1

I'm trying to use wake-from-halt on my Raspberry Pi A+, but it does not work. According to elinux.org/RPI_safe_mode#cite_note-1 When using bootcode.bin dated 12/04/2012 or later, the same two pins (5 & 6) can be momentarily shorted to wake the Raspberry Pi from the halted state. But this does not work :(

I also tried updating the bootloader. Is this feature implemented for the A+?

uname -a: Linux raspberrypi 4.14.34+ #1110 Mon Apr 16 14:51:42 BST 2018 armv6l GNU/Linux

The script to halt the raspberry pi is working without any problems

  • Wake from halt? You mean booting from Etherrnet? – not2qubit May 9 '18 at 20:14
  • According to elinux.org/RPI_safe_mode#cite_note-1 When using bootcode.bin dated 12/04/2012 or later, the same two pins (5 & 6) can be momentarily shorted to wake the Raspberry Pi from the halted state. But this does not work :( – TOAOGG May 9 '18 at 20:22
  • Maybe the A+ has RUN pins (or holes...) marked on the board you could use instead? Those should not require any firmware revision. – goldilocks May 9 '18 at 20:38
  • 1
    Aha, did you try this? – not2qubit May 9 '18 at 20:41
  • 1
    P6 -> that's what I was thinking about with the "RUN pins". – goldilocks May 9 '18 at 21:02
1

I an not sure you can actually "halt" the Pi with current Raspbian (although you may be able to write assembler to do so); all the normal shutdown commands run the same code.

The pin 5/6 does work (subject to a few caveats) - although I haven't tried on an A+ it works on all the B models.

If you want safe shutdown, Raspbian now includes code to do this dtoverlay=gpio-shutdown you don't need ANY code. See Raspberry Pi 3 model B "dtoverlay=gpio-shutdown"

  • I explore the halt vs power off call stack through the kernel in an answer of mine. It appears a shutdown through the reboot syscall with LINUX_REBOOT_CMD_POWER_OFF or LINUX_REBOOT_CMD_HALT , which is the case for shutdown -h triggers the system to prime for reset, this is the intended use case of the run pin IIRC – crasic Mar 4 at 7:32

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.