diff --git a/CMakeLists.txt b/CMakeLists.txt
index 16bc07ab7..29f83eb7e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -33,6 +33,12 @@ option(OT_BUILD_EXECUTABLES "Build executables" ON)
 option(OT_BUILTIN_MBEDTLS "Enable builtin mbedTLS" ON)
 option(OT_COVERAGE "enable coverage" OFF)
 
+include(TestBigEndian)
+TEST_BIG_ENDIAN(OT_BIG_ENDIAN)
+if(OT_BIG_ENDIAN)
+    list(APPEND OT_PRIVATE_DEFINES "BYTE_ORDER_BIG_ENDIAN=1")
+endif()
+
 include("${PROJECT_SOURCE_DIR}/etc/cmake/checks.cmake")
 include("${PROJECT_SOURCE_DIR}/etc/cmake/options.cmake")
 include("${PROJECT_SOURCE_DIR}/etc/cmake/functions.cmake")
diff --git a/etc/cmake/options.cmake b/etc/cmake/options.cmake
index da1b9e7ea..bd16a3ce1 100644
--- a/etc/cmake/options.cmake
+++ b/etc/cmake/options.cmake
@@ -31,11 +31,6 @@ if(OT_BACKBONE_ROUTER)
     list(APPEND OT_PRIVATE_DEFINES "OPENTHREAD_CONFIG_BACKBONE_ROUTER_ENABLE=1")
 endif()
 
-option(OT_BIG_ENDIAN "host platform uses big-endian byte order")
-if(OT_BIG_ENDIAN)
-    list(APPEND OT_PRIVATE_DEFINES "BYTE_ORDER_BIG_ENDIAN=1")
-endif()
-
 option(OT_BORDER_AGENT "enable border agent support")
 if(OT_BORDER_AGENT)
     list(APPEND OT_PRIVATE_DEFINES "OPENTHREAD_CONFIG_BORDER_AGENT_ENABLE=1")
diff --git a/examples/platforms/cc1352/CMakeLists.txt b/examples/platforms/cc1352/CMakeLists.txt
index 6b96df719..a0f350503 100644
--- a/examples/platforms/cc1352/CMakeLists.txt
+++ b/examples/platforms/cc1352/CMakeLists.txt
@@ -78,6 +78,7 @@ target_link_options(openthread-cc1352
 )
 target_link_options(openthread-cc1352
     PUBLIC
+        -Wl,--gc-sections
         -Wl,-Map=$<TARGET_PROPERTY:NAME>.map
 )
 
diff --git a/examples/platforms/cc1352/arm-none-eabi.cmake b/examples/platforms/cc1352/arm-none-eabi.cmake
index 334ad6387..c2789c3a5 100644
--- a/examples/platforms/cc1352/arm-none-eabi.cmake
+++ b/examples/platforms/cc1352/arm-none-eabi.cmake
@@ -39,14 +39,12 @@ set(COMMON_C_FLAGS                 "-mcpu=cortex-m4 -march=armv7e-m -mfloat-abi=
 set(CMAKE_C_FLAGS                  "${COMMON_C_FLAGS} -std=gnu99")
 set(CMAKE_CXX_FLAGS                "${COMMON_C_FLAGS} -fno-exceptions -fno-rtti")
 set(CMAKE_ASM_FLAGS                "${COMMON_C_FLAGS}")
-set(CMAKE_EXE_LINKER_FLAGS         "${COMMON_C_FLAGS} -nostartfiles -specs=nano.specs -specs=nosys.specs -Wl,--gc-sections -Wl,-Map=map.map")
+set(CMAKE_EXE_LINKER_FLAGS_INIT    "${COMMON_C_FLAGS} -nostartfiles -specs=nano.specs -specs=nosys.specs")
 
 set(CMAKE_C_FLAGS_DEBUG            "-Og -g")
 set(CMAKE_CXX_FLAGS_DEBUG          "-Og -g")
 set(CMAKE_ASM_FLAGS_DEBUG          "-g")
-set(CMAKE_EXE_LINKER_FLAGS_DEBUG   "")
 
 set(CMAKE_C_FLAGS_RELEASE          "-Os")
 set(CMAKE_CXX_FLAGS_RELEASE        "-Os")
 set(CMAKE_ASM_FLAGS_RELEASE        "")
-set(CMAKE_EXE_LINKER_FLAGS_RELEASE "")
diff --git a/examples/platforms/cc2538/CMakeLists.txt b/examples/platforms/cc2538/CMakeLists.txt
index aeb17c4d6..04dec2f6d 100644
--- a/examples/platforms/cc2538/CMakeLists.txt
+++ b/examples/platforms/cc2538/CMakeLists.txt
@@ -59,7 +59,7 @@ set_property(TARGET openthread-cc2538 PROPERTY C_STANDARD 99)
 
 target_link_libraries(openthread-cc2538 PRIVATE openthread-platform-utils)
 target_link_options(openthread-cc2538 PUBLIC -T${PROJECT_SOURCE_DIR}/examples/platforms/cc2538/cc2538.ld)
-target_link_options(openthread-cc2538 PUBLIC -Wl,-Map=$<TARGET_PROPERTY:NAME>.map)
+target_link_options(openthread-cc2538 PUBLIC -Wl,--gc-sections -Wl,-Map=$<TARGET_PROPERTY:NAME>.map)
 
 target_compile_definitions(openthread-cc2538
     PUBLIC
diff --git a/examples/platforms/cc2538/arm-none-eabi.cmake b/examples/platforms/cc2538/arm-none-eabi.cmake
index 3dfbb5f55..dc06caed5 100644
--- a/examples/platforms/cc2538/arm-none-eabi.cmake
+++ b/examples/platforms/cc2538/arm-none-eabi.cmake
@@ -39,14 +39,12 @@ set(COMMON_C_FLAGS                 "-mthumb -fno-builtin -Wall -fdata-sections -
 set(CMAKE_C_FLAGS                  "${COMMON_C_FLAGS} -std=gnu99")
 set(CMAKE_CXX_FLAGS                "${COMMON_C_FLAGS} -fno-exceptions -fno-rtti")
 set(CMAKE_ASM_FLAGS                "${COMMON_C_FLAGS}")
-set(CMAKE_EXE_LINKER_FLAGS         "${COMMON_C_FLAGS} -Wl,--gc-sections -specs=nano.specs -specs=nosys.specs -nostartfiles")
+set(CMAKE_EXE_LINKER_FLAGS_INIT    "${COMMON_C_FLAGS} -specs=nano.specs -specs=nosys.specs -nostartfiles")
 
 set(CMAKE_C_FLAGS_DEBUG            "-Og -g")
 set(CMAKE_CXX_FLAGS_DEBUG          "-Og -g")
 set(CMAKE_ASM_FLAGS_DEBUG          "-g")
-set(CMAKE_EXE_LINKER_FLAGS_DEBUG   "")
 
 set(CMAKE_C_FLAGS_RELEASE          "-Os")
 set(CMAKE_CXX_FLAGS_RELEASE        "-Os")
 set(CMAKE_ASM_FLAGS_RELEASE        "")
-set(CMAKE_EXE_LINKER_FLAGS_RELEASE "")
diff --git a/examples/platforms/cc2650/CMakeLists.txt b/examples/platforms/cc2650/CMakeLists.txt
index 2db69e5fc..c731eecb0 100644
--- a/examples/platforms/cc2650/CMakeLists.txt
+++ b/examples/platforms/cc2650/CMakeLists.txt
@@ -77,6 +77,7 @@ target_link_libraries(openthread-cc2650
 
 target_link_options(openthread-cc2650
     PUBLIC
+        -Wl,--gc-sections
         -Wl,-Map=$<TARGET_PROPERTY:NAME>.map
 )
 
diff --git a/examples/platforms/cc2650/arm-none-eabi.cmake b/examples/platforms/cc2650/arm-none-eabi.cmake
index 9612baace..c889e39f0 100644
--- a/examples/platforms/cc2650/arm-none-eabi.cmake
+++ b/examples/platforms/cc2650/arm-none-eabi.cmake
@@ -39,14 +39,12 @@ set(COMMON_C_FLAGS                 "-mthumb -fdata-sections -ffunction-sections
 set(CMAKE_C_FLAGS                  "${COMMON_C_FLAGS} -std=gnu99")
 set(CMAKE_CXX_FLAGS                "${COMMON_C_FLAGS} -fno-exceptions -fno-rtti")
 set(CMAKE_ASM_FLAGS                "${COMMON_C_FLAGS}")
-set(CMAKE_EXE_LINKER_FLAGS         "${COMMON_C_FLAGS} -Wl,--gc-sections -specs=nano.specs -specs=nosys.specs -nostartfiles")
+set(CMAKE_EXE_LINKER_FLAGS_INIT    "${COMMON_C_FLAGS} -specs=nano.specs -specs=nosys.specs -nostartfiles")
 
 set(CMAKE_C_FLAGS_DEBUG            "-Og -g")
 set(CMAKE_CXX_FLAGS_DEBUG          "-Og -g")
 set(CMAKE_ASM_FLAGS_DEBUG          "-g")
-set(CMAKE_EXE_LINKER_FLAGS_DEBUG   "")
 
 set(CMAKE_C_FLAGS_RELEASE          "-Os")
 set(CMAKE_CXX_FLAGS_RELEASE        "-Os")
 set(CMAKE_ASM_FLAGS_RELEASE        "")
-set(CMAKE_EXE_LINKER_FLAGS_RELEASE "")
diff --git a/examples/platforms/cc2652/CMakeLists.txt b/examples/platforms/cc2652/CMakeLists.txt
index e52a6ee19..447e50c7b 100644
--- a/examples/platforms/cc2652/CMakeLists.txt
+++ b/examples/platforms/cc2652/CMakeLists.txt
@@ -75,6 +75,7 @@ target_link_libraries(openthread-cc2652
 target_link_options(openthread-cc2652
     PUBLIC
         -T${PROJECT_SOURCE_DIR}/third_party/ti/devices/cc13x2_cc26x2/linker_files/cc26x2r1f.lds
+        -Wl,--gc-sections
         -Wl,-Map=$<TARGET_PROPERTY:NAME>.map
 )
 
diff --git a/examples/platforms/cc2652/arm-none-eabi.cmake b/examples/platforms/cc2652/arm-none-eabi.cmake
index 334ad6387..bd81b366a 100644
--- a/examples/platforms/cc2652/arm-none-eabi.cmake
+++ b/examples/platforms/cc2652/arm-none-eabi.cmake
@@ -39,14 +39,12 @@ set(COMMON_C_FLAGS                 "-mcpu=cortex-m4 -march=armv7e-m -mfloat-abi=
 set(CMAKE_C_FLAGS                  "${COMMON_C_FLAGS} -std=gnu99")
 set(CMAKE_CXX_FLAGS                "${COMMON_C_FLAGS} -fno-exceptions -fno-rtti")
 set(CMAKE_ASM_FLAGS                "${COMMON_C_FLAGS}")
-set(CMAKE_EXE_LINKER_FLAGS         "${COMMON_C_FLAGS} -nostartfiles -specs=nano.specs -specs=nosys.specs -Wl,--gc-sections -Wl,-Map=map.map")
+set(CMAKE_EXE_LINKER_FLAGS_INIT    "${COMMON_C_FLAGS} -nostartfiles -specs=nano.specs -specs=nosys.specs -Wl,-Map=map.map")
 
 set(CMAKE_C_FLAGS_DEBUG            "-Og -g")
 set(CMAKE_CXX_FLAGS_DEBUG          "-Og -g")
 set(CMAKE_ASM_FLAGS_DEBUG          "-g")
-set(CMAKE_EXE_LINKER_FLAGS_DEBUG   "")
 
 set(CMAKE_C_FLAGS_RELEASE          "-Os")
 set(CMAKE_CXX_FLAGS_RELEASE        "-Os")
 set(CMAKE_ASM_FLAGS_RELEASE        "")
-set(CMAKE_EXE_LINKER_FLAGS_RELEASE "")
diff --git a/examples/platforms/kw41z/CMakeLists.txt b/examples/platforms/kw41z/CMakeLists.txt
index 578661e19..3d153035e 100644
--- a/examples/platforms/kw41z/CMakeLists.txt
+++ b/examples/platforms/kw41z/CMakeLists.txt
@@ -55,7 +55,7 @@ add_library(openthread-kw41z
 set_property(TARGET openthread-kw41z PROPERTY C_STANDARD 99)
 target_link_libraries(openthread-kw41z PRIVATE nxp-kw41z-driver)
 target_link_options(openthread-kw41z PRIVATE -T${PROJECT_SOURCE_DIR}/examples/platforms/kw41z/MKW41Z512xxx4.ld)
-target_link_options(openthread-kw41z PRIVATE -Wl,-Map=$<TARGET_PROPERTY:NAME>.map)
+target_link_options(openthread-kw41z PRIVATE -Wl,--gc-sections -Wl,-Map=$<TARGET_PROPERTY:NAME>.map)
 
 target_compile_definitions(openthread-kw41z
     PUBLIC
diff --git a/examples/platforms/kw41z/arm-none-eabi.cmake b/examples/platforms/kw41z/arm-none-eabi.cmake
index f6e83f44b..d67bcb61a 100644
--- a/examples/platforms/kw41z/arm-none-eabi.cmake
+++ b/examples/platforms/kw41z/arm-none-eabi.cmake
@@ -39,14 +39,12 @@ set(COMMON_C_FLAGS                 "-mthumb -fdata-sections -ffunction-sections
 set(CMAKE_C_FLAGS                  "${COMMON_C_FLAGS} -std=gnu99")
 set(CMAKE_CXX_FLAGS                "${COMMON_C_FLAGS} -fno-exceptions -fno-rtti")
 set(CMAKE_ASM_FLAGS                "${COMMON_C_FLAGS}")
-set(CMAKE_EXE_LINKER_FLAGS         "${COMMON_C_FLAGS} -Wl,--gc-sections -specs=nano.specs -specs=nosys.specs")
+set(CMAKE_EXE_LINKER_FLAGS_INIT    "${COMMON_C_FLAGS} -specs=nano.specs -specs=nosys.specs")
 
 set(CMAKE_C_FLAGS_DEBUG            "-Og -g")
 set(CMAKE_CXX_FLAGS_DEBUG          "-Og -g")
 set(CMAKE_ASM_FLAGS_DEBUG          "-g")
-set(CMAKE_EXE_LINKER_FLAGS_DEBUG   "")
 
 set(CMAKE_C_FLAGS_RELEASE          "-Os")
 set(CMAKE_CXX_FLAGS_RELEASE        "-Os")
 set(CMAKE_ASM_FLAGS_RELEASE        "")
-set(CMAKE_EXE_LINKER_FLAGS_RELEASE "")
diff --git a/examples/platforms/qpg6095/CMakeLists.txt b/examples/platforms/qpg6095/CMakeLists.txt
index f197f3d5e..a9e6126b3 100644
--- a/examples/platforms/qpg6095/CMakeLists.txt
+++ b/examples/platforms/qpg6095/CMakeLists.txt
@@ -78,6 +78,7 @@ target_link_libraries(openthread-qpg6095
 target_link_options(openthread-qpg6095
     PUBLIC
         -T${CMAKE_CURRENT_SOURCE_DIR}/qpg6095.ld
+        -Wl,--gc-sections
         -Wl,-Map=$<TARGET_PROPERTY:NAME>.map
 )
 
diff --git a/examples/platforms/qpg6095/arm-none-eabi.cmake b/examples/platforms/qpg6095/arm-none-eabi.cmake
index ee8787e51..227520aca 100644
--- a/examples/platforms/qpg6095/arm-none-eabi.cmake
+++ b/examples/platforms/qpg6095/arm-none-eabi.cmake
@@ -39,14 +39,12 @@ set(COMMON_C_FLAGS                 "-mcpu=cortex-m4 -mthumb -fdata-sections -ffu
 set(CMAKE_C_FLAGS                  "${COMMON_C_FLAGS} -std=gnu99")
 set(CMAKE_CXX_FLAGS                "${COMMON_C_FLAGS} -fno-exceptions -fno-rtti")
 set(CMAKE_ASM_FLAGS                "${COMMON_C_FLAGS}")
-set(CMAKE_EXE_LINKER_FLAGS         "${COMMON_C_FLAGS} -specs=nano.specs -specs=nosys.specs -Wl,--gc-sections")
+set(CMAKE_EXE_LINKER_FLAGS_INIT    "${COMMON_C_FLAGS} -specs=nano.specs -specs=nosys.specs")
 
 set(CMAKE_C_FLAGS_DEBUG            "-Og -g")
 set(CMAKE_CXX_FLAGS_DEBUG          "-Og -g")
 set(CMAKE_ASM_FLAGS_DEBUG          "-g")
-set(CMAKE_EXE_LINKER_FLAGS_DEBUG   "")
 
 set(CMAKE_C_FLAGS_RELEASE          "-Os")
 set(CMAKE_CXX_FLAGS_RELEASE        "-Os")
 set(CMAKE_ASM_FLAGS_RELEASE        "")
-set(CMAKE_EXE_LINKER_FLAGS_RELEASE "")
diff --git a/examples/platforms/samr21/CMakeLists.txt b/examples/platforms/samr21/CMakeLists.txt
index c3ba4531d..38f92df86 100644
--- a/examples/platforms/samr21/CMakeLists.txt
+++ b/examples/platforms/samr21/CMakeLists.txt
@@ -75,6 +75,7 @@ target_link_libraries(openthread-samr21
 
 target_link_options(openthread-samr21
     PUBLIC
+        -Wl,--gc-sections
         -Wl,-Map=$<TARGET_PROPERTY:NAME>.map
 )
 
diff --git a/examples/platforms/samr21/arm-none-eabi.cmake b/examples/platforms/samr21/arm-none-eabi.cmake
index bf25f83f4..ff983a5ed 100644
--- a/examples/platforms/samr21/arm-none-eabi.cmake
+++ b/examples/platforms/samr21/arm-none-eabi.cmake
@@ -39,14 +39,12 @@ set(COMMON_C_FLAGS                 "-mcpu=cortex-m0plus -mfloat-abi=soft -mthumb
 set(CMAKE_C_FLAGS                  "${COMMON_C_FLAGS} -std=gnu99")
 set(CMAKE_CXX_FLAGS                "${COMMON_C_FLAGS} -fno-exceptions -fno-rtti")
 set(CMAKE_ASM_FLAGS                "${COMMON_C_FLAGS}")
-set(CMAKE_EXE_LINKER_FLAGS         "${COMMON_C_FLAGS} -specs=nano.specs -specs=nosys.specs -Wl,--gc-sections -Wl,--entry=Reset_Handler")
+set(CMAKE_EXE_LINKER_FLAGS_INIT    "${COMMON_C_FLAGS} -specs=nano.specs -specs=nosys.specs -Wl,--entry=Reset_Handler")
 
 set(CMAKE_C_FLAGS_DEBUG            "-Og -g")
 set(CMAKE_CXX_FLAGS_DEBUG          "-Og -g")
 set(CMAKE_ASM_FLAGS_DEBUG          "-g")
-set(CMAKE_EXE_LINKER_FLAGS_DEBUG   "")
 
 set(CMAKE_C_FLAGS_RELEASE          "-Os")
 set(CMAKE_CXX_FLAGS_RELEASE        "-Os")
 set(CMAKE_ASM_FLAGS_RELEASE        "")
-set(CMAKE_EXE_LINKER_FLAGS_RELEASE "")