Thanks for your comment. Finally, i find out that i made a mistake. The uart(8250) have not been restore after resume, instead, it use the configuration got from boot. The uart have not been restored correctly, so that "ls" can not output result correctly resulting in it seems that the busybox can not work correctly. Now, i still have a question about the uart: why the "printk" can work correctly, but the "printf" not?
Before this, i believe that the "printk" work correctly, then the uart work ok. but now, i need more reconsidaration about the relation between the "printk", "printf" and "uart". Can anyone give me some suggestion? Any comment is welcome, thanks a lot.
在 2012年3月9日 下午10:08，Chenglie He chengjie.he@linaro.org写道：
Hi,
I am doing this on A9, echo mem >/sys/power/state is right, will trigger kernel to sleep.
-jack
some recipient promote: "The message contains HTML subpart, therefore we consider it SPAM or Outlook Virus" so i resend the email, hope it not disturb u. thanks a lot.