The -EIO error was triggering a warning in the caller.

Make private functions static
Allocate buffers on stack
Move constants out of header

Pycardium Improvements

Closes #76 and #212

See merge request card10/firmware!417

This will result in more reliably reaching a clean state.

Co-Authored-By: schneider <schneider@muc.ccc.de>
Signed-off-by: Rahix <rahix@rahix.de>

See merge request !418

Also auto generate the header during build time.

Instead of "rebooting" Pycardium, hand over control to core 0, notifying
it of a severe failure via epic_exit(253).

Signed-off-by: Rahix <rahix@rahix.de>

Calls to abort() shouldn't make core 1 busy-spin; call epic_exit()
instead.  Fixes #76.

Signed-off-by: Rahix <rahix@rahix.de>

Instead of dropping to REPL and silently requiring the user to return to
menu via button-press, directly call epic_exit(0) when a script
terminates execution normally (i.e. not via exception).

Signed-off-by: Rahix <rahix@rahix.de>

Remove the big endless loop from pycardium main and instead use
epic_exec("") to switch to REPL.  This way, any MicroPython state is
reset and also all hardware will be in a clean reinitialized state.

This also means that pycard10.py will now run scripts in a clean
environment that is not tainted by whatever was running before.

Fixes #212.

Signed-off-by: Rahix <rahix@rahix.de>