On 12/19/07, Siva Prasad <[EMAIL PROTECTED]> wrote: > > 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"
Adding a CONSOLE=/dev/ttyS0 works for me on both Debian and Redhat; You also want a inittab entry for console on serial device. (use google and find it yourself). cheers, Masoud > 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/ > -- 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/
