On Wednesday, February 24, 2016, nick <xerofo...@gmail.com> wrote: > > > On 2016-02-23 09:35 AM, Woody Wu wrote: > > 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. > > > Firstly my knowledge with kernel upstream porting to a non mainlined > port is not as good as some of the other people here but let's see what > I can do.
> 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. > > Can you either send me the patch series that the other developer used to > port > your port to 3.1.0 or I would recommend stating on kernel 3.1.0 as it's > still > a longterm kernel unless you have reason to upgrade. If you do I would > recommend > you either get something with experience or yourself to try and upstream > the > differences between your board and the mainline so others will not have to > do > the same work as you unless your company will not allow you to do this. > > 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! > > To make a patch, I have to have the original 3.1.0, but I was confused about how the kernel.org organized, I just cannot find how to get a 3.1.0 tarball or git repository. Can you please give me a hint? BTW, I also dont really understand what the 'mainline' mens. If I download a latest 3.18.27.tar.xz, is it a mainline? > Their are two things you can do here either try and enable early_printk as > this > seems to be happening before the serial console is able to print the first > kernel > message. The second is trying to enable kgdb on the board and use another > computer > over the serial port to do this sort of debugging. > Hope this gets you started, > Nick Firstly, I will try early_printk soon. Before that, can your tell me what are differences betweenthe following printing technologies: 1, early_printk 2, early_print, 3, putc used in arch/arm/compressed/misc.c. Secondly, I have a question about kgdb. You see the situation is that my serial port had been initialized by the u-boot, but not yet touched by the kernel since the kernel is not yet run and waiting for debugging, and now I am jusr sitting in the u-boot command prompt and has an uImage kernel image file loaded in a region of SDRAM, do you think that these all above are enough or possible to the kgdb debugging? Many thanks! > Best Regards, > > woody > > > > > > > > > > _______________________________________________ > > Kernelnewbies mailing list > > Kernelnewbies@kernelnewbies.org <javascript:;> > > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > > > -- Life is the only flaw in an otherwise perfect nonexistence -- Schopenhauer woody public key at http://subkeys.pgp.net:11371 (narkewo...@gmail.com)
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