystems"
添加如下语句：
config DEVFS_FS
bool "/dev file system support (OBSOLETE)"
default y
config DEVFS_MOUNT
bool "Automatically mount at boot"
default y
depends on DEVFS_FS
6、使用SMDK板子的config配置内核
#cp arch/arm/configs/smdk2410_defconfig .config
#make menuconfig
在smdk2410_defconfig的基础上，增加了下面选项：
Loadable module support >
[*] Enable loadable module support
[*] Automatic kernel module loading
System Type -->
[*] S3C2410 DMA support
Boot options -->
Default kernel command string:
noinitrd root=/dev/mtdblock2 init=/linuxrc console=ttySAC0,115200 mem=32M
#说明：mtdblock2代表第3个flash分区，用来作根文件系统rootfs；
# console=ttySAC0,115200使kernel启动期间的信息全部输出到串口0上，波特率为115200；
# 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
# mem=32M表示内存是32M，如果是64则设为64M
Floating point emulation -->
[*] NWFPE math emulation
#This is necessary to run most binaries!!!

#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 nonCFI AMD/JEDECcompatible 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
Character devices -->
[*] Nonstandard serial port support
[*] S3C2410 RTC Driver
USB Support -->
<*> Support for Host-side USB
MMC/SD Card Support -->
<*> MMC Support
<*> MMC block device driver
#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
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
保存退出，产生.config文件。

7、编译内核，下载到板子上
#make zImage
生成zImage在arch/arm/boot/目录下

zImage下载到板子上之后可以直接用go来执行，但是go启动内核的话会出现下面错误：
random2410 # tftp 30008000 2.6.17.13
TFTP from server 192.168.1.10; our IP address is 192.168.1.110
Filename '2.6.17.13'.
Load address: 0x30008000
Loading: #################################################################
#################################################################
#################################################################
########################
done
Bytes transferred = 1118644 (1111b4 hex)

random2410 # go 30008000
## Starting application at 0x30008000 ...
Uncompressing Linux.............................................................
Error: unrecognized/unsupported machine ID (r1 = 0x31f07d30).

Available machine support:

ID (hex) NAME
000000c1 SMDK2410

Please check your kernel config and/or bootloader.

产生的原因是go启动内核的话，u-boot不会传machiine ID给内核，因为go只是执行普通的应用程序，不考虑到传递参数给内核的问题，没有必要在乎它。如果只是想看看go能不能启动内核的话，修改方法有两个：
a、修改u-boot的common/cmd_boot.c的do_go()函数：
/*#if defined(CONFIG_I386)*/ <==注释掉
DECLARE_GLOBAL_DATA_PTR;
/*#endif*/ <==注释掉
....
#if !defined(CONFIG_NIOS)

/*******************add here*******************************/
if(argc==2)
rc = ((ulong (*)(int, char *[]))addr) (0, gd->bd->bi_arch_number);
else
/*********************add end *****************************/
rc = ((ulong (*)(int, char *[]))addr) (--argc, &argv[1]);

b、修改内核的arch/arm/kernel/head.S，直接将s3c2410的参数赋给内核
__INIT
.type stext, %function
ENTRY(stext)
/****************add here*****************/
mov r0, #0
mov r1, #0xc1
ldr r2, =0x30000100
/***************end add******************/
msr cpsr_c, #PSR_F_BIT | PSR_I_BIT | MODE_SVC @ ensure svc mode
@ and irqs disabled
8、用bootm启动内核
这个方法u-boot可以将machine ID传给内核，正常启动，不过用u-boot的mkimage工具（在u-boot1.1.4/tools/目录下）将前面生成的zImage加上一个信息头（有关如何添加头的命令和使用tftp在后面讲述），之后下载到板子上，启动控制台信息如下：

U-Boot 1.1.4 (Sep 20 2006 - 00:34:30)

U-Boot code: 31F80000 -> 31F9628C BSS: -> 31F9A578
RAM Configuration:
Bank #0: 30000000 32 MB
Flash: 512 kB
*** Warning - bad CRC, using default environment

In: serial
Out: serial
Err: serial
random2410 # tftp 30008000 uImage2.6.17.13
TFTP from server 192.168.1.10; our IP address is 192.168.1.110
Filename 'uImage2.6.17.13'.
Load address: 0x30008000
Loading: #################################################################
#################################################################
#################################################################
########################
done
Bytes transferred = 1116720 (110a30 hex)
random2410 # bootm 30008000
## Booting image at 30008000 ...
Image Name: linux-2.6.17.13
Created: 2006-09-19 17:25:57 UTC
Image Type: ARM Linux Kernel Image (uncompressed)
Data Size: 1116656 Bytes = 1.1 MB
Load Address: 30008000
Entry Point: 30008040
Verifying Checksum ... OK
XIP Kernel Image ... OK

Starting kernel ...

cleanup before linux...
enter the Kerne....address is 30008040
transfer params to linux kernel:
machine ID: r1=c1, boot params addr: r2=30000100
enter decompress_kernel...
finished to arch_decomp_setup
Uncompressing Linux......................................................................... done, booting the kernel.
Linux version 2.6.17.13 (xzs@xzs-pc) (gcc version 3.4.4) #7 Wed Sep 20 01:23:13 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, associativity 64, 32 byte lines, 8 sets
Built 1 zonelists
Kernel command line: noinitrd root=/dev/mtdblock2 init=/linuxrc console=ttySAC0,115200 mem=32M
irq: clearing pending ext status 00000200
irq: clearing subpending status 00000002
PID hash table entries: 256 (order: 8, 1024 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: 32MB = 32MB total
Memory: 30080KB available (1856K code, 404K data, 92K init)
Mount-cache hash table entries: 512
CPU: Testing write buffer coherency: ok
NET: Registered protocol family 16
S3C2410: Initialising architecture
usbcore: registered new driver usbfs
usbcore: registered new driver hub
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: 512 (order: -1, 2048 bytes)
TCP: Hash tables configured (established 1024 bind 512)
TCP reno registered
S3C2410 DMA Driver, (c) 2003-2004 Simtec Electronics
DMA channel 0 at c2800000, irq 33
DMA channel 1 at c2800040, irq 34
DMA channel 2 at c2800080, irq 35
DMA channel 3 at c28000c0, irq 36
NetWinder Floating Point Emulator V0.97 (double precision)
JFFS2 version 2.2. (NAND) (C) 2001-2003 Red Hat, Inc.
io scheduler noop registered
io scheduler anticipatory registered (default)
io scheduler deadline registered
io scheduler cfq registered
Console: switching to colour frame buffer device 80x25
fb0: Virtual frame buffer device, using 1024K of video memory
S3C2410 RTC, (c) 2004 Simtec Electronics
s3c2410-uart.0: s3c2410_serial0 at MMIO 0x50000000 (irq = 70) is a S3C2410
s3c2410-uart.1: s3c2410_serial1 at MMIO 0x50004000 (irq = 73) is a S3C2410
s3c2410-uart.2: s3c2410_serial2 at MMIO 0x50008000 (irq = 76) is a S3C2410
RAMDISK driver initialized: 16 RAM disks of 4096K size 1024 blocksize
S3C24XX NAND Driver, (c) 2004 Simtec Electronics
s3c2410-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)
NAND_ECC_NONE selected by board driver. This is not recommended !!
Scanning device for bad blocks
Bad eraseblock 629 at 0x009d4000
Creating 4 MTD partitions on "NAND 64MiB 3,3V 8-bit":
0x00000000-0x00100000 : "bootloader"
mtd: Giving out device 0 to bootloader
0x00100000-0x00300000 : "kernel"
mtd: Giving out device 1 to kernel
0x00300000-0x02b00000 : "root"
mtd: Giving out device 2 to root
0x02b00000-0x04000000 : "user"
mtd: Giving out device 3 to user
usbmon: debugfs is not available
mice: PS/2 mouse device common for all mice
ts: Compaq touchscreen protocol output
TCP bic registered
NET: Registered protocol family 1
Reading data from NAND FLASH without ECC is not recommended
No filesystem could mount root, tried: cramfs romfs
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(31,2)

这里因为我没有添加任何应用程序和文件系统，所以出错，不影响内核已经成功移植。

9、使用mkimage给zImage添加信息头
mkimage -A arm -O linux -T kernel -C none -a 30008000 -e 30008040 -n linux-2.6.17.13 -d zImage uImage2.6.17.13
-A arm -------- 架构是arm
-O linux -------- 操作系统是linux
-T kernel -------- 类型是kernel
-C none -------- 压缩类型为无压缩
-a 30008000 ---- image的载入地址(hex)
-e 30008040 ---- 内核的入口地址(hex)，因为信息头的大小是0x40
-n linux-2.6.17.13 --- image的名字
-d zImage ---- 无头信息的image文件名
uImage2.6.17.13 ---- 加了头信息之后的image文件名

10、使用tftp下载内核
a、安装atftpd
我现在用的linux是ubuntu6.06，安装了atftpd，没安装的话使用
#sudo apt-get install atftpd
安装。
b、接着建立/tftp目录，并设置所有人都有读写运行权限：
#sudo mkdir /tftp
#sudo chmod 777 tftp

c、启动tftp服务：
#sudo atftpd --daemon --user xzs --group root /tftp

d、将zImage和uImage2.6.17.13复制到/tftp目录下

e、启动minicom，复位板子，在minicom下输入
tftp 30008000 uImage2.6.17.13
如果已经板子和PC机已经通过网线连接，IP也正确，则会出现一下信息：
TFTP from server 192.168.1.10; our IP address is 192.168.1.110
Filename 'uImage2.6.17.13'.
Load address: 0x30008000
Loading: #################################################################
#################################################################
#################################################################
########################
done
Bytes transferred = 1116720 (110a30 hex)