mip: Support replacing MPY_VERSION and MPY_ARCH variables

Allows to use a single URL to specify a native module package,
and mip will then lookup the correct hardware architecture
and MicroPython ABI version.

Author: jonnor

micropython/mip/mip/__init__.py

@@ -24,6 +24,25 @@
 
 _ALLOWED_MIP_URL_PREFIXES = const(("http://", "https://", "codeberg:", "github:", "gitlab:"))
 
+# NB: Must be in the correct order wrt sys.implementation._mpy
+MPY_ARCHITECTURES = [
+        None,
+        'x86', 'x64',
+        'armv6', 'armv6m', 'armv7m', 'armv7em', 'armv7emsp', 'armv7emdp',
+        'xtensa', 'xtensawin', 'rv32imc', 'rv64imc'
+]
+
+def _get_mpy_arch_version():
+
+    sys_mpy = sys.implementation._mpy
+    sys_arch = (sys_mpy >> 10) & 0x0F
+
+    mpy_major = sys_mpy & 0xff
+    mpy_minor = sys_mpy >> 8 & 3
+    mpy_arch =  MPY_ARCHITECTURES[sys_arch]
+
+    return mpy_arch, mpy_major, mpy_minor
+
 
 # This implements os.makedirs(os.dirname(path))
 def _ensure_path_exists(path):
@@ -74,6 +93,12 @@ def _check_exists(path, short_hash):
 
 
 def _rewrite_url(url, branch=None):
+    # substitute markers for native modules (if present)
+    mpy_arch, mpy_major, mpy_minor = _get_mpy_arch_version()
+    mpy_version = f'{mpy_major}.{mpy_minor}'
+    url = url.replace('{MPY_VERSION}', mpy_version)
+    url = url.replace('{MPY_ARCH}', mpy_arch)
+
     for provider, url_format in _HOSTS.items():
         if not url.startswith(provider):
             continue