Yes!... this is a embedded system, and will not have monitor. So, serial is the default console.
I pass cmdline as "root=/dev/ram rw console=ttyS0,115200" Thanks Siva -----Original Message----- From: Scott Russell [mailto:[EMAIL PROTECTED] Sent: Wednesday, December 19, 2007 3:31 PM To: Siva Prasad Cc: Clemens Koller; David Newall; linux-kernel@vger.kernel.org Subject: RE: printf internals On Wed, 2007-12-19 at 14:33 -0800, Siva Prasad wrote: > Thank you very much for your response Clemens. > > I tried strace on a regular system. It does not show which tty, etc., as it uses the stdout (fd = 1) and write(1, ...) to it. > > This is not a student project. I am trying to build my own kernel and ramdisk. Kernel boots fine to a point where it starts accessing ramdisk and executes init scripts. From there on nothing gets printed. I did some debugging and found that prints of user land programs are not coming to the serial console, while kernel prints are working fine. I found all the programs getting executed, by placing a printk in execve routine and printing the arguments. > > So, I wanted to trace down the path from user program to the kernel and see why it is not printing messages from user program. I placed a printk in drivers/char/tty_io.c:tty_write() and it is not getting called from my file system. I tried the same thing on my good system (say regular PC) and it works as expected. > > Any clues that can help debug this issue is highly appreciated. > How can I get access to the same printf string inside kernel. This sounds like you're printing out the serial console instead. -- Scott <[EMAIL PROTECTED]> AIM: BlueCame1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
