[Ubuntu Wiki] Update of "DebuggingKernelBoot" by brian-murray

[Ubuntu Wiki]

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The following page has been changed by brian-murray:
http://wiki.ubuntu.com/DebuggingKernelBoot?action=diff&rev1=9&rev2=10

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   1. Boot the machine.
   1. During the BIOS screen, press the shift key and hold it down. You should get the GRUB menu after the BIOS loads.
   1. Navigate to the kernel entry you want to boot, and press 'e'.
-  1. Then remove the '''quiet''' and '''splash''' keywords and press 'Ctrl+x' to boot.
+  1. Then remove the '''quiet''' and '''splash''' keywords (found in the line starting with linux) and press 'Ctrl+x' to boot.
  
  It's best if you can attach a log file which may have captured any messages you see.  If you are unable to capture a log file, a digital photo will work just as well.  As a last resort you can even copy messages down by hand.
  
  Depending on the type of error messages you encounter, there are other boot options you could try.  For example, if you notice ACPI errors, try booting with the '''acpi=off''' boot option.  For a full description of these options, refer to the [[http://www.kernel.org/doc/Documentation/kernel-parameters.txt|kernel parameters]] document.
  
  == Initramfs ==
- Sometimes you may even be dropped into an initramfs shell.  Obviously this indicates errors in the boot sequence, for example failing to find your root partition/filesystem.  You are dropped into the initramfs shell in an effort to allow you to recover the system.  Hopefully if you boot with the '''quiet''' and '''splash''' options removed you will notice error messages before being dropped into the shell which will help debug and direct you to a solution.
+ Sometimes you may even be dropped into an initramfs shell.  This indicates errors in the boot sequence, for example failing to find your root partition/filesystem.  You are put into the initramfs shell in an effort to allow you to recover the system.  Hopefully, if you boot with the '''quiet''' and '''splash''' options removed you will notice error messages before being dropped into the shell which will help debug and direct you to a solution.
  
  If you are dropped into an initramfs shell you may want to also try booting with the '''debug''' boot option.  It should write a log to /tmp/initramfs.debug.  You could also specify some arbitrary argument (for example '''debug=vc''') to have the output written to the console.