Hi Simon,
I agree with Will’s response, the problem you have with
“inherit’ing” BSPs, at least at this stage, is that the APIs are
changing, and everything that inherits the BSP will have to change as we
morph APIs.
However, you shouldn’t have to maintain a different BSP for every
slightly different version of your own boards. If you use something
called features, you can control these settings.
A good example of this is the Arduino zero BSP, here:
https://github.com/runtimeinc/mynewt_arduino_zero
If you look at the pkg.yml in hw/bsp/arduino_zero
(https://github.com/runtimeinc/mynewt_arduino_zero/tree/master/hw/bsp/arduino_zero),
you’ll see the following lines:
pkg.cflags.arduino_zero_pro: -DARDUINO_ZERO_PRO
pkg.cflags.arduino_zero: -DARDUINO_ZERO
This changes the values of the CFLAGS based upon which feature is set,
either arduino_zero or arduino_zero_pro. This is to accommodate the
fact that on the board, two pins are swapped depending on whether you
get it from .cc or .org. The C code can then check this with #ifdefs.
Features allow you to change dependencies, cflags, lflags and anything
else, depending on which features are set in the build system. Features
can be either specified as a package variable (pkg.features), or at the
target level by doing
$ newt target set your_target features=“feature1 feature2”
Features are global to the build system, and everything will respect
them.
sterling
On 8 Jun 2016, at 12:43, Simon Ratner wrote:
I would like to create a couple of custom bsps for boards which are
identical to nrf51dk but a few small tweaks (e.g. led pin, flash area
layout).
From the docs, I gather that copying hw/bsp/nrf51dk and patching bsp.h
and
os_bsp.c would do the trick, and it seems that's how mynewt itself
handles
this. However, I'd really prefer not to, so I can keep up with
upstream and
avoid duplicating fixes in multiple places (like
https://github.com/apache/incubator-mynewt-core/commit/c70353c193bf3e91a095cfc5076ac578f8e1bc69).
Any suggestions on how to best layer my tweaks on top of an existing
bsp?
Can I abuse the deps system somehow?
Simon.
