Kernel Debug

Hi Ali,

Have you tried to use "dmesg" command ?

Try to use simple "printk" in kernel driver or board file.

printk("PRINT TEST\n");

Hi Titus,

I have tried simple printk and that has not worked.

I have not done the dmesg command can you guide me how to perform that.

Regards

Ali

Hi Ali,

"dmesg" command is linux command which is used to print the messages from kernel.

Ex:

bash-3.2#

bash-3.2#

bash-3.2# dmesg
[    0.000000] Linux version 3.2.0 (titus@Titus) (gcc version 4.7.3 20130226 (prerelease) (crosstool-NG linaro-1.13.1-4.7-2013.03-201
30313 - Linaro GCC 2013.03) ) #186 Mon Aug 18 19:44:18 IST 2014
[    0.000000] CPU: ARMv7 Processor [413fc082] revision 2 (ARMv7), cr=10c53c7d
[    0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache

Hi Titus,

I have tried that to no avail. I have also tried the simple printk command as you mentioned but nothing seems to be printing. From the same board specific file I get other messages like

printk(KERN_DEBUG "VAR_SOM_OM3X_enable_lcd\n");

The above message gets printed but is defined in the subroutine which gets registered using API

platform_add_devices(VAR_SOM_OM3X_devices, ARRAY_SIZE(VAR_SOM_OM3X_devices));

What I have got defined is below lines at the start of my init routine

static void __init VAR_SOM_OM3X_init(void)
{
    printk("Board Init\n");
    printk(KERN_EMERG "Board Init KERN_EMERG\n");
    printk(KERN_ALERT "Board Init KERN_ALERT\n");
    printk(KERN_CRIT "Board Init KERN_CRIT\n");
    printk(KERN_ERR "Board Init KERN_ERR\n");
    printk(KERN_WARNING "Board Init KERN_WARNING\n");
    printk(KERN_NOTICE "Board Init KERN_NOTICE\n");
    printk(KERN_INFO "Board Init KERN_INFO\n");
    printk(KERN_DEBUG "Board Init KERN_DEBUG\n");

    omap3_mux_init(board_mux, OMAP_PACKAGE_CUS);

None of these get printed.

Regards

Ali

Hi Ali,

Could you please share your complete bootup log (if you got something in console) and bootcmd & bootargs.

Are you getting any console print messages after "uncompressing kernel" ?

Just check your bootargs whether you are using any "silent" arg.

Hi Titus,

Thanks for your reply. I have been away from office for few days hence was not able to reply quick. I think I have figured out the problem. I renamed some files and did not change my makefile and KConfig files which I have now changed. The problem was the old files were being pulled due to makefile being incorrect. Since I have changed my makefile it seems ok but the problem I now have is when I do a clean and then make of kernel I am getting error which is

arm-eabi-ld: no machine record defined

The only thing I have changed is the Kbuild file and defconfig file to include support for the custom board. The macro I have defined in _defconfig file is

CONFIG_MACH_HAWKIII=y

in place of the previous one. I have never seen this error before and kind of lost. Any help on this would be great.

Thanks

Ali

Hi Ali,

Use "make mrproper" command then try to build kernel.

Hi Titus,

I have just tried to do below but to no avail

make ARCH=arm CROSS_COMPILE=arm-eabi- mr proper

make ARCH=arm CROSS_COMPILE=arm-eabi- hawkIII_defconfig

make ARCH=arm CROSS_COMPILE=arm-eabi- uImage

Regards

Ali

Sorry Typo error to above

Hi Titus,

I have just tried to do below but to no avail

make ARCH=arm CROSS_COMPILE=arm-eabi- mrproper

make ARCH=arm CROSS_COMPILE=arm-eabi- hawkIII_defconfig

make ARCH=arm CROSS_COMPILE=arm-eabi- uImage

Regards

Ali

Hi Titus,

On building the kernel the last few lines are before the error

  CC      lib/reciprocal_div.o
  CC      lib/rwsem-spinlock.o
  CC      lib/sha1.o
  CC      lib/show_mem.o
  CC      lib/string.o
  CC      lib/vsprintf.o
  AR      lib/lib.a
  LD      vmlinux.o
  MODPOST vmlinux.o
WARNING: modpost: Found 3 section mismatch(es).
To see full details build your kernel with:
'make CONFIG_DEBUG_SECTION_MISMATCH=y'
  GEN     .version
  CHK     include/generated/compile.h
  UPD     include/generated/compile.h
  CC      init/version.o
  LD      init/built-in.o
  LD      .tmp_vmlinux1
arm-eabi-ld: no machine record defined
arm-eabi-ld: no machine record defined
make: *** [.tmp_vmlinux1] Error 1

Regards

Ali

Hi Ali,

The issue seems to be the toolchain issue.

Have you got success before with this toolchain (arm-eabi-) for the same linux source ?

Why don't you arago toolchain or provided by TI with SDK ?

make ARCH=arm CROSS_COMPILE=arm-arago-linux-gnueabi- clean

make ARCH=arm CROSS_COMPILE=arm-arago-linux-gnueabi- distclean

make ARCH=arm CROSS_COMPILE=arm-arago-linux-gnueabi- mrproper

make ARCH=arm CROSS_COMPILE=arm-arago-linux-gnueabi- hawkIII_defconfig

make ARCH=arm CROSS_COMPILE=arm-arago-linux-gnueabi- uImage

Hi Titus,

yes it was working yesterday until I changed file names so I am not sure what went wrong in changing the file names. Its been working fine for the last 4 months.

Regards

Ali

Hi have just tried this and again same issue

make ARCH=arm CROSS_COMPILE=arm-eabi- clean

make ARCH=arm CROSS_COMPILE=arm-eabi- distclean

make ARCH=arm CROSS_COMPILE=arm-eabi- mrproper

make ARCH=arm CROSS_COMPILE=arm-eabi- hawkIII_defconfig

make ARCH=arm CROSS_COMPILE=arm-eabi- uImage

Regards

Ali

Hi Ali,

Thanks for your update.

Good luck.