固化固化RAMDISK到NAND FLASH中： "upsafefs=" "tftp 30008000 safefs.img;" \
"nand erase clean 00400000 $filesize;" \
"nand write.jffs2 30008000 00400000 $filesize\0" \
其实不用固化RANDISK到ＮＡＮＤ中，直接从U盘加载即可。
加载从NAND FLASH加载RAMDISK：
到RAM中，地址为0x31800000，大小16M
nand read.jffs2 31800000 00400000 1000000
从U盘加载RAMDISK：
usb start
setenv dev 0:1
fatload usb $dev 0x31800000 ramdisk.img 或者 fatload usb 0:1 0x31800000 ramdisk.img
参数U-Boot启动参数：
setenv bootargs "root=/dev/ram rw initrd=0x31800000,16M console=tty0 console=ttySAC0,115200"
进入安全模式首先输入命令，进行启动参数设置 ： U-Boot$ setenv bootargs "root=/dev/ram rw initrd=0x31800000,16M console=ttySAC0,115200" 然后输入加载ramdisk和加载内核并启动的命令： U-Boot$ run loadramdisk;run yboot 奇怪的是，如果将设置参数的命令和加载RAM盘以及内核的命令合成一条命令，会出现错误（红色标志） Starting kernel ... Uncompressing Linux................................................................................................................................. done, booting the kernel. Linux version 2.6.28 (root@localhost.localdomain) (gcc version 3.4.1) #117 Wed Mar 11 13:02:33 CST 2009 CPU: ARM920T [41129200] revision 0 (ARMv4T), cr=c0007177 CPU: VIVT data cache, VIVT instruction cache Machine: ABING2440 Memory policy: ECC disabled, Data cache writeback INITRD: 0x31800000+0x04000000 extends beyond physical memory - disabling initrd CPU S3C2440A (id 0x32440001) ......
yaffs: dev is 1048576 name is "ram0"
yaffs: passed flags ""
yaffs: Attempting MTD mount on 1.0, "ram0"
yaffs: dev is 1048576 name is "ram0"
yaffs: passed flags ""
yaffs: Attempting MTD mount on 1.0, "ram0"
List of all partitions:
1f00 32768 mtdblock0 (driver?)
1f01 225280 mtdblock1 (driver?)
No filesystem could mount root, tried: ext2 vfat msdos iso9660 yaffs yaffs2
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(1,0)
出错信息是从文件arch/arm/mm/init.c里面打印出来的，从错误信息来看，应该是phys_initrd_size的值传递错了，传递为实际RAM的大小了，本应该是radisk的大小的。
文件：arch/arm/mm/init.c static int __init check_initrd(struct meminfo *mi)
{
int initrd_node = -2;
#ifdef CONFIG_BLK_DEV_INITRD
unsigned long end = phys_initrd_start + phys_initrd_size;
/*
* Make sure that the initrd is within a valid area of
* memory.
*/
if (phys_initrd_size) {
unsigned int i;
initrd_node = -1;
for (i = 0; i < mi->nr_banks; i++) {
struct membank *bank = &mi->bank[i];
if (bank_phys_start(bank) <= phys_initrd_start &&
end <= bank_phys_end(bank))
initrd_node = bank->node;
}
}
if (initrd_node == -1) {
printk(KERN_ERR "INITRD: 0x%08lx+0x%08lx extends beyond "
"physical memory - disabling initrd\n",
phys_initrd_start, phys_initrd_size);
phys_initrd_start = phys_initrd_size = 0;
}
#endif
return initrd_node;
} 最后发现是默认命令的RAMDISK大小写错了，应该是16M的，却写成了64M。 |