docs: generate toolchain download links

docs/gen-toolchain-links.py

@@ -0,0 +1,78 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# This script generates toolchain download links and toolchain unpacking
+# code snippets based on information found in $IDF_PATH/tools/toolchain_versions.mk
+#
+
+from __future__ import print_function
+
+import sys
+import os
+
+def main():
+    if len(sys.argv) != 4:
+        print("Usage: gen-toolchain-links.py <versions file> <base download URL> <output directory>")
+        sys.exit(1)
+
+    out_dir = sys.argv[3]
+    if not os.path.exists(out_dir):
+        print("Creating directory %s" % out_dir)
+        os.mkdir(out_dir)
+
+    base_url = sys.argv[2]
+
+    versions_file = sys.argv[1]
+    version_vars = {}
+    with open(versions_file) as f:
+        for line in f:
+            name, var = line.partition("=")[::2]
+            version_vars[name.strip()] = var.strip()
+
+    gcc_version = version_vars["CURRENT_TOOLCHAIN_GCC_VERSION"]
+    toolchain_desc = version_vars["CURRENT_TOOLCHAIN_COMMIT_DESC_SHORT"]
+
+    unpack_code_linux_macos = """
+::
+
+    mkdir -p ~/esp
+    cd ~/esp
+    tar -x{}f ~/Downloads/{}
+"""
+
+    scratch_build_code_linux_macos = """
+::
+
+    cd ~/esp
+    git clone -b xtensa-1.22.x https://github.com/espressif/crosstool-NG.git
+    cd crosstool-NG
+    ./bootstrap && ./configure --enable-local && make install
+"""
+
+    platform_info = [ ["linux64", "tar.gz", "z", unpack_code_linux_macos],
+                      ["linux32", "tar.gz", "z", unpack_code_linux_macos],
+                      ["osx", "tar.gz", "z", unpack_code_linux_macos],
+                      ["win32", "zip", None, None]]
+
+    with open(os.path.join(out_dir, 'download-links.inc'), "w") as links_file:
+        for p in platform_info:
+            platform_name = p[0]
+            extension = p[1]
+            unpack_cmd = p[2]
+            unpack_code = p[3]
+
+            archive_name = 'xtensa-esp32-elf-{}-{}-{}.{}'.format(
+                    platform_name, toolchain_desc, gcc_version, extension)
+            
+            print('.. |download_link_{}| replace:: {}{}'.format(
+                platform_name, base_url, archive_name), file=links_file)
+
+            if unpack_code is not None:
+                with open(os.path.join(out_dir, 'unpack-code-%s.inc' % platform_name), "w") as f:
+                    print(unpack_code.format(unpack_cmd, archive_name), file=f)
+
+    with open(os.path.join(out_dir, 'scratch-build-code.inc'), "w") as code_file:
+        print(scratch_build_code_linux_macos, file=code_file)
+
+if __name__ == "__main__":
+    main()