This allows properties defined in programmers.txt to override generic
configurations in platform.txt where needed, for example in the
following configuration:
programmers.txt:
myprog.name=My New Programmer
[...]
myprog.program.tool=avrdude
myprog.config.path={runtime.platform.path}/myprog_avrdude.conf
[...]
platform.txt:
tools.avrdude.path={runtime.tools.avrdude.path}
tools.avrdude.cmd.path={path}/bin/avrdude
tools.avrdude.config.path={path}/etc/avrdude.conf
[...]
tools.avrdude.upload.pattern="{cmd.path}" "-C{config.path}" {upload.verbose} -p{build.mcu} -c{upload.protocol} -P{serial.port} -b{upload.speed} -D "-Uflash:w:{build.path}/{build.project_name}.hex:i"
the generic tools.avrdude.config.path value
{path}/etc/avrdude.conf
is replaced by the more specific myprog.config.path used in "myprog" programmer
{runtime.plaform.path}/myprog_avrdude.conf
Also renamed the touchPort() function, as it's now unambiguously
single-purpose.
The 1200bps reset from Linux hosts wasn't working with these newer
JSSC-based versions. Adding a step which explicitly sets DTR low (via a
TIOCMSET ioctl clearing DTR) fixes this.
I'm fairly sure the reason why this worked on older Arduino with librxtx
and not with jssc is that librxtx appears to keep HUPCL in the termio
flags, but jssc appears to remove it. If HUPCL ("hangup on close") is
set, it causes DTR to be explicitly pulled low on close.
