Difference between revisions of "RPI safe mode"

From eLinux.org
Jump to: navigation, search
(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")
 
Line 1: Line 1:
No text yet, see this post for information on safe mode.
+
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
 
http://www.raspberrypi.org/phpBB3/viewtopic.php?f=29&t=12007

Revision as of 12:44, 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