WATCHDOG BREAKDOWN

Two watchdogs :

• IMX internal ARM chip watchdog:
• (APX external apx chip watchdog, this repo concerns IMX Watchdog only

IMX WATCHDOG

http://www.nxp.com/assets/documents/data/en/reference-manuals/IMX6SLRM.pdf

Devregs (tool for reading and setting registers) :

• https://github.com/boundarydevices/devregs
• copy .dat files to /etc/
• compile src/devregs.cpp with :
  • arm-linux-gnueabihf-g++ -static -march=armv7 devregs.cpp -o devregs

0x20bc000 watchdog :

• write 0x0034 activate with 0.5 sec timout
• write 0xff34 activate with 128sec timeout
• example : devregs 0x20BC000 0xFF34

0x20bc002 ping address:

• write 0x5555 and subsequently 0xAAAA for reset timer (this is what the wd_keepalive service is for)
• example :
  • devregs 0x20BC002 0x5555
  • devregs 0x20BC002 0xAAAA

syntax for devregs is :

• read : devregs 0x20bc000
• write : devregs 0x20bc000 0x0034

this repo installs :

• 'imx-watchdog' service at a 10second interval which starts up as the first service. For enabling watchdog sooner (at bootloader ) check this repository : https://github.com/gerdmestdagh/u-boot-watchdog-enabled
• 'imx-keepalive' service which pings the watchdog every 5 seconds
• Install with:
  • sudo apt-get update
  • wget -q -O - http://bit.ly/2k9RKzu | bash