Well, Dummy me tried this on a good one. Now have two that are bricked. Software revised and broke?
This is the output:
Open On-Chip Debugger 0.11.0-rc1+dev-00001-g0dd3b7fa6-dirty (2020-12-21-17:00)
Licensed under GNU GPL v2
For bug reports, read
http://openocd.org/doc/doxygen/bugs.html
Info : BCM2835 GPIO JTAG/SWD bitbang driver
Info : clock speed 400 kHz
Info : SWD DPIDR 0x0bc11477
Info : at91samd21g18.cpu: hardware has 4 breakpoints, 2 watchpoints
Info : starting gdb server for at91samd21g18.cpu on 3333
Info : Listening on port 3333 for gdb connections
target halted due to debug-request, current mode: Thread
xPSR: 0xf0000000 pc: 0x213c0a0a msp: 0x0a0a0a08
Info : SAMD MCU: SAMD21G18A (256KB Flash, 32KB RAM)
Error: at91samd21g18.cpu – clearing lockup after double fault
target halted due to debug-request, current mode: Handler HardFault
xPSR: 0xf1000003 pc: 0xfffffffe msp: 0x0a0a09e8
shutdown command invoked
They both lock up after double fault. If I request debug, it goes on and on.