linux内核移植 I
根据tx2440的文档, 目标也比较简单, 先编译成功, 再烧录, 根文件系统, busybox 这些.
A. 准备
1. 解压tar, 修改根Makefile
ARCH ?= arm
CROSS_COMPILE ?= arm-linux-
2. 修改时钟
arch/arm/mach-s3c2440/mach-smdk2440.c
s3c24xx_init_clocks(12000000);
3. 修改机器码
arch/arm/tools/mach-types
s3c2440 .... xxx, 要对应uboot里面的机器码.
book@book-desktop:/tmp/linux-2.6.22.6/arch/arm/tools$ cat /tmp/u-boot/include/asm-arm/mach-types.h |grep S3C2440
#define MACH_TYPE_S3C2440 362
#define MACH_TYPE_SMDKS3C2440 782
#ifdef CONFIG_ARCH_S3C2440
# define machine_arch_type MACH_TYPE_S3C2440
# define machine_is_s3c2440() (machine_arch_type == MACH_TYPE_S3C2440)
book@book-desktop:/tmp/linux-2.6.22.6/arch/arm/tools$ cat mach-types |grep s3c2440
s3c2440 ARCH_S3C2440 S3C2440 362
似乎是对的, 暂时不管它.
4. 配置
make menuconfig
首先load一下2410的配置文件, 即arch/arm/configs/s3c2410_defconfig
进System Type, 选择S3C24xx Machine
仅选择以上几项, 其他不选.
然后save成.config文件.
5. make uImage, 是不是很简单...
烧进去看看吧.
6. 修改分区
arch/arm/plat-s3c24xx/common-smdk.c
[0] = {
.name = "BootLoader",
.size = 0x00040000,
.offset = 0,
},
[1] = {
.name = "params",
.offset = MTDPART_OFS_APPEND,
.size = 0x00020000,
},
[2] = {
.name = "kernel",
.offset = MTDPART_OFS_APPEND,
.size = 0x00200000,
},
[3] = {
.name = "root",
.offset = MTDPART_OFS_APPEND,
.size = MTDPART_SIZ_FULL,
}
内核启动的时候:
Creating 4 MTD partitions on "NAND 256MiB 3,3V 8-bit":
0x00000000-0x00040000 : "BootLoader" 0-0x40000是bootload分区, 大小是256K
0x00040000-0x00060000 : "params" 0x40000-0x60000是params分区, 128K
0x00060000-0x00260000 : "kernel" kernel分区有2M
0x00260000-0x10000000 : "root" 剩下的,到256M都是root分区.
bootargs=noinitrd console=ttySAC0 root=/dev/mtdblock3 rootfstype=yaffs
yaffs tragedy:attempt to put data chunk into a non-file
==>> yaffs bug: fs/yaffs2/yaffs_guts.c 3404
page 8826 in gc has no object: -65536 123600896 104202240
yaffs tragedy:attempt to put data chunk into a non-file
==>> yaffs bug: fs/yaffs2/yaffs_guts.c 3404
List of all partitions:
1f00 256 mtdblock0 (driver?)
1f01 128 mtdblock1 (driver?)
1f02 2048 mtdblock2 (driver?)
1f03 259712 mtdblock3 (driver?)
No filesystem could mount root, tried: yaffs
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(31,3)
搞了半天flash有问题..
能起来的情况下, uboot配置如下:
bootargs=noinitrd root=/dev/mtdblock3 init=/linuxrc console=ttySAC0
bootcmd=nand read.jffs2 0x30007FC0 kernel; bootm 0x30007FC0
bootdelay=2
baudrate=115200
ethaddr=08:00:3e:26:0a:5b
ipaddr=192.168.7.17
serverip=192.168.7.11
netmask=255.255.255.0
stdin=serial
stdout=serial
stderr=serial
mtdids=nand0=nandflash0
mtdparts=mtdparts=nandflash0:256k@0(bootloader),128k(params),2m(kernel),-(root)
partition=nand0,0
mtddevnum=0
mtddevname=bootloader
根目录设备挂载mnode
# ls -l
crw-r--r-- 1 0 0 5, 1 Jan 1 00:00 console
brw-r--r-- 1 0 0 31, 0 Jan 22 2008 mtdblock0
brw-r--r-- 1 0 0 31, 1 Jan 22 2008 mtdblock1
brw-r--r-- 1 0 0 31, 2 Jan 22 2008 mtdblock2
crw-r--r-- 1 0 0 1, 3 Jan 22 2008 null
crw-r--r-- 1 0 0 204, 64 Jan 1 00:04 ttySAC0
查看busybox依赖的库
book@book-desktop:/tmp/mini_fs/bin$ arm-linux-readelf -a "busybox"|grep Shared
0x00000001 (NEEDED) Shared library: [libcrypt.so.1]
0x00000001 (NEEDED) Shared library: [libm.so.6]
0x00000001 (NEEDED) Shared library: [libc.so.6]
最后烧录成jffs2文件格式,
启动参数改成:
bootargs=noinitrd root=/dev/mtdblock3 init=/linuxrc console=ttySAC0 rootfstype=jffs2
制作镜像文件的命令是:
mkfs.jffs2 -n -s 512 -e 16KiB -d mini_fs -o mini.jffs2