mp_kbd_exception is now considered the standard variable name to hold the
singleton KeyboardInterrupt exception.
This patch also moves the creation of this object from pyb_usb_init() to
main().
Previous to this patch pyboard.py would open a new serial connection to
the target for each script that was run, and for any command that was run.
Apart from being inefficient, this meant that the board was soft-reset
between scripts/commands, which precludes scripts from accessing variables
set in a previous one.
This patch changes the behaviour of pyboard.py so that the connection to
the target is created only once, and it's not reset between scripts or any
command that is sent with the -c option.
When printing exceptions from files sent to a target by pyboard.py the
filename in the exception is <stdin>, which differs to when running the
script on the PC. So we strip out the filename to make the outputs the
same on all targets (see also misc/print_exception.py test).
sys.exit() is an important function to terminate a program. In particular,
the testsuite relies on it to skip tests (i.e. any other functionality may
be disabled, but sys.exit() is required to at least report that properly).
For all but the last pass the assembler only needs to count how much space
is needed for the machine code, it doesn't actually need to emit anything.
The dummy_data just uses unnecessary RAM and without it the code is not
any more complex (and code size does not increase for Thumb and Xtensa
archs).
Damien George
Lorenz Schmid
Paul Sokolovsky
Rami Ali