[Python-Dev] CPython on Windows ARM32

[Steve Dower]

Just confirming for the list that I'm aware of this and supportive, but
am not the dedicated support for this effort.

I also haven't reviewed the changes yet, but provided nobody is strongly
opposed to taking on a supported platform (without additional releases
on python.org), I expect I'll do a big part of the reviewing then.

Cheers,
Steve

On 05Feb.2019 1709, Paul Monson via Python-Dev wrote:
> Hi Python Developers,
> 
> I'm Paul Monson, I've spent about 20 years working with embedded
> software.  Since 2010 I've worked for Microsoft as a developer.
> 
> Our team is working with CPython on Azure IoT Edge devices that run on
> x64-based devices.
> 
> We would like to extend that support to Windows running on ARM 32-bit
> devices and have a working proof-of-concept.  Our team is prepared to
> provide support for CPython for Windows on ARM32 for 10 years, and to
> provide build bots for ARM32.
> 
> I like to propose that the initial sequence of PRs could be:
> - Update to OpenSSL 1.1.1 (without anything ARM specific) - ready to go
> - Migrate to libffi directly (finish https://github.com/python/cpython/pull/3806)
> - Build file updates for OpenSSL ARM and check into cpython-bin-deps
> - Build file updates for CPython ARM
> - ctypes updates for ARM
> - Test module skips for ARM
> - Library updates and related test fixes for ARM
> 
> Updating OpenSSL and libffi are independent of ARM support but need to
> be done as prerequisites.  OpenSSL 1.1.0 doesn't have support for ARM32
> on Windows but OpenSSL 1.1.1 does.
> 
> I have OpenSSL 1.1.1a ready to check in to master with all tests passing
> on x86 and x64 on Windows.  Since work has already been done on this for
> other platforms only very small changes were needed for Windows.
> 
> I have also integrated and tested the current libffi on Windows x64. 
> Some additonal porting of x86 assembler to MSVC tools will need to be
> done.  I have a working port of ARM32 assembler for MSVC but it may need
> to be brought up to date and cleaned up.
> 
> The last four all need to go in together, but can be reviewed separately.
> 
> We are not planning to support Tk/Tcl on ARM32 because Windows IoT Core,
> Windows containers don't support GDI, which is a depenency of Tk/Tcl.
> 
> Since Window IoT Core and Windows container don't support the .msi or
> .exe installers found on python.org my team at Microsoft will build the
> CPython for Windows ARM32 from the official repo and distribute it.
> 
> Thanks in advance,
> 
> Paul