LLD fixes, warning and handling

CMakeLists.txt

@@ -1714,13 +1714,8 @@ if(CONFIG_BUILD_OUTPUT_ADJUST_LMA)
     )
 endif()
 
-if(NOT CONFIG_CPP_EXCEPTIONS)
-  set(eh_frame_section ".eh_frame")
-else()
-  set(eh_frame_section "")
-endif()
 set(remove_sections_argument_list "")
-foreach(section .comment COMMON ${eh_frame_section})
+foreach(section .comment COMMON)
   list(APPEND remove_sections_argument_list
     $<TARGET_PROPERTY:bintools,elfconvert_flag_section_remove>${section})
 endforeach()

include/zephyr/arch/arm/cortex_a_r/scripts/linker.ld

@@ -402,11 +402,9 @@ GROUP_END(OCM)
     /* Must be last in romable region */
     SECTION_PROLOGUE(.last_section,,)
     {
-#ifdef CONFIG_LINKER_LAST_SECTION_ID
-      /* Fill last section with a word to ensure location counter and actual rom
-       * region data usage match. */
-      LONG(CONFIG_LINKER_LAST_SECTION_ID_PATTERN)
-#endif
+      /* .last_section contains a fixed word to ensure location counter and actual
+       * rom region data usage match when CONFIG_LINKER_LAST_SECTION_ID=y. */
+      KEEP(*(.last_section))
     } GROUP_LINK_IN(ROMABLE_REGION)
 
     /* To provide the image size as a const expression,

include/zephyr/arch/arm/cortex_m/scripts/linker.ld

@@ -488,11 +488,9 @@ GROUP_END(DTCM)
 /* Must be last in romable region */
 SECTION_PROLOGUE(.last_section,,)
 {
-#ifdef CONFIG_LINKER_LAST_SECTION_ID
-  /* Fill last section with a word to ensure location counter and actual rom
-   * region data usage match. */
-  LONG(CONFIG_LINKER_LAST_SECTION_ID_PATTERN)
-#endif
+  /* .last_section contains a fixed word to ensure location counter and actual
+   * rom region data usage match when CONFIG_LINKER_LAST_SECTION_ID=y. */
+  KEEP(*(.last_section))
 } GROUP_LINK_IN(ROMABLE_REGION)
 
 /* To provide the image size as a const expression,

include/zephyr/arch/arm64/scripts/linker.ld

@@ -351,11 +351,9 @@ SECTIONS
     /* Must be last in romable region */
     SECTION_PROLOGUE(.last_section,,)
     {
-#ifdef CONFIG_LINKER_LAST_SECTION_ID
-      /* Fill last section with a word to ensure location counter and actual rom
-       * region data usage match. */
-      LONG(CONFIG_LINKER_LAST_SECTION_ID_PATTERN)
-#endif
+      /* .last_section contains a fixed word to ensure location counter and actual
+       * rom region data usage match when CONFIG_LINKER_LAST_SECTION_ID=y. */
+      KEEP(*(.last_section))
     } GROUP_ROM_LINK_IN(RAMABLE_REGION, ROMABLE_REGION)
 
     /* To provide the image size as a const expression,

include/zephyr/arch/riscv/common/linker.ld

@@ -454,15 +454,13 @@ GROUP_END(DTCM)
 /* Must be last in romable region */
 SECTION_PROLOGUE(.last_section,,)
 {
-#ifdef CONFIG_LINKER_LAST_SECTION_ID
-  /* Fill last section with a word to ensure location counter and actual rom
-   * region data usage match. */
-  LONG(CONFIG_LINKER_LAST_SECTION_ID_PATTERN)
+  /* .last_section contains a fixed word to ensure location counter and actual
+   * rom region data usage match when CONFIG_LINKER_LAST_SECTION_ID=y. */
+  KEEP(*(.last_section))
   /* __rom_region_size is used when configuring the PMP entry of the ROM region.
    * Addresses (pmpaddr) in PMP registers need to be aligned to 4. Align
    * __rom_region_size to 4 to meet that requirement. */
   MPU_MIN_SIZE_ALIGN
-#endif
 } GROUP_LINK_IN(ROMABLE_REGION)
 
 /* To provide the image size as a const expression,

include/zephyr/arch/x86/ia32/linker.ld

@@ -557,12 +557,6 @@ SECTIONS
 #include <zephyr/linker/debug-sections.ld>
 
 	/DISCARD/ : { *(.note.GNU-stack) }
-/*
- * eh_frame section won't be removed even with "--gc-sections" by LLVM lld.
- */
-#if !defined(CONFIG_CPP_EXCEPTIONS)
-	/DISCARD/ : { *(.eh_frame) }
-#endif
 
 /*
  * The sections below are still treated as warnings

include/zephyr/arch/x86/intel64/linker.ld

@@ -223,12 +223,6 @@ SECTIONS
 	*(.rel.*)
 	*(.rela.*)
 	}
-/*
- * eh_frame section won't be removed even with "--gc-sections" by LLVM lld.
- */
-#if !defined(CONFIG_CPP_EXCEPTIONS)
-	/DISCARD/ : { *(.eh_frame) }
-#endif
 
 /*
  * The sections below are still treated as warnings

include/zephyr/linker/cplusplus-rom.ld

@@ -24,3 +24,7 @@
 #endif /* CONFIG_CPP_EXCEPTIONS */
 
 #endif /* CONFIG_CPP */
+
+#if !defined(CONFIG_CPP_EXCEPTIONS)
+	/DISCARD/ : { *(.eh_frame) }
+#endif

lib/utils/CMakeLists.txt

@@ -25,3 +25,5 @@ zephyr_library_include_directories(
   ${ZEPHYR_BASE}/kernel/include
   ${ZEPHYR_BASE}/arch/${ARCH}/include
 )
+
+zephyr_sources_ifdef(CONFIG_LINKER_LAST_SECTION_ID last_section_id.c)

lib/utils/last_section_id.c

@@ -0,0 +1,10 @@
+/*
+ * Copyright (C) 2025, Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ */
+#include <zephyr/types.h>
+
+static uint32_t last_id __attribute__((section(".last_section"))) __attribute__((__used__)) =
+	CONFIG_LINKER_LAST_SECTION_ID_PATTERN;

soc/andestech/ae350/linker.ld

@@ -412,11 +412,9 @@ GROUP_END(DTCM)
 /* Must be last in romable region */
 SECTION_PROLOGUE(.last_section,,)
 {
-#ifdef CONFIG_LINKER_LAST_SECTION_ID
-  /* Fill last section with a word to ensure location counter and actual rom
-   * region data usage match. */
-  LONG(CONFIG_LINKER_LAST_SECTION_ID_PATTERN)
-#endif
+  /* .last_section contains a fixed word to ensure location counter and actual
+   * rom region data usage match when CONFIG_LINKER_LAST_SECTION_ID=y. */
+  KEEP(*(.last_section))
 } GROUP_LINK_IN(ROMABLE_REGION)
 
 /* Because ROMABLE_REGION != RAMABLE_REGION in XIP-system, it is valid

soc/infineon/cat1b/cyw20829/linker.ld

@@ -466,11 +466,9 @@ GROUP_END(DTCM)
 /* Must be last in romable region */
 SECTION_PROLOGUE(.last_section,,)
 {
-#ifdef CONFIG_LINKER_LAST_SECTION_ID
-  /* Fill last section with a word to ensure location counter and actual rom
-   * region data usage match. */
-  LONG(CONFIG_LINKER_LAST_SECTION_ID_PATTERN)
-#endif
+  /* .last_section contains a fixed word to ensure location counter and actual
+   * rom region data usage match when CONFIG_LINKER_LAST_SECTION_ID=y. */
+  KEEP(*(.last_section))
 } GROUP_LINK_IN(ROMABLE_REGION)
 
 /* To provide the image size as a const expression,