Difference between revisions of "RPI safe mode"
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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. | 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. | ||
+ | [[File:Jump-pins-5-6.jpg|left|thumb|500px|20 AWG wire used to connect P1 pins 5 and 6 to boot RPi into safe mode. Also, 20 AWG wire insulation used to protect the power pins on the P1 header from accidentally being shorted to another pin or each other. ]] | ||
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More info: | 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 11:22, 28 December 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