From d1b473483d10b68eeec115144d1429bb5971e1cb Mon Sep 17 00:00:00 2001
From: Grzegorz Swiderski <grzegorz.swiderski@nordicsemi.no>
Date: Fri, 7 Jun 2024 11:55:31 +0200
Subject: [PATCH 1/2] scripts: gen_dts_cmake: Support variable target name in
 dts.cmake

Instead of hardcoding the name `devicetree_target`, we can update the
generated `dts.cmake` to accept `DEVICETREE_TARGET` as input variable.
This will become useful in multi-image builds, where we would like to
process multiple devicetrees.

Signed-off-by: Grzegorz Swiderski <grzegorz.swiderski@nordicsemi.no>
---
 cmake/modules/dts.cmake      |  2 ++
 scripts/dts/gen_dts_cmake.py | 21 ++++++++++-----------
 2 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/cmake/modules/dts.cmake b/cmake/modules/dts.cmake
index ec0999d366b9..6bdce4aaa20e 100644
--- a/cmake/modules/dts.cmake
+++ b/cmake/modules/dts.cmake
@@ -117,6 +117,8 @@ set(GEN_DTS_CMAKE_SCRIPT        ${DT_SCRIPTS}/gen_dts_cmake.py)
 # The generated information itself, which we include() after
 # creating it.
 set(DTS_CMAKE                   ${PROJECT_BINARY_DIR}/dts.cmake)
+# The CMake target to be initialized by including ${DTS_CMAKE}.
+set(DEVICETREE_TARGET           devicetree_target)
 
 # The location of a file containing known vendor prefixes, relative to
 # each element of DTS_ROOT. Users can define their own in their own
diff --git a/scripts/dts/gen_dts_cmake.py b/scripts/dts/gen_dts_cmake.py
index 6fa4a3478802..653910cbf8d0 100755
--- a/scripts/dts/gen_dts_cmake.py
+++ b/scripts/dts/gen_dts_cmake.py
@@ -11,12 +11,13 @@
 
 The generated CMake file looks like this:
 
-  add_custom_target(devicetree_target)
-  set_target_properties(devicetree_target PROPERTIES
+  add_custom_target(${DEVICETREE_TARGET})
+  set_target_properties(${DEVICETREE_TARGET} PROPERTIES
                         "DT_PROP|/soc|compatible" "vnd,soc;")
   ...
 
-It defines a special CMake target, and saves various values in the
+It takes an input variable - DEVICETREE_TARGET - and creates a special
+CMake target with this name, which will contain various values in the
 devicetree as CMake target properties.
 
 Be careful:
@@ -154,15 +155,13 @@ def main():
         cmake_comp = f'DT_COMP|{comp}'
         cmake_props.append(f'"{cmake_comp}" "{cmake_path}"')
 
+    cmake_props = map(
+        'set_target_properties(${{DEVICETREE_TARGET}} PROPERTIES {})'.format,
+        cmake_props
+    )
     with open(args.cmake_out, "w", encoding="utf-8") as cmake_file:
-        print('add_custom_target(devicetree_target)', file=cmake_file)
-        print(file=cmake_file)
-
-        for prop in cmake_props:
-            print(
-                f'set_target_properties(devicetree_target PROPERTIES {prop})',
-                file=cmake_file
-            )
+        print('add_custom_target(${DEVICETREE_TARGET})\n', *cmake_props,
+              sep='\n', file=cmake_file)
 
 
 if __name__ == "__main__":

From f6de4d0593b14352e8f86f78ea32757150560123 Mon Sep 17 00:00:00 2001
From: Grzegorz Swiderski <grzegorz.swiderski@nordicsemi.no>
Date: Fri, 7 Jun 2024 11:55:31 +0200
Subject: [PATCH 2/2] sysbuild: dts: Introduce sysbuild_dt_* API

Add new functions to `sysbuild_extensions.cmake`, which will mirror the
familiar dt_* API from Zephyr `extensions.cmake`. For example:

   dt_nodelabel(<var> NODELABEL <label>)

gets the following sysbuild counterpart, with one extra argument:

   sysbuild_dt_nodelabel(<var> IMAGE <image> NODELABEL <label>)

This API allows sysbuild to retrieve devicetree information for a given
<image>, only after its respective `ExternalZephyrProject_Cmake()` call.

This works by importing the generated `dts.cmake` files from each
image's build directory, and creating multiple CMake targets to hold the
generated properties - much like how the `CMakeCache.txt` and `.config`
are also imported to be used by the related `sysbuild_get()` function.

The dt_* API itself also has to be updated, in order to read properties
from a variable `DEVICETREE_TARGET` set in the parent scope.

Signed-off-by: Grzegorz Swiderski <grzegorz.swiderski@nordicsemi.no>
---
 cmake/modules/extensions.cmake                | 71 +++++++++++++---
 .../cmake/modules/sysbuild_extensions.cmake   | 85 +++++++++++++++++++
 2 files changed, 144 insertions(+), 12 deletions(-)

diff --git a/cmake/modules/extensions.cmake b/cmake/modules/extensions.cmake
index 4d8422a3ced5..b9812d843795 100644
--- a/cmake/modules/extensions.cmake
+++ b/cmake/modules/extensions.cmake
@@ -3611,6 +3611,9 @@ endfunction()
 #   alias at the beginning of a path interchangeably with the full
 #   path to the aliased node in these functions. The usage comments
 #   will make this clear in each case.
+#
+# - Each of these methods also has a sysbuild_dt_* counterpart.
+#   See share/sysbuild/cmake/modules/sysbuild_extensions.cmake.
 
 # Usage:
 #   dt_nodelabel(<var> NODELABEL <label>)
@@ -3638,6 +3641,10 @@ endfunction()
 # NODELABEL <label>  : Node label
 # REQUIRED           : Generate a fatal error if the node-label is not found
 function(dt_nodelabel var)
+  if(NOT DEFINED DEVICETREE_TARGET OR NOT TARGET "${DEVICETREE_TARGET}")
+    message(FATAL_ERROR "dt_nodelabel(${ARGV0} ...) devicetree is not available.")
+  endif()
+
   set(options "REQUIRED")
   set(req_single_args "NODELABEL")
   cmake_parse_arguments(DT_LABEL "${options}" "${req_single_args}" "" ${ARGN})
@@ -3654,7 +3661,7 @@ function(dt_nodelabel var)
     endif()
   endforeach()
 
-  get_target_property(${var} devicetree_target "DT_NODELABEL|${DT_LABEL_NODELABEL}")
+  get_target_property(${var} "${DEVICETREE_TARGET}" "DT_NODELABEL|${DT_LABEL_NODELABEL}")
   if(${${var}} STREQUAL ${var}-NOTFOUND)
     if(DT_LABEL_REQUIRED)
       message(FATAL_ERROR "required nodelabel not found: ${DT_LABEL_NODELABEL}")
@@ -3686,6 +3693,10 @@ endfunction()
 # PROPERTY <prop> : The alias to check
 # REQUIRED        : Generate a fatal error if the alias is not found
 function(dt_alias var)
+  if(NOT DEFINED DEVICETREE_TARGET OR NOT TARGET "${DEVICETREE_TARGET}")
+    message(FATAL_ERROR "dt_alias(${ARGV0} ...) devicetree is not available.")
+  endif()
+
   set(options "REQUIRED")
   set(req_single_args "PROPERTY")
   cmake_parse_arguments(DT_ALIAS "${options}" "${req_single_args}" "" ${ARGN})
@@ -3702,7 +3713,7 @@ function(dt_alias var)
     endif()
   endforeach()
 
-  get_target_property(${var} devicetree_target "DT_ALIAS|${DT_ALIAS_PROPERTY}")
+  get_target_property(${var} "${DEVICETREE_TARGET}" "DT_ALIAS|${DT_ALIAS_PROPERTY}")
   if(${${var}} STREQUAL ${var}-NOTFOUND)
     if(DT_ALIAS_REQUIRED)
       message(FATAL_ERROR "required alias not found: ${DT_ALIAS_PROPERTY}")
@@ -3730,6 +3741,10 @@ endfunction()
 # <var>       : Return variable where the check result will be returned
 # PATH <path> : Node path
 function(dt_node_exists var)
+  if(NOT DEFINED DEVICETREE_TARGET OR NOT TARGET "${DEVICETREE_TARGET}")
+    message(FATAL_ERROR "dt_node_exists(${ARGV0} ...) devicetree is not available.")
+  endif()
+
   set(req_single_args "PATH")
   cmake_parse_arguments(DT_NODE "" "${req_single_args}" "" ${ARGN})
 
@@ -3775,6 +3790,10 @@ endfunction()
 # PATH <path>     : Node path
 # STATUS <status> : Status to check
 function(dt_node_has_status var)
+  if(NOT DEFINED DEVICETREE_TARGET OR NOT TARGET "${DEVICETREE_TARGET}")
+    message(FATAL_ERROR "dt_node_has_status(${ARGV0} ...) devicetree is not available.")
+  endif()
+
   set(req_single_args "PATH;STATUS")
   cmake_parse_arguments(DT_NODE "" "${req_single_args}" "" ${ARGN})
 
@@ -3861,6 +3880,10 @@ endfunction()
 # INDEX <idx>    : Optional index when retrieving a value in an array property
 # REQUIRED       : Generate a fatal error if the property is not found
 function(dt_prop var)
+  if(NOT DEFINED DEVICETREE_TARGET OR NOT TARGET "${DEVICETREE_TARGET}")
+    message(FATAL_ERROR "dt_prop(${ARGV0} ...) devicetree is not available.")
+  endif()
+
   set(options "REQUIRED")
   set(req_single_args "PATH;PROPERTY")
   set(single_args "INDEX")
@@ -3879,7 +3902,7 @@ function(dt_prop var)
   endforeach()
 
   dt_path_internal(canonical "${DT_PROP_PATH}")
-  get_property(exists TARGET devicetree_target
+  get_property(exists TARGET "${DEVICETREE_TARGET}"
       PROPERTY "DT_PROP|${canonical}|${DT_PROP_PROPERTY}"
       SET
   )
@@ -3892,7 +3915,7 @@ function(dt_prop var)
     return()
   endif()
 
-  get_target_property(val devicetree_target
+  get_target_property(val "${DEVICETREE_TARGET}"
       "DT_PROP|${canonical}|${DT_PROP_PROPERTY}"
   )
 
@@ -3921,6 +3944,10 @@ endfunction()
 # INDEX <idx>            : Optional index when retrieving a value in an array property
 
 function(dt_comp_path var)
+  if(NOT DEFINED DEVICETREE_TARGET OR NOT TARGET "${DEVICETREE_TARGET}")
+    message(FATAL_ERROR "dt_comp_path(${ARGV0} ...) devicetree is not available.")
+  endif()
+
   set(req_single_args "COMPATIBLE")
   set(single_args "INDEX")
   cmake_parse_arguments(DT_COMP "" "${req_single_args};${single_args}" "" ${ARGN})
@@ -3937,7 +3964,7 @@ function(dt_comp_path var)
     endif()
   endforeach()
 
-  get_property(exists TARGET devicetree_target
+  get_property(exists TARGET "${DEVICETREE_TARGET}"
       PROPERTY "DT_COMP|${DT_COMP_COMPATIBLE}"
       SET
   )
@@ -3947,7 +3974,7 @@ function(dt_comp_path var)
     return()
   endif()
 
-  get_target_property(val devicetree_target
+  get_target_property(val "${DEVICETREE_TARGET}"
       "DT_COMP|${DT_COMP_COMPATIBLE}"
   )
 
@@ -3976,6 +4003,10 @@ endfunction()
 # <var>          : Return variable where the property value will be stored
 # PATH <path>    : Node path
 function(dt_num_regs var)
+  if(NOT DEFINED DEVICETREE_TARGET OR NOT TARGET "${DEVICETREE_TARGET}")
+    message(FATAL_ERROR "dt_num_regs(${ARGV0} ...) devicetree is not available.")
+  endif()
+
   set(req_single_args "PATH")
   cmake_parse_arguments(DT_REG "" "${req_single_args}" "" ${ARGN})
 
@@ -3992,7 +4023,7 @@ function(dt_num_regs var)
   endforeach()
 
   dt_path_internal(canonical "${DT_REG_PATH}")
-  get_target_property(${var} devicetree_target "DT_REG|${canonical}|NUM")
+  get_target_property(${var} "${DEVICETREE_TARGET}" "DT_REG|${canonical}|NUM")
 
   set(${var} ${${var}} PARENT_SCOPE)
 endfunction()
@@ -4022,6 +4053,10 @@ endfunction()
 # INDEX <idx>    : Register block index number
 # NAME <name>    : Register block name
 function(dt_reg_addr var)
+  if(NOT DEFINED DEVICETREE_TARGET OR NOT TARGET "${DEVICETREE_TARGET}")
+    message(FATAL_ERROR "dt_reg_addr(${ARGV0} ...) devicetree is not available.")
+  endif()
+
   set(req_single_args "PATH")
   set(single_args "INDEX;NAME")
   cmake_parse_arguments(DT_REG "" "${req_single_args};${single_args}" "" ${ARGN})
@@ -4051,7 +4086,7 @@ function(dt_reg_addr var)
   endif()
 
   dt_path_internal(canonical "${DT_REG_PATH}")
-  get_target_property(${var}_list devicetree_target "DT_REG|${canonical}|ADDR")
+  get_target_property(${var}_list "${DEVICETREE_TARGET}" "DT_REG|${canonical}|ADDR")
 
   list(GET ${var}_list ${DT_REG_INDEX} ${var})
 
@@ -4082,6 +4117,10 @@ endfunction()
 # INDEX <idx>    : Register block index number
 # NAME <name>    : Register block name
 function(dt_reg_size var)
+  if(NOT DEFINED DEVICETREE_TARGET OR NOT TARGET "${DEVICETREE_TARGET}")
+    message(FATAL_ERROR "dt_reg_size(${ARGV0} ...) devicetree is not available.")
+  endif()
+
   set(req_single_args "PATH")
   set(single_args "INDEX;NAME")
   cmake_parse_arguments(DT_REG "" "${req_single_args};${single_args}" "" ${ARGN})
@@ -4111,7 +4150,7 @@ function(dt_reg_size var)
   endif()
 
   dt_path_internal(canonical "${DT_REG_PATH}")
-  get_target_property(${var}_list devicetree_target "DT_REG|${canonical}|SIZE")
+  get_target_property(${var}_list "${DEVICETREE_TARGET}" "DT_REG|${canonical}|SIZE")
 
   list(GET ${var}_list ${DT_REG_INDEX} ${var})
 
@@ -4159,6 +4198,10 @@ endfunction()
 # <var>           : Return variable
 # PROPERTY <prop> : Chosen property
 function(dt_has_chosen var)
+  if(NOT DEFINED DEVICETREE_TARGET OR NOT TARGET "${DEVICETREE_TARGET}")
+    message(FATAL_ERROR "dt_has_chosen(${ARGV0} ...) devicetree is not available.")
+  endif()
+
   set(req_single_args "PROPERTY")
   cmake_parse_arguments(DT_CHOSEN "" "${req_single_args}" "" ${ARGN})
 
@@ -4174,7 +4217,7 @@ function(dt_has_chosen var)
     endif()
   endforeach()
 
-  get_target_property(exists devicetree_target "DT_CHOSEN|${DT_CHOSEN_PROPERTY}")
+  get_target_property(exists "${DEVICETREE_TARGET}" "DT_CHOSEN|${DT_CHOSEN_PROPERTY}")
 
   if(${exists} STREQUAL exists-NOTFOUND)
     set(${var} FALSE PARENT_SCOPE)
@@ -4194,6 +4237,10 @@ endfunction()
 # <var>           : Return variable where the node path will be stored
 # PROPERTY <prop> : Chosen property
 function(dt_chosen var)
+  if(NOT DEFINED DEVICETREE_TARGET OR NOT TARGET "${DEVICETREE_TARGET}")
+    message(FATAL_ERROR "dt_chosen(${ARGV0} ...) devicetree is not available.")
+  endif()
+
   set(req_single_args "PROPERTY")
   cmake_parse_arguments(DT_CHOSEN "" "${req_single_args}" "" ${ARGN})
 
@@ -4209,7 +4256,7 @@ function(dt_chosen var)
     endif()
   endforeach()
 
-  get_target_property(${var} devicetree_target "DT_CHOSEN|${DT_CHOSEN_PROPERTY}")
+  get_target_property(${var} "${DEVICETREE_TARGET}" "DT_CHOSEN|${DT_CHOSEN_PROPERTY}")
 
   if(${${var}} STREQUAL ${var}-NOTFOUND)
     set(${var} PARENT_SCOPE)
@@ -4281,7 +4328,7 @@ endfunction()
 # to an existing node. Set it to FALSE otherwise. See
 # dt_path_internal for a definition and examples of 'canonical' paths.
 function(dt_path_internal_exists var path)
-  get_target_property(path_prop devicetree_target "DT_NODE|${path}")
+  get_target_property(path_prop "${DEVICETREE_TARGET}" "DT_NODE|${path}")
   if (path_prop)
     set(${var} TRUE PARENT_SCOPE)
   else()
diff --git a/share/sysbuild/cmake/modules/sysbuild_extensions.cmake b/share/sysbuild/cmake/modules/sysbuild_extensions.cmake
index c1b2513d192f..0853535a9114 100644
--- a/share/sysbuild/cmake/modules/sysbuild_extensions.cmake
+++ b/share/sysbuild/cmake/modules/sysbuild_extensions.cmake
@@ -503,6 +503,8 @@ function(ExternalZephyrProject_Cmake)
   endif()
   load_cache(IMAGE ${ZCMAKE_APPLICATION} BINARY_DIR ${BINARY_DIR})
   import_kconfig(CONFIG_ ${BINARY_DIR}/zephyr/.config TARGET ${ZCMAKE_APPLICATION})
+  set(DEVICETREE_TARGET ${ZCMAKE_APPLICATION}_devicetree_target)
+  include(${BINARY_DIR}/zephyr/dts.cmake)
 
   # This custom target informs CMake how the BYPRODUCTS are generated if a target
   # depends directly on the BYPRODUCT instead of depending on the image target.
@@ -750,3 +752,86 @@ function(sysbuild_images_order variable dependency_type)
   topological_sort(TARGETS ${SIS_IMAGES} PROPERTY_NAME ${property_name} RESULT sorted)
   set(${variable} ${sorted} PARENT_SCOPE)
 endfunction()
+
+# Internal macro for defining the sysbuild_dt_* CMake extensions, used to
+# retrieve devicetree information from a Zephyr based build system.
+#
+# It takes a dt_* function <name> and adds common wrapper code, which
+# adds an `IMAGE` argument to select the devicetree of a given <image>,
+# and forwards all other arguments to the original function, including
+# the sole return variable <var> - a common trait of the dt_* API.
+#
+# For additional documentation of each dt_* CMake extension,
+# see section 4.1. of cmake/modules/extensions.cmake.
+#
+macro(sysbuild_dt_function name)
+  function(sysbuild_${name} var)
+    cmake_parse_arguments(PARSE_ARGV 1 SBDT "" "IMAGE" "")
+    zephyr_check_arguments_required_all("sysbuild_${name}" SBDT IMAGE)
+
+    set(DEVICETREE_TARGET ${SBDT_IMAGE}_devicetree_target)
+    if(NOT TARGET ${SBDT_IMAGE} OR NOT TARGET ${DEVICETREE_TARGET})
+      message(FATAL_ERROR "sysbuild_${name}(...) image '${SBDT_IMAGE}' "
+                          "does not exist or its devicetree is not loaded yet"
+      )
+    endif()
+
+    cmake_language(CALL ${name} ${var} ${SBDT_UNPARSED_ARGUMENTS})
+    set(${var} "${${var}}" PARENT_SCOPE)
+  endfunction()
+endmacro()
+
+# Usage:
+#   sysbuild_dt_nodelabel(<var> IMAGE <image> NODELABEL <label>)
+#
+sysbuild_dt_function(dt_nodelabel)
+
+# Usage:
+#   sysbuild_dt_alias(<var> IMAGE <image> PROPERTY <prop>)
+#
+sysbuild_dt_function(dt_alias)
+
+# Usage:
+#   sysbuild_dt_node_exists(<var> IMAGE <image> PATH <path>)
+#
+sysbuild_dt_function(dt_node_exists)
+
+# Usage:
+#   sysbuild_dt_node_has_status(<var> IMAGE <image> PATH <path> STATUS <status>)
+#
+sysbuild_dt_function(dt_node_has_status)
+
+# Usage:
+#   sysbuild_dt_prop(<var> IMAGE <image> PATH <path> PROPERTY <prop> [INDEX <idx>])
+#
+sysbuild_dt_function(dt_prop)
+
+# Usage:
+#   sysbuild_dt_comp_path(<var> IMAGE <image> COMPATIBLE <compatible> [INDEX <idx>])
+#
+sysbuild_dt_function(dt_comp_path)
+
+# Usage:
+#   sysbuild_dt_num_regs(<var> IMAGE <image> PATH <path>)
+#
+sysbuild_dt_function(dt_num_regs)
+
+# Usage:
+#   sysbuild_dt_reg_addr(<var> IMAGE <image> PATH <path> [INDEX <idx>] [NAME <name>])
+#
+sysbuild_dt_function(dt_reg_addr)
+
+# Usage:
+#   sysbuild_dt_reg_size(<var> IMAGE <image> PATH <path> [INDEX <idx>] [NAME <name>])
+#
+sysbuild_dt_function(dt_reg_size)
+
+# Usage:
+#   sysbuild_dt_has_chosen(<var> IMAGE <image> PROPERTY <prop>)
+#
+sysbuild_dt_function(dt_has_chosen)
+
+# Usage:
+#   sysbuild_dt_chosen(<var> IMAGE <image> PROPERTY <prop>)
+#
+sysbuild_dt_function(dt_chosen)