TE2410移植linux-2.6.14及调试过程总结(2)
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plat->tacls:0
本文引用地址：https://www.eepw.com.cn/article/201611/317263.htmplat->twrph0:3
plat->twrph1:0
tacls:1
twrph0:1
twrph1:1
clkrate:100000000/*注意是8个0,实际就是是HCLK=100MHz*/
#define NS_IN_KHZ 10000000/*注意是7个0*/
static int s3c2410_nand_calc_rate(int wanted, unsigned long clk, int max)
{
int result;
result = (wanted * NS_IN_KHZ) / clk;
result++;
pr_debug("result %d from %ld, %dn", result, clk, wanted);
if (result > max) {
printk("%d ns is too big for current clock rate %ldn",
wanted, clk);
return -1;
}
if (result < 1)
result = 1;
return result;
}
s3c2410_nand_calc_rate(plat->twrph0, clkrate, 8)
即s3c2410_nand_calc_rate(3, 100000000, 8)
则wanted=3, clk=100000000,max=8
result = (wanted * NS_IN_KHZ) / clk
result =(3 * 10000000)/100000000显然结果为0,result++;后返回值为1
按照这个函数的本意应该是要返回4的,如果要修改的话,将它的值NS_IN_KHZ改为与HCLK相同的值,就可以了,我本来想改为100000000,想想如果uboot的FCLK改成202.8MHz,那么HCLK值为101.4MHz,则clkrate为101400000
result = (wanted * NS_IN_KHZ) / clk=(3 * 100000000)/101400000=0
还是不行啊,真该死,终于找到原因了,原来linux源码是没有问题的,在
linux-2.6.14linux-2.6.14archarmmach-s3c2410devs.c中
struct s3c2410_platform_nandsuperlpplatform={
tacls:0,
twrph0:30,/*原来写的是3*/
twrph1:0,
sets:&nandset,
nr_sets:1,
};
串口打印出来内容如下:
plat->tacls:0
plat->twrph0:30
plat->twrph1:0
tacls:1
twrph0:3
twrph1:1
clkrate:101400000
s3c2410-nand: timing: Tacls 10ns, Twrph0 30ns, Twrph1 10ns
5.Reading da
VFS: Mounted root (cramfs filesystem) readonly.
Freeing init memory: 92K
Warning: unable to open an initial console.
Reading da
sd_mod: version magic 2.6.8.1-ptx1 ARMv4 gcc-3.3 should be 2.6.14 ARMv4 gcc-3.4
usb_storage: version magic 2.6.8.1-ptx1 ARMv4 gcc-3.3 should be 2.6.14 ARMv4 gcc-3.4
usbvideo: version magic 2.6.8.1-ptx1 ARMv4 gcc-3.3 should be 2.6.14 ARMv4 gcc-3.4
ov511: version magic 2.6.8.1-ptx1 ARMv4 gcc-3.3 should be 2.6.14 ARMv4 gcc-3.4
说明一下:之前并没有碰到这个问题,写总结时故意去掉对devfs的支持,出现这样的错误
Warning: unable to open an initial console.
原因是文件系统的dev目录下没有console节点,解决办法有2个,
(1)制作文件系统时在dev目录下建立console节点
(2)make menuconfig时加上对devfs的支持,就可以正常启动
加上对devfs的支持,系统会根据需要自动创建所需节点
用ramdisk作根文件系统:
(1)make menuconfig时要选择支持ext2文件系统，因为ramdisk大多用ext2;
(2)make menuconfig时要选择RAM disk support
(3)make menuconfig时还要选择初始化ramdisk(initrd)
DeviceDrivers ->
Block Device->
<*>RAM disk support
[*]Initial RAM disk(initrd)support
(4)make menuconfig时还要设置好RAM disk的大小
DeviceDrivers ->
Block Device->
<*>RAM disk support
(16)Default number of RAM disks
(4096)Default RAM disk size(kbytes)
加载ramdisk时出现如下问题：
RAMDISK driver initialized:16RAM disks of4096Ksize 1024 blocksize
RAMDISK: Compressed image found at block 0
RAMDISK: incomplete write (-28 != 32768) 4194304
fs_names=ext2
root_mount_da
VFS: Mounted root (ext2 filesystem).
Mounted devfs on /dev
Freeing init memory: 92K
attempt to access beyond end of device
ram0: rw=0, want=16518, limit=8192
EXT2-fs error (device ram0): ext2_get_inode: unable to read inode block - inode=1944, block=8258
Failed to execute /linuxrc.Attempting defaults...
attempt to access beyond end of device
ram0: rw=0, want=16514, limit=8192
EXT2-fs error (device ram0): ext2_get_inode: unable to read inode block - inode=1922, block=8256
Kernel panic - not syncing: No init found.Try passing init= option to kernel.
解决办法：修改内核关于Ramdisk的设置
make menuconfig
DeviceDrivers ->
Block Device->
<*>RAM disk support
(16)Default number of RAM disks16改为8
(4096)Default RAM disk size(kbytes)4096改为8192
板子的SDRAM是64M,16*4096kB = 8*8192kB = 64M
问题依然：
RAMDISK driver initialized:8RAM disks of8192K size 1024 blocksize
Mounted devfs on /dev
Freeing init memory: 92K
attempt to access beyond end of device
ram0: rw=0, want=16518, limit=16384
EXT2-fs error (device ram0): ext2_get_inode: unable to read inode block - inode=1944, block=8258
Failed to execute /linuxrc.Attempting defaults...
attempt to access beyond end of device
ram0: rw=0, want=16514, limit=16384
EXT2-fs error (device ram0): ext2_get_inode: unable to read inode block - inode=1922, block=8256
Kernel panic - not syncing: No init found.Try passing init= option to kernel.
修改
Default number of RAM disks值改为4
Default RAM disk size(kbytes)值改为16384
问题解决
为什么是16384呢?16384kb=16M,我制作的ramdisk镜像大小为15M,这里的15M是未用gzip压缩前的大小.
另外关于commandline的值:initrd=0x30800040,0x400000 root=/dev/ram init=/linuxrc console=ttySAC0
initrd=0x30800040是ramdisk在SDRAM中的地址,我用mkimage将ramdisk加了64(0x40)字节头信息,制作成uboot可以识别的uRamdisk,然后下载到0x30800000,所以ramdisk的正真地址为0x30800040
0x400000(4M)为ramdisk的大小,要大于压缩后的大小,我制作好的ramdisk大小为15M，压缩后1.2M
root=/dev/ram也可以是root=/dev/ram0
我在nand flash的第四个分区下载了cramfs文件系统,可以通过mount命令挂载该分区到tmp目录下
# cd dev
# ls
consolekmemmmcptmxrdttyvcc
fbkmsgmtdblockptsrooturandomzero
fullmemnullptyshmusb
inputmiscportrandomttsvc
#mount /dev/mtdblock/3/tmp
另一种方法可以在系统启动时就挂载该分区
修改/etc/init.d/rcS文件
内容如下(蓝色字体为添加的内容):
#!/bin/sh
echo "mount cramfs from mtdblock/3"
/bin/mount /dev/mtdblock/3/tmp
echo "mount all"
/bin/mount –a
说明:/etc/init.d/rcS是可执行的二进制文件,系统启动时被执行
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