linker: Introduce linker-tool-lld.h

cmake/linker/lld/target_base.cmake

@@ -5,7 +5,7 @@
 macro(toolchain_ld_base)
 
   if(NOT PROPERTY_LINKER_SCRIPT_DEFINES)
-    set_property(GLOBAL PROPERTY PROPERTY_LINKER_SCRIPT_DEFINES -D__GCC_LINKER_CMD__)
+    set_property(GLOBAL PROPERTY PROPERTY_LINKER_SCRIPT_DEFINES -D__LLD_LINKER_CMD__)
   endif()
 
   # TOOLCHAIN_LD_FLAGS comes from compiler/clang/target.cmake

include/zephyr/linker/linker-tool-lld.h

@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2023, Google, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @file
+ * @brief LLVM LLD linker defs
+ *
+ * This header file defines the necessary macros used by the linker script for
+ * use with the LLD linker.
+ */
+
+#ifndef ZEPHYR_INCLUDE_LINKER_LINKER_TOOL_LLD_H_
+#define ZEPHYR_INCLUDE_LINKER_LINKER_TOOL_LLD_H_
+
+#include <zephyr/linker/linker-tool-gcc.h>
+
+/**
+ * @def SECTION_PROLOGUE
+ *
+ * The SECTION_PROLOGUE() macro is used to define the beginning of a section.
+ *
+ * When --omagic (-N) option is provided to LLD then only the first output
+ * section of given region has aligned LMA (by default, without --omagic, LLD
+ * aligns LMA and VMA of every section to the same value) and the difference
+ * between VMA addresses (0 is this is the first section) is added.
+ * The difference between LMA and VMA is constant for every section, so this
+ * emulates ALIGN_WITH_INPUT option present in GNU LD (required by XIP systems).
+ *
+ * The --omagic flag is defined in cmake/linker/lld/target_baremetal.cmake
+ *
+ * @param name Name of the output section
+ * @param options Section options, such as (NOLOAD), or left blank
+ * @param align Alignment directives, such as SUBALIGN(). May be blank.
+ */
+#undef SECTION_PROLOGUE
+#define SECTION_PROLOGUE(name, options, align) \
+	name options : align
+
+/**
+ * @def SECTION_DATA_PROLOGUE
+ *
+ * Same as for SECTION_PROLOGUE(), except that this one must be used
+ * for data sections which on XIP platforms will have differing
+ * virtual and load addresses (i.e. they'll be copied into RAM at
+ * program startup).  Such a section must also use
+ * GROUP_DATA_LINK_IN to specify the correct output load address.
+ *
+ * This is equivalent to SECTION_PROLOGUE() when linking using LLD.
+ *
+ * @param name Name of the output section
+ * @param options Section options, or left blank
+ * @param align Alignment directives, such as SUBALIGN(). May be blank.
+ */
+#undef SECTION_DATA_PROLOGUE
+#define SECTION_DATA_PROLOGUE(name, options, align) \
+	SECTION_PROLOGUE(name, options, align)
+
+#endif /* ZEPHYR_INCLUDE_LINKER_LINKER_TOOL_LLD_H_ */

include/zephyr/linker/linker-tool.h

@@ -20,6 +20,8 @@
 #include <zephyr/linker/linker-tool-gcc.h>
 #elif defined(__MWDT_LINKER_CMD__)
 #include <zephyr/linker/linker-tool-mwdt.h>
+#elif defined(__LLD_LINKER_CMD__)
+#include <zephyr/linker/linker-tool-lld.h>
 #else
 #error "Unknown toolchain"
 #endif

include/zephyr/toolchain.h

@@ -44,7 +44,7 @@
 #include <zephyr/toolchain/mwdt.h>
 #elif defined(__ARMCOMPILER_VERSION)
 #include <zephyr/toolchain/armclang.h>
-#elif defined(__llvm__)
+#elif defined(__llvm__) || (defined(_LINKER) && defined(__LLD_LINKER_CMD__))
 #include <zephyr/toolchain/llvm.h>
 #elif defined(__GNUC__) || (defined(_LINKER) && defined(__GCC_LINKER_CMD__))
 #include <zephyr/toolchain/gcc.h>