Dear Shawn Guo,
In message 20110226173040.GD2672@S2100-06.ap.freescale.net you wrote:
I'm still a little bit new to dt. I thought the bootargs in chosen node will always apply when dt is enabled. It just took me some time to figure out that u-boot 'bootargs' env will anyway overwrite the one from chosen.
This is not quite correct. U-Boot will not always overwrite the settings from "chosen", but only if you provide any "better" settings by defining the "bootargs" environment variable.
str = getenv("bootargs"); if (str != NULL) {
...
The 'force' is hard-coded as 1, so it always overwrites. Knowing that may save your some time, if you are green hands as me ;)
If you don't want to use the U-Boot settings, then just don't define any. If you bother to define such data, it is assumed that you actually want to see it used.
Best regards,
Wolfgang Denk