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分类： 嵌入式
2015-06-10 22:03:44
原文地址：移植内核之nandflash驱动 作者：linux_cjok
1 机器码
为自己的开发板设定一个机器码，添加在/arch/arm/tools/mach_types文件中
ut6410 MACH_UT6410 UT6410 1626
可以说随便设为什么数字，但是一定要和你uboot的 include/asm-arm/mach-types.h设定
的机器码匹配
2 复制 mach-s3c6410.c
Cp mach-s3c6410.c mach-ut6410.c
Mach-ut6410.c要修改的地方很多，会在后面详细讲解。
3 修改arch/arm/mach-s3c6410/下的Kconfig、Makefile
Vim Kconfig 加入配置选项：
config MACH_UT6410
bool "UT6410"
select CPU_S3C6410
select S3C_DEV_HSMMC
select S3C_DEV_HSMMC1
select S3C_DEV_I2C1
select S3C_DEV_FB
select S3C_DEV_USB_HOST
select S3C_DEV_USB_HSOTG
select S3C6410_SETUP_SDHCI
select S3C64XX_SETUP_I2C1
select S3C64XX_SETUP_FB_24BPP
help
Machine support for the UT6410, Modified by CJOK
Vim Makefile 加入：
obj-$(CONFIG_MACH_UT6410) += mach-ut6410.o
4 复制配置文件
Cp arch/arm/config/s3c6400_defconfig .config
如果找不到本芯片的配置文件，就找与本芯片型号相近的配置文件
*****配置文件不对，在编译的时候可能会出现error！
5 修改mach-ut6410.c
Vim mach-ut6410.c
在vim命令行输入：
：%s/smdk6410/ut6410/g
作用是把smdk6410全部替换为ut6410
6 在mach-ut6410.c加入nandflash分区信息以及驱动
加入必要的头文件
> #include
> #include
> #include
> #include
> #include
加入分区信息
> /* modified by CJOK */
> static struct mtd_partition ut6410_default_nand_part[] __initdata = {
> [0] = {
> .name = "u-boot",
> .size = 0x40000,
> .offset = 0,
> },
> [1] = {
> .name = "kernel",
> .size = 0x3c0000,
> .offset = 0x40000,
> },
> [2] = {
> .name = "rootfs",
> .size = 0x5000000,
> .offset = 0x400000,
> },
> [3] = {
> .name = "file system",
> .size = 0xac00000,
> .offset = 0x5400000,
> },
> };
>
> static struct s3c2410_nand_set ut6410_nand_sets[] __initdata = {
> [0] = {
> .name = "nand",
> .nr_chips = 1,
> .nr_partitions = ARRAY_SIZE(ut6410_default_nand_part),
> .partitions = ut6410_default_nand_part,
> .flash_bbt = 1, /* we use u-boot to create a BBT */
> },
> };
>
> static struct s3c2410_platform_nand ut6410_nand_info __initdata = {
> .tacls = 25,
> .twrph0 = 55,
> .twrph1 = 40,
> .nr_sets = ARRAY_SIZE(ut6410_nand_sets),
> .sets = ut6410_nand_sets,
> .ignore_unset_ecc = 1,
> };
Tacls,twrph0,twrph1是根据S3C6410资料得到，具体怎么得来的，还望高手能指点，
上面的数据是参考网友的。
在结构体static struct platform_device *ut6410_devices[] __initdata 中加入
&s3c_device_nand,
在函数static void __init ut6410_map_io(void)中加入
s3c_device_nand.dev.platform_data = &ut6410_nand_info;
在函数static void __init ut6410_machine_init(void)中加入
s3c_fb_set_platdata(&ut6410_nand_info);
修改：> MACHINE_START(UT6410, "UT6410 modified by CJOK")
基本上nandflash就只要添加这么多信息
7 配置内核
Make menuconfig ARCH=arm CROSS_COMPILE=arm-linux-
添加对nandflash的支持：
Device Drivers --->
<*> Memory Technology Device (MTD) support --->
[*] MTD partitioning support
<*> NAND Device Support --->
<*> NAND Flash support for Samsung S3C SoCs
<*> Caching block device access to MTD devices
添加对NFS支持
[*] Networking support --->
Networking options --->
[*] TCP/IP networking
[*] IP: kernel level autoconfiguration
选上自己配置的芯片类型
System Type --->
[*] UT6410
是不是觉得很眼熟，对，就是我们刚刚第3步修改Kconfig得到的
8编译烧写到开发板上
Make zImage CROSS_COMPILE=arm-linux- ARCH=arm
启动信息：
………………………………………………………………………………………….
Creating 4 MTD partitions on "NAND 256MiB 3,3V 8-bit":
0x000000000000-0x000000040000 : "u-boot"
0x000000040000-0x000000400000 : "kernel"
0x000000400000-0x000005400000 : "rootfs"
0x000005400000-0x000010000000 : "file system"
mice: PS/2 mouse device common for all mice
i2c /dev entries driver
sdhci: Secure Digital Host Controller Interface driver
sdhci: Copyright(c) Pierre Ossman
TCP cubic registered
VFP support v0.3: implementor 41 architecture 1 part 20 variant b rev 5
VFS: Cannot open root device "mtdblock2" or unknown-block(31,2)
Please append a correct "root=" boot option; here are the available partitions:
1f00 256 mtdblock0 (driver?)
1f01 3840 mtdblock1 (driver?)
1f02 81920 mtdblock2 (driver?)
1f03 176128 mtdblock3 (driver?)
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(31,2)
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额，出现了KERNEL PANIC，不要紧张
有三种情况：
a MTD分区与bootloader不匹配
b 没有devfs文件系统支持
c ECC校验没有关闭
终于看到了分区信息，nandflash驱动OK
可能遇到的问题：
问题一：
下载到板子上，发现如下问题，此问题郁闷我最久，
…………………………………..
CPU: Testing write buffer coherency: ok
s3c6400-nand: failed to claim resource 0
WARNING: at drivers/base/core.c:130 device_release+0x70/0x84()
…………………………………………………….
------------[ cut here ]------------
WARNING: at drivers/base/core.c:130 device_release+0x70/0x84()
Device 's3c64xx-rtc' does not have a release() function, it is broken and must be fixed.
Modules linked in:
……………………………………………………….
解决方法就是修改arch./arm/plat-samsung/dev-nand.c 中的
static struct resource s3c_nand_resource[] = {
[0] = {
.start = S3C_PA_NAND,
.end = S3C_PA_NAND + SZ_1M -1,
.flags = IORESOURCE_MEM,
}
};
.end = S3C_PA_NAND + SZ_1M-1, 减去一就行了
问题二：
……………………………………………………..
end_request: I/O error, dev mtdblock2, sector 16
Buffer I/O error on device mtdblock2, logical block 2
uncorrectable error :
uncorrectable error :
end_request: I/O error, dev mtdblock2, sector 24
Buffer I/O error on device mtdblock2, logical block 3
uncorrectable error :
uncorrectable error :
end_request: I/O error, dev mtdblock2, sector 24
Buffer I/O error on device mtdblock2, logical block 3
List of all partitions:
1f00 256 mtdblock0 (driver?)
1f01 3840 mtdblock1 (driver?)
1f02 81920 mtdblock2 (driver?)
1f03 176128 mtdblock3 (driver?)
No filesystem could mount root, tried: cramfs
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(31,2)
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解决办法：
1、drivers/mtd/nand/s3c2410.c的函数s3c2410_nand_init_chip中的
NAND_ECC_SOFT修改为NAND_ECC_NONE
2、配置内核时，不要选上NAND ECC
