Hi, I am trying to port 3.18 kernel to a S3C2416. Years ago, a guy helped me ported a 3.1.0 kernel to the same board, and the guy left and the kernel got too old. The guy also ported an u-boot as boot loader to load the 3.1.0 kernel. I had the source code of the ported u-boot and the 3.1.0 linux. Now, my problem is that my porting of 3.18 seems not working, I did not see any kernel message printed to the first SoC serial port as I expected. As long as I can get kernel message printed to the serial, I think I can step by step finish the whole porting work eventually. But now, there is no message and I have no other hardware debugging tools and knowledges, I felt I lost my way totally. I hope someone can give me some suggestions, clues to help me understand where to check and what's the possible causes. Since I found the old porting of the 3.1.0 is quit similar to SMDK2416, then I started my work from also the SMDK2416 board code in 3.18. Basically, I defined the machine-code to match that passed from u-boot, and copied the MACHINE-START definition section with removing of some not-immediately-needed stuff such as USB, NAND and HMSUI etc. I also enabled the S3C2410 serial driver and enabled the serial console supporting for the Samsung SoC. Of course, I had the kernel parameter of "console=ttySAC0", ttySAC0 is the Linux device name of the first UART port in the SoC. These are basically what I had done and I guess the SoC serial part between my board and SMDK2416 should be very similar and the kernel should at least be able to print it's first message then I should have chance to fix other differences. But there is no kernel message at all as I mentioned above. What should I check for the problem usually? Is there a checking list to go through? I hope you experts can give me some clues. Thanks in advance! Best Regards, woody -- Life is the only flaw in an otherwise perfect nonexistence -- Schopenhauer woody public key at http://subkeys.pgp.net:11371 (narkewoody@gmail.com)