Find the answer to your Linux question:
Results 1 to 5 of 5
Hi, Is there any way to get boot logs when kernel is broken and can't boot? I have two kernels, one is good and second is modified by me. I ...
Enjoy an ad free experience by logging in. Not a member yet? Register.
  1. #1
    Just Joined!
    Join Date
    Aug 2012
    Posts
    3

    Kernel boot process debugging when system can't start up


    Hi,
    Is there any way to get boot logs when kernel is broken and can't boot?

    I have two kernels, one is good and second is modified by me. I must see where are errors in the second one.

  2. #2
    Just Joined!
    Join Date
    Sep 2012
    Posts
    1

    Try using menu config

    From the kernel hacking which is located at the menu config, you can turn on debugging phases such as the boot sequence,
    What kernel are you using and which architecture ?

  3. #3
    Linux Enthusiast
    Join Date
    Jan 2005
    Location
    Saint Paul, MN
    Posts
    649
    Quote Originally Posted by cnyk View Post
    Hi,
    Is there any way to get boot logs when kernel is broken and can't boot?

    I have two kernels, one is good and second is modified by me. I must see where are errors in the second one.
    • Boot the working kernel
    • Does "/proc/config.gz" exist? If so, then you have the current kernel configuration file and can proceed.
    • cd /usr/src/linux
    • zcat /proc/config.gz > .config_working
    • At this point a use a difference program to compare kernel options (such as but not limited to gvimdiff, vimdiff, tkdiff, diff, sdiff) but it needs to be text based. I like the use "gvimdiff" or "vimdiff" and finally "tkdiff" because the "gvimdiff" and "tkdiff" are GUI based and "gvimdiff" and "vimdiff" are editors while doing the diff.
    • While doing the diff look for filesystem support, device support, initramfs support, etc. When doing the diff, you will not have any help text as when in "make menuconfig" (or "make gconfig" or "make xconfig" which are GUI versions for Gnome and KDE).

    More help might be available if you posted a screen shot of the boot upto the kernel panic.

  4. #4
    Just Joined!
    Join Date
    Aug 2012
    Posts
    3
    I have config and source code of working kernel but it's 2.6.29 version and I'm porting 3.5.2.
    It's ARM MSM7227 device.

  5. #5
    Linux Enthusiast
    Join Date
    Jan 2005
    Location
    Saint Paul, MN
    Posts
    649
    Sorry, I have not anything with arm since the 2.4.x versions.

    You could start by putting the current 2.6.9 config file into the the 3.5.2 tree and running:
    Code:
    make bzxImage
    It will prompt for values for any missing config information. Also there has been driver replacements made between 2.x and 3.x kernel versions.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •