Building ZT1 on Windows arm64 arch

[bradsoto]

When building zerotier-one for Windows on arm64 I encounter the following error:

This header is specific to X86 and X64 targets

Inside the file node/Salsa20.hpp:

#if (!defined(ZT_SALSA20_SSE)) && (defined(__SSE2__) || defined(__WINDOWS__))
#define ZT_SALSA20_SSE 1
#endif

This is not true for Windows on arm64. The compilation pulls in emmintrin.h (where the first error originates). When I remove that header I get errors about sse2-specific instructions, and it fails as well. It seems like the change has to happen both in Salsa20.hpp and in the solution file.

[bradsoto]

I was able to get the driver to build for arm64 using WDK 16299 by adding a configuration "Win10 Release" and a platform arm64 to the solution files and defining

#define _ARM64_ 1
#define NDIS670

However I am left with .obj files and no linked driver. Looks like OpenVPN has has the tap driver available since April 2019.

OpenVPN/tap-windows6#75