From 9e950dc32acf426361c0f6554e128e5ebba190f5 Mon Sep 17 00:00:00 2001
From: Keith Packard <keithp@keithp.com>
Date: Thu, 31 Jul 2025 13:52:18 -0700
Subject: [PATCH] gnu: Add legacy Zephyr compatibility

In setup.sh, add option to create symlinks from gnu/ so that
paths match previous SDK versions.

In Zephyr-sdkConfig.cmake, set ZEPHYR_TOOLCHAIN_VARIANT to zephyr/gnu
only when Zephyr sets ZEPHYR_TOOLCHAIN_VARIANT_COMPILER_SUPPORT before
finding the SDK module. This will require a change to Zephyr, which is
unfortunate. Ideally, we'd use some existing mechanism to detect when to
make this switch.

Signed-off-by: Keith Packard <keithp@keithp.com>
---
 cmake/Zephyr-sdkConfig.cmake |  6 +++++-
 scripts/template_setup_posix | 14 ++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/cmake/Zephyr-sdkConfig.cmake b/cmake/Zephyr-sdkConfig.cmake
index e9662d5e..8104c43f 100644
--- a/cmake/Zephyr-sdkConfig.cmake
+++ b/cmake/Zephyr-sdkConfig.cmake
@@ -13,7 +13,11 @@ get_filename_component(ZEPHYR_SDK_INSTALL_DIR ${CMAKE_CURRENT_LIST_DIR}/.. ABSOL
 set(ZEPHYR_SDK_INSTALL_DIR ${ZEPHYR_SDK_INSTALL_DIR})
 
 if(NOT DEFINED ZEPHYR_TOOLCHAIN_VARIANT)
-  set(ZEPHYR_TOOLCHAIN_VARIANT "zephyr/gnu")
+  if(DEFINED ZEPHYR_TOOLCHAIN_VARIANT_COMPILER_SUPPORT)
+    set(ZEPHYR_TOOLCHAIN_VARIANT "zephyr/gnu")
+  else()
+    set(ZEPHYR_TOOLCHAIN_VARIANT "zephyr")
+  endif()
 endif()
 
 # Those are CMake package parameters.
diff --git a/scripts/template_setup_posix b/scripts/template_setup_posix
index d680bf85..812bd75f 100644
--- a/scripts/template_setup_posix
+++ b/scripts/template_setup_posix
@@ -69,6 +69,7 @@ usage()
   echo "     all               Install all GNU toolchains"
   echo "  -l                   Install LLVM toolchain"
   echo "  -h                   Install host tools"
+  echo "  -o                   Old zephyr version compatibility"
   echo "  -c                   Register Zephyr SDK CMake package"
   echo
   echo "Supported GNU Toolchains:"
@@ -117,6 +118,8 @@ user_prompt()
   # Environment Configurations
   ask_yn "Register Zephyr SDK CMake package" && do_cmake_pkg="y"
 
+  ask_yn "Old zephyr version compatibility" && do_old_zephyr="y"
+
   echo
 }
 
@@ -159,6 +162,9 @@ else
       -c)
         do_cmake_pkg="y"
         ;;
+      -o)
+	do_old_zephyr="y"
+	;;
       '-?')
         usage
         exit 0
@@ -301,6 +307,14 @@ if [ "${do_cmake_pkg}" = "y" ]; then
   echo
 fi
 
+# Create compatibility links for old Zephyr versions
+if [ "${do_old_zephyr}" = "y" ]; then
+  echo "Creating links for old Zephyr compatibility ..."
+  ln -sr gnu/* . || assert_rc "ERROR: Creating toolchain links" 50
+  ln -sr cmake/zephyr/gnu/* cmake/zephyr || assert_rc "ERROR: Creating cmake links" 50
+  echo
+fi
+
 echo "All done."
 if [ "${interactive}" = "y" ]; then
   read -n 1 -s -r -p "Press any key to exit ..."