diff --git a/CMakeLists.txt b/CMakeLists.txt
index 89a3e53..2a79b53 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,9 @@
 cmake_minimum_required(VERSION 3.10)
+
+# Load the PSP platform configuration BEFORE project()
+set(CMAKE_SYSTEM_CMAKE_PLATFORM_PATH "${CMAKE_SOURCE_DIR}/cmake")
+include(${CMAKE_SYSTEM_CMAKE_PLATFORM_PATH}/PSP.cmake)
+
 project(OSLib C CXX ASM)
 
 # Set C and C++ standards
@@ -9,10 +14,6 @@ set(CMAKE_CXX_STANDARD 23)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS ON)
 
-# Load the PSP platform configuration
-set(CMAKE_SYSTEM_CMAKE_PLATFORM_PATH "${CMAKE_SOURCE_DIR}/cmake")
-include(${CMAKE_SYSTEM_CMAKE_PLATFORM_PATH}/PSP.cmake)
-
 # Set the output library
 set(TARGET_LIB osl)
 add_library(${TARGET_LIB} STATIC)
diff --git a/cmake/IMG.cmake b/cmake/IMG.cmake
index 4995d62..4a13ce7 100644
--- a/cmake/IMG.cmake
+++ b/cmake/IMG.cmake
@@ -38,9 +38,30 @@ endforeach()
 list(APPEND OSL_IMAGE_FORMATS_AVAILABLE ${OSL_IMAGE_FORMAT_LOADERS} ${OSL_IMAGE_FORMAT_WRITERS})
 list(REMOVE_DUPLICATES OSL_IMAGE_FORMATS_AVAILABLE)
 
+# Formats that should always use the repository's local implementation
+# (skip external find_package). Add names here (e.g. GIF) when the project
+# includes a bundled implementation that should take priority.
+if(NOT DEFINED FORCE_LOCAL_IMAGE_FORMATS)
+	set(FORCE_LOCAL_IMAGE_FORMATS GIF)
+endif()
+
 foreach(IMAGE_FORMAT ${OSL_IMAGE_FORMATS_AVAILABLE})
-	find_package(${IMAGE_FORMAT})
-	if(${IMAGE_FORMAT}_FOUND)
+	# If this format is forced to use the local implementation, skip find_package
+	list(FIND FORCE_LOCAL_IMAGE_FORMATS ${IMAGE_FORMAT} _is_forced)
+	if(NOT _is_forced EQUAL -1)
+		# Use local implementation (mark supported if loader/writer exists)
+		if(${IMAGE_FORMAT} IN_LIST OSL_IMAGE_FORMAT_LOADERS)
+			list(APPEND OSL_IMAGE_FORMATS_SUPPORTED ${IMAGE_FORMAT})
+			add_compile_definitions(-DOSL_IMAGE_LOADER_${IMAGE_FORMAT})
+		endif()
+		if(${IMAGE_FORMAT} IN_LIST OSL_IMAGE_FORMAT_WRITERS)
+			list(APPEND OSL_IMAGE_FORMATS_SUPPORTED ${IMAGE_FORMAT})
+			add_compile_definitions(-DOSL_IMAGE_WRITER_${IMAGE_FORMAT})
+		endif()
+	else()
+		find_package(${IMAGE_FORMAT})
+		if(${IMAGE_FORMAT}_FOUND)
+		# External package found (SDK or system) -> use it
 		list(APPEND OSL_IMAGE_FORMATS_SUPPORTED ${IMAGE_FORMAT})
 		if(${IMAGE_FORMAT} IN_LIST OSL_IMAGE_FORMAT_LOADERS)
 			add_compile_definitions(-DOSL_IMAGE_LOADER_${IMAGE_FORMAT})
@@ -50,9 +71,26 @@ foreach(IMAGE_FORMAT ${OSL_IMAGE_FORMATS_AVAILABLE})
 			add_compile_definitions(-DOSL_IMAGE_WRITER_${IMAGE_FORMAT})
 			include_directories(${${IMAGE_FORMAT}_INCLUDE_DIRS})
 		endif()
-	else()
-		list(REMOVE_ITEM OSL_IMAGE_FORMAT_WRITERS ${IMAGE_FORMAT})
-		list(REMOVE_ITEM OSL_IMAGE_FORMAT_LOADERS ${IMAGE_FORMAT})
+		else()
+			# No external package found. If we have a local implementation (source
+			# files under src/image/format), keep the loader/writer and mark the
+			# format as supported using the local code. Otherwise remove it.
+			set(_has_local_impl FALSE)
+			if(${IMAGE_FORMAT} IN_LIST OSL_IMAGE_FORMAT_LOADERS)
+				list(APPEND OSL_IMAGE_FORMATS_SUPPORTED ${IMAGE_FORMAT})
+				add_compile_definitions(-DOSL_IMAGE_LOADER_${IMAGE_FORMAT})
+				set(_has_local_impl TRUE)
+			endif()
+			if(${IMAGE_FORMAT} IN_LIST OSL_IMAGE_FORMAT_WRITERS)
+				list(APPEND OSL_IMAGE_FORMATS_SUPPORTED ${IMAGE_FORMAT})
+				add_compile_definitions(-DOSL_IMAGE_WRITER_${IMAGE_FORMAT})
+				set(_has_local_impl TRUE)
+			endif()
+			if(NOT _has_local_impl)
+				list(REMOVE_ITEM OSL_IMAGE_FORMAT_WRITERS ${IMAGE_FORMAT})
+				list(REMOVE_ITEM OSL_IMAGE_FORMAT_LOADERS ${IMAGE_FORMAT})
+			endif()
+		endif()
 	endif()
 endforeach()
 
@@ -64,4 +102,3 @@ foreach(IMAGE_FORMAT ${OSL_IMAGE_FORMAT_LOADERS})
 endforeach()
 
 message("-- Using ${OSL_IMAGE_FORMATS_SUPPORTED}")
-
diff --git a/cmake/PSP.cmake b/cmake/PSP.cmake
index 25046ec..42e30c3 100644
--- a/cmake/PSP.cmake
+++ b/cmake/PSP.cmake
@@ -30,6 +30,37 @@ execute_process(
     OUTPUT_STRIP_TRAILING_WHITESPACE
 )
 
+# Determine PSP root for includes/libs. Prefer psp-config output, fall back to PSPDEV env.
+if(PSPDIR)
+    set(PSPDEV_ROOT "${PSPDIR}")
+elseif(DEFINED ENV{PSPDEV})
+    set(PSPDEV_ROOT "$ENV{PSPDEV}/psp")
+endif()
+
+# When cross-compiling we want find_package/find_library to search the PSP SDK
+# first. Configure CMake search roots and modes so find_* will look into the
+# PSPDEV root for includes and libraries rather than the host system paths.
+if(PSPDEV_ROOT)
+    set(CMAKE_FIND_ROOT_PATH "${PSPDEV_ROOT};${PSPDEV_ROOT}/sdk" CACHE PATH "Search root for PSP cross build" FORCE)
+    set(CMAKE_SYSROOT "${PSPDEV_ROOT}" CACHE PATH "Sysroot for PSP cross-compilation" FORCE)
+    # Never search programs in the root path (we want host tools for executables)
+    set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+    # For libraries and includes, prefer only the root path when cross-compiling
+    set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+    set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
+else()
+    message(WARNING "PSPDEV not set: find_package may locate host system libraries instead of PSP SDK ones")
+endif()
+
+# Add PSP SDK to prefix path so find_package can locate CMake configs or modules under the SDK
+if(PSPDEV_ROOT)
+    list(APPEND CMAKE_PREFIX_PATH "${PSPDEV_ROOT}" "${PSPDEV_ROOT}/sdk")
+    # If the SDK provides pkgconfig files, prefer them for pkg-config based finders
+    if(EXISTS "${PSPDEV_ROOT}/lib/pkgconfig")
+        set(ENV{PKG_CONFIG_LIBDIR} "${PSPDEV_ROOT}/lib/pkgconfig")
+    endif()
+endif()
+
 # Set PSP compile flags
 add_compile_options(-G0 -Wall -Wextra -Wno-unused -Wno-strict-prototypes -Wno-missing-prototypes
 	-fno-strict-aliasing)
@@ -62,13 +93,23 @@ link_libraries(
     -lpng -ljpeg -lz -lm
 )
 
-# Set the path to the PSP SDK includes and libraries
-include_directories(
-    $ENV{PSPDEV}/psp/include
-    $ENV{PSPDEV}/psp/sdk/include
-)
-link_directories(
-    $ENV{PSPDEV}/psp/lib
-    $ENV{PSPDEV}/psp/sdk/lib
-)
-
+# Set the path to the PSP SDK includes and libraries (use PSPDEV_ROOT if available)
+if(PSPDEV_ROOT)
+    include_directories(
+        ${PSPDEV_ROOT}/include
+        ${PSPDEV_ROOT}/sdk/include
+    )
+    link_directories(
+        ${PSPDEV_ROOT}/lib
+        ${PSPDEV_ROOT}/sdk/lib
+    )
+else()
+    include_directories(
+        $ENV{PSPDEV}/psp/include
+        $ENV{PSPDEV}/psp/sdk/include
+    )
+    link_directories(
+        $ENV{PSPDEV}/psp/lib
+        $ENV{PSPDEV}/psp/sdk/lib
+    )
+endif()