Hi all, I have not been able to fix the issue with early printk. I still believe that it is not supported in the 2.6.32 open source kernel for davinci. However, I was able to fix problem with the kernel (by trial and error) and kernel boot is ok now.
Thanks every one for your help on this issue. Regards, Kunal On Sun, Oct 3, 2010 at 10:46 AM, kunal singh <[email protected]> wrote: > While doing the early console set up, there is a function call to > drivers/serial/8250_early.c/serial8250_find_port_For_earlycon() > > The above function always returns with an error condition. It does checks > on the early_device and these checks fail (it fails because the > early_device.port is un-initialized). > > I checked the code and see that early_device (which is a static variable) > is never intialzed any where in the code drivers/serial/8250_early.c. I > wonder if the earlycon support has been added for 2.6.32 kernel? any > suggestions? > > > On Thu, Sep 30, 2010 at 9:18 PM, kunal singh <[email protected]>wrote: > >> Tried with earlyprintk, but the problem persists >> >> >> On Thu, Sep 30, 2010 at 8:45 PM, kunal singh <[email protected]>wrote: >> >>> Hi Hemant, >>> >>> No I have not added the earlyprintk. I will investigate this. Shall I >>> add earlyprintk=serial,uart0 ? >>> >>> BTW, I tried to trace down the printk code flow in kernel/printk.c. >>> (1) in the function _call_console_drivers(), __call_console_drivers() >>> never gets called [the if() condition is never met]. >>> (2) May be it probably explains why nothing gets printed on serial? Is >>> this because there is no earlyprintk in bootargs? >>> >>> Regards, >>> kunal >>> >>> >>> >>> >>> >>> On Thu, Sep 30, 2010 at 8:19 PM, Pedanekar, Hemant <[email protected]>wrote: >>> >>>> Just to check: have you added "earlyprintk" to your bootargs? >>>> >>>> - >>>> Hemant >>>> >>>> >>>> >>>> ------------------------------ >>>> *From:* kunal singh [mailto:[email protected]] >>>> *Sent:* Thursday, September 30, 2010 7:40 PM >>>> *To:* Raffaele Recalcati; Nori, Sekhar; Pedanekar, Hemant >>>> >>>> *Cc:* [email protected] >>>> *Subject:* Re: problem with serial console >>>> >>>> Hi All, >>>> >>>> >>>> Thanks a lot for posting the comments here. >>>> >>>> (1) I have added some printascii() statements in function >>>> init/main.c/start_kernel() to trace the boot sequence >>>> (a) printascii() to print the command line arguments >>>> (b) printascii() before doing the console_init() >>>> (c) printascii() after doing the console_init() >>>> >>>> (2) The log (posted below) suggests that the boot sequence goes beyond >>>> console_init(). Since console_init is done I would expect that all my >>>> printk >>>> messages should start to appear on the console . But it does not. (however >>>> the printascii still works, as you can see messages in the bootlog, hence I >>>> would assume that hardware is fine) >>>> >>>> I would appreciate if you can give some suggestion on how to debug >>>> this issue further. >>>> >>>> Thanks, >>>> kunal >>>> >>>> >>>> /************* HERE IS THE BOOT LOG ****************************/ >>>> run devboot >>>> TFTP from server 10.0.0.1; our IP address is 10.0.0.3 >>>> Filename '/home/kunal/xcaster/ingenient-bsp/images/uImage'. >>>> Load address: 0x82000000 >>>> Loading: #T >>>> ################################################################ >>>> >>>> ################################################################# >>>> #################T >>>> ################################################ >>>> >>>> ################################################################## >>>> ###################T ##########T >>>> #################################### >>>> ##########################################T #### >>>> done >>>> Bytes transferred = 1898780 (1cf91c hex) >>>> ## Booting image at 82000000 ... >>>> Image Name: Linux-2.6.32-rc2-davinci1 >>>> Image Type: ARM Linux Kernel Image (uncompressed) >>>> Data Size: 1898716 Bytes = 1.8 MB >>>> Load Address: 80008000 >>>> Entry Point: 80008000 >>>> Verifying Checksum ... OK >>>> OK >>>> >>>> Starting kernel ... >>>> >>>> Uncompressing >>>> Linux........................................................................................................................... >>>> done, booting the kernel. >>>> >>>> console=ttyS0,115200n8 root=/dev/nfs rw >>>> nfsroot=10.0.0.1:/home/kunal/xcaster/ingenient-bsp/rootfs/fs,udp,v3,rsize=4096,wsize=1400 >>>> ip=10.0.0.3:10.0.0.1:10.0.0.1:255.255.255.0:XCASTER5000::off mem=128M >>>> mtdparts=davinci-nand.0:96k(ubl),736k(uboot),64k(uboot-env),2m(kernel),61568k(app) >>>> eth=80:4C:EF:54:87:0A >>>> doing console init now >>>> finished console init >>>> >>>> /***************************************************************/ >>>> >>>> >>>> On Thu, Sep 30, 2010 at 6:26 PM, Raffaele Recalcati < >>>> [email protected]> wrote: >>>> >>>>> On Thu, Sep 30, 2010 at 2:35 PM, kunal singh <[email protected]> >>>>> wrote: >>>>> > Hi Raffaele, >>>>> > >>>>> > Thanks for the suggestion. >>>>> > >>>>> > (1) Console is fine. I am able to communicate with the u-boot >>>>> (115200,n8). >>>>> > Also if I use printascii (a kernel function) I am able to output on >>>>> console. >>>>> > (2) There is no message, after the kernel decompression (because >>>>> console is >>>>> > not up). Here is what I see. >>>>> > >>>>> > Load address: 0x82000000 >>>>> > Loading: ####T ###################T >>>>> > ########################################## >>>>> > >>>>> ################################################################## >>>>> > ######################T >>>>> > ############################################ >>>>> > >>>>> ################################################################# >>>>> > ###################T >>>>> > ##############################################T ## >>>>> > ######T ######################################## >>>>> > done >>>>> > Bytes transferred = 1898828 (1cf94c hex) >>>>> > ## Booting image at 82000000 ... >>>>> > Image Name: Linux-2.6.32-rc2-davinci1 >>>>> > Image Type: ARM Linux Kernel Image (uncompressed) >>>>> > Data Size: 1898764 Bytes = 1.8 MB >>>>> > Load Address: 80008000 >>>>> > Entry Point: 80008000 >>>>> > Verifying Checksum ... OK >>>>> > OK >>>>> > >>>>> > Starting kernel ... >>>>> > >>>>> > Uncompressing >>>>> > >>>>> Linux........................................................................................................................... >>>>> > done, booting the kernel. >>>>> > >>>>> > /* AND THEN NOTHING BECAUSE CONSOLE IS NOT FUNCTIONAL, but booting >>>>> goes on >>>>> > */ >>>>> >>>>> How can you say that boot goes on? >>>>> Can you check mem inside bootargs? >>>>> For instance I have 128MB RAM and I use these bootargs. >>>>> >>>>> set bootargs 'console=ttyS0,115200n8 rw >>>>> ip=10.39.10.183:10.39.10.169:10.39.8.1:255.255.248.0:::off >>>>> root=/dev/nfs nfsroot=10.39.10.169:/home/NFS/ARAGO_DEMO_IMAGE-raf/ >>>>> mem=128M video=davincifb:output=lcd:format=rgb:vid0=240x...@0 >>>>> ,0:vid1=240x...@0,0:osd0=240x...@0,0:osd1=240x...@0,0 >>>>> ' >>>>> >>>>> Don't copy my bootargs, only do some tests. >>>>> I saw your behaviour when mem was wrong. >>>>> >>>> >>>> >>> >> >
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