Difference between revisions of "RPI safe mode"

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(Created page with "No text yet, see this post for information on safe mode. http://www.raspberrypi.org/phpBB3/viewtopic.php?f=29&t=12007")
 
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No text yet, see this post for information on safe mode.
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This results in config.txt being ignored (except for avoid_safe_mode). A default cmdline.txt is applied, and kernel_emergency.img is loaded (if not available, then just kernel.img).
  
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It provides a means of recovering from, e.g.
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* too high an overclock
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* a typo in cmdline.txt
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* an incorrect kernel=<filename> parameter
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* an invalid display mode
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without requiring a PC.
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(Obviously it won't help if you've deleted start.elf...)
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The busybox based kernel_emergency.img has /boot mounted, and vi installed so you can fix up config.txt or cmdline.txt.
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(You can also mount /dev/mmcblk0p2 and fix up the rootfs if you have problems there that stop you booting).
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Short Jumpers 5&6.
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Be very careful with where you insert the jumper. Some pins carry power, so shorting those would not be a good idea. Third row from the end.
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More info:
 
http://www.raspberrypi.org/phpBB3/viewtopic.php?f=29&t=12007
 
http://www.raspberrypi.org/phpBB3/viewtopic.php?f=29&t=12007

Revision as of 19:44, 30 August 2012

This results in config.txt being ignored (except for avoid_safe_mode). A default cmdline.txt is applied, and kernel_emergency.img is loaded (if not available, then just kernel.img).

It provides a means of recovering from, e.g.

  • too high an overclock
  • a typo in cmdline.txt
  • an incorrect kernel=<filename> parameter
  • an invalid display mode

without requiring a PC. (Obviously it won't help if you've deleted start.elf...)

The busybox based kernel_emergency.img has /boot mounted, and vi installed so you can fix up config.txt or cmdline.txt. (You can also mount /dev/mmcblk0p2 and fix up the rootfs if you have problems there that stop you booting).

Short Jumpers 5&6. Be very careful with where you insert the jumper. Some pins carry power, so shorting those would not be a good idea. Third row from the end.


More info: http://www.raspberrypi.org/phpBB3/viewtopic.php?f=29&t=12007