停在Freeing init memory: 92K，sys_open无法结束

(转)http://blog.sina.com.cn/s/blog_5592d0620100034s.html

在下载 2.6.15.4 的内核，
在[url]ftp://ftp.handhelds.org/projects/toolchain/arm-linux-gcc-3.4.1.tar.bz2[/url]下载交叉编译工具

修改Makefile
注释掉以下内容：
#ARCH ?= $(SUBARCH)
#CROSS_COMPILE ?=
增加如下内容：
ARCH : = arm
CROSS_COMPILE =/usr/local/arm/3.4.1/bin/arm-linux-

修改arch\arm\mach-s3c2410\devs.c文件

增加头文件定义
/***********add here***********/
#include

#include

#include

/**************end add********/

增加nand flash分区信息

/*****************************add here***************************/
static int chip0_map[] = { 0 };

struct mtd_partition s3c_nand_part[] = {
[0] = {
.name = "vivi",
.offset = 0x00000000,
.size = 0x00020000,
},
[1] = {
.name = "param",
.offset = 0x00020000,
.size = 0x00010000,
},
[2] = {
.name = "kernel",
.offset = 0x00030000,
.size = 0x001d0000,
},
[3] = {
.name = "root",
.offset = 0x00200000,
.size = 0x03dfc000,
}
};

static struct s3c2410_nand_set s3c_nand_sets[] = {
[0] = {
.name = "chip0",
.nr_chips = 1,
.nr_map = chip0_map,
.nr_partitions = ARRAY_SIZE(s3c_nand_part),
.partitions = s3c_nand_part
}
};

static struct s3c2410_platform_nand s3c_nand_info = {
.tacls = 0,
.twrph0 = 30,
.twrph1 = 0,
.nr_sets = ARRAY_SIZE(s3c_nand_sets),
.sets = s3c_nand_sets,
};

/********************************end add****************************/

struct platform_device s3c_device_nand = {
.name = "s3c2410-nand",
.id = -1,
.num_resources = ARRAY_SIZE(s3c_nand_resource),
.resource = s3c_nand_resource,
/***********add here****************/
.dev = {
.platform_data = &s3c_nand_info
}
/**************end here************/
};

可以交叉编译内核了
make mrproper //清楚所有config信息
make clean //清楚中间代码
make smdk2410_defconfig //使用默认2410配置
make menuconfig //配置
make


内核配置选择：


用NFS做根文件系统并配置网络：
主机上配置好NFS和DHCP服务
编译内核选择
Networking --->
[*] Networking support
Networking options --->
[*] IP: kernel level autoconfiguration
[*] IP: DHCP support
[*] IP: BOOTP support

File systems --->
Network File Systems --->
[*] NFS file system support
[*] Provide NFSv3 client support
[*] Provide client support for the NFSv3 ACL protocol extension
[*] Provide NFSv4 client support (EXPERIMENTAL)
[*] Allow direct I/O on NFS files (EXPERIMENTAL)
[ ] NFS server support
[*] Root file system on NFS

网卡驱动：
在下面的网址下载sunshiyou做好的dm9000x.c驱动

拷贝到drivers/net/arm目录下改名为dm9000.c

我这个开发板用的是EINT0,而2.6内核不能使用这个，所以把EINT0和EINT1焊到一起，驱动里面用的是EINT1。

修改drivers/net/arm/目录下的Kconfig文件，在最后添加如下内容：
Config ARM_DM9000
tristate "DM9000 for ARM support"
depends on NET_ETHERNET && ARM && ARCH_SMDK2410
help
Support for CS8900A chipset based Ethernet cards. If you have a network (Ethernet) 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.

修改drivers/net/arm/目录下的Makefile文件，在最后添加如下内容：
obj-$(CONFIG_ARM_DM9000) += dm9000.o

编译内核选择：
Device Drivers --->
Network device support --->
Ethernet (10 or 100Mbit) --->
[*] DM9000E suport for ARM

linux_cmd_line 配置为 noinitrd root=/dev/nfs nfsroot=192.168.1.130:/mnt/arm nfsaddrs=192.168.1.160 init=/linuxrc console=ttySAC0
在/mnt/arm目录放一个可用的文件系统（我是用cramfs文件解开的）

目前为止网卡已经驱动，并可以挂载上NFSROOT了但内核启动到释放内存就不动了，也没有出错信息。

内核启动到释放内存就不动了：
VFS: Mounted root (cramfs filesystem) readonly.
Freeing init memory: 92K

对内核代码init/main.c进行跟踪：
if (execute_command) {
printk("***********0\n" );
run_init_process(execute_command);
printk("***********2\n" );
printk(KERN_WARNING "Failed to execute %s. Attempting "
"defaults...\n", execute_command);
printk("***********3\n" );
}
printk("***********4\n" );
run_init_process("/sbin/init");
run_init_process("/etc/init");
run_init_process("/bin/init");
run_init_process("/bin/sh");
printk("***********5 \n");
panic("No init found. Try passing init= option to kernel.");

屏幕打印：
VFS: Mounted root (cramfs filesystem) readonly.
Freeing init memory: 92K
***********0

linux_cmd_line 去掉init=/linuxrc项，屏幕打印：

VFS: Mounted root (cramfs filesystem) readonly.
Freeing init memory: 92K
***********4


说明run_init_process函数 有问题

在网上一个maillist里看到解决方法：
Hi,

Kulkarni, Ganapatrao P. IN BLR SISL wrote:

[...]

> I am trying to boot the kernel, its comes up and hangs at the end
> (hangs after "Freeing init memory: 64K"), I am not getting the shell
> on the minicom.
>
> Anybody faced such problem??
> Any solution/workaround ... Please

If you have activated "FastFPE math emulation" im kernel config then try to use the "NWFPE math emulation" (section "General setup" in menuconfig).

I had the same problem a few weeks ago and solved it on this way (FastFPE seems to be not implemented).

[...]

Regards,
Wolfgang Schriebl

更改选项重新编译内核烧进板子重启：

mount: Mounting none on /root failed: Invalid argument
mount: Mounting none on /tmp failed: Invalid argument
mount: Mounting none on /var failed: Invalid argument
mkdir: Cannot create directory `/var/lib': Read-only file system
mkdir: Cannot create directory `/var/run': Read-only file system
mkdir: Cannot create directory `/var/log': Read-only file system

Please press Enter to activate this console.


BusyBox v1.00 (2006.01.11-14:20+0000) Built-in shell (ash)
Enter 'help' for a list of built-in commands.

-sh: can't access tty; job control turned off
id: unknown uid 0
[@(none) /]#

成功进入Shell。
上面的方法我没成功？？？？？？？？？？？？？
把[] Use the ARM EABI to compile the kernel选上可以，我是成功了