In message 50c9a2250601221806ifdd8f49n92ce779250ef4ff1@mail.gmail.com you wrote:
my board has mips 4kec core. and my kernel is montavista linux. when i use the command bootm kernel_addr ramdisk_addr, it can't find ramdisk. but if i download the ramdisk.gz to sdram, and pass the command line initrd=ramdisk_addr, it can bootm correctly. i wonder if kernel receiving the env param of initrd_start passed by bootm is a common feature for all arch, or special for some arch?
As far as U-Boot is concerned please check "lib_mips/mips_linux.c" to see how it uses linux_env_set() to pass parameters like "memsize", "initrd_start", "initrd_size" etc.
You will have to check within your kernel source tree how they pick up this information (and eventually ask MV support instead of this list ;-)
Best regards,
Wolfgang Denk