Use LLVM LDD with clang

mattia-moffa · mattia-moffa · commit 5d61bce135d6 · 2026-04-03T17:40:00.000+02:00
diff --git a/Makefile b/Makefile
@@ -42,6 +42,10 @@ OBJS:= \
 	./src/libwolfboot.o \
 	./hal/hal.o
 
+ifeq ($(USE_CLANG),1)
+OBJS+=./src/clang_sections.o
+endif
+
 ifeq ($(WOLFCRYPT_TZ_PSA),1)
 OBJS+=./src/dice/dice.o
 endif
diff --git a/arch.mk b/arch.mk
@@ -1288,9 +1288,7 @@ ifeq ($(USE_CLANG),1)
   CLANG_NEWLIB_INCLUDE?=$(abspath $(dir $(CLANG_LIBC_A))/../include)
 
   CC=$(CLANG_DRIVER)
-  # Keep clang for compilation, but use the GNU linker driver so linker-script
-  # LMAs for RAM sections are preserved and objcopy does not emit sparse images.
-  LD=$(CLANG_GCC_NAME)
+  LD=$(CLANG_DRIVER) -fuse-ld=lld
   AS=$(CLANG_DRIVER)
   AR=$(CROSS_COMPILE)ar
   OBJCOPY?=$(CROSS_COMPILE)objcopy
@@ -1300,7 +1298,7 @@ ifeq ($(USE_CLANG),1)
   CFLAGS+=-DWOLFSSL_NO_ATOMIC -DWOLFSSL_NO_ATOMICS
   CFLAGS+=-Wno-unknown-attributes -Wno-error=unknown-attributes
   CFLAGS+=-fno-unwind-tables -fno-asynchronous-unwind-tables
-  LSCRIPT_FLAGS+=-T $(abspath $(WOLFBOOT_ROOT)/hal/clang-discard.ld)
+  LDFLAGS+=-nostdlib
 endif
 
 ifeq ($(USE_GCC),1)
diff --git a/hal/clang-discard.ld b/hal/clang-discard.ld
diff --git a/hal/lpc55s69.ld b/hal/lpc55s69.ld
@@ -30,7 +30,7 @@ SECTIONS
         *(.ARM.exidx*)
     } > FLASH
 
-    .gnu.sgstubs :
+    .gnu.sgstubs ORIGIN(FLASH_NSC) :
     {
         . += 0x400;
         . = ALIGN(4);
diff --git a/hal/mcxn.ld b/hal/mcxn.ld
@@ -30,7 +30,7 @@ SECTIONS
         *(.ARM.exidx*)
     } > FLASH
 
-    .gnu.sgstubs :
+    .gnu.sgstubs ORIGIN(FLASH_NSC) :
     {
         . += 0x400;
         . = ALIGN(4);
diff --git a/hal/mcxw.ld b/hal/mcxw.ld
@@ -30,7 +30,7 @@ SECTIONS
         *(.ARM.exidx*)
     } > FLASH
 
-    .gnu.sgstubs :
+    .gnu.sgstubs ORIGIN(FLASH_NSC) :
     {
         . += 0x400;
         . = ALIGN(4);
diff --git a/hal/nrf5340.ld b/hal/nrf5340.ld
@@ -29,7 +29,7 @@ SECTIONS
         *(.ARM.exidx*)
     } > FLASH
 
-    .gnu.sgstubs :
+    .gnu.sgstubs ORIGIN(FLASH_NSC) :
     {
         . += 0x400;
         . = ALIGN(4);
diff --git a/hal/nrf54l.ld b/hal/nrf54l.ld
@@ -29,7 +29,7 @@ SECTIONS
         *(.ARM.exidx*)
     } > FLASH
 
-    .gnu.sgstubs :
+    .gnu.sgstubs ORIGIN(FLASH_NSC) :
     {
         . += 0x400;
         . = ALIGN(4);
diff --git a/hal/rp2350.ld b/hal/rp2350.ld
@@ -102,7 +102,7 @@ SECTIONS
         . = ALIGN(4);
     } > FLASH
 
-    .gnu.sgstubs :
+    .gnu.sgstubs ORIGIN(FLASH_NSC) :
     {
         *(.gnu.sgstubs*)   /* Secure Gateway stubs */
         . = ALIGN(4);
diff --git a/hal/stm32h5.ld b/hal/stm32h5.ld
@@ -25,7 +25,7 @@ SECTIONS
         *(.ARM.exidx*)
     } > FLASH
 
-    .gnu.sgstubs :
+    .gnu.sgstubs ORIGIN(FLASH_NSC) :
     {
         . = ALIGN(32);
         *(.gnu.sgstubs*)   /* Secure Gateway stubs */
diff --git a/hal/stm32l5.ld b/hal/stm32l5.ld
@@ -25,7 +25,7 @@ SECTIONS
         *(.ARM.exidx*)
     } > FLASH
 
-    .gnu.sgstubs :
+    .gnu.sgstubs ORIGIN(FLASH_NSC) :
     {
         . += 0x400;
         . = ALIGN(4);
diff --git a/hal/stm32u5.ld b/hal/stm32u5.ld
@@ -25,7 +25,7 @@ SECTIONS
         *(.ARM.exidx*)
     } > FLASH
 
-    .gnu.sgstubs :
+    .gnu.sgstubs ORIGIN(FLASH_NSC) :
     {
         . += 0x400;
         . = ALIGN(4);
diff --git a/src/clang_sections.S b/src/clang_sections.S
diff --git a/test-app/Makefile b/test-app/Makefile
@@ -102,10 +102,9 @@ LDFLAGS+=-T $(LSCRIPT) -Wl,-gc-sections -Wl,-Map=image.map -nostartfiles
 
 # Setup default objcopy flags
 OBJCOPY_FLAGS+=--gap-fill $(FILL_BYTE)
-OBJCOPY_IMAGE_FLAGS?=
 
 ifeq ($(USE_CLANG),1)
-  APP_OBJS+=clang_sections.o
+  APP_OBJS+=../src/clang_sections.o
 endif
 
 ifeq ($(DEBUG_UART),1)
@@ -925,15 +924,15 @@ delta-extra-data:LDFLAGS=-Wl,-Map=image.map
 
 image.bin: image.elf
 	@echo "\t[BIN] $@"
-	$(Q)$(OBJCOPY) $(OBJCOPY_FLAGS) $(OBJCOPY_IMAGE_FLAGS) -O binary $^ $@
+	$(Q)$(OBJCOPY) $(OBJCOPY_FLAGS) -O binary $^ $@
 
 image.hex: image.elf
 	@echo "\t[HEX] $@"
-	$(Q)$(OBJCOPY) $(OBJCOPY_FLAGS) $(OBJCOPY_IMAGE_FLAGS) -O ihex $^ $@
+	$(Q)$(OBJCOPY) $(OBJCOPY_FLAGS) -O ihex $^ $@
 
 image.srec: image.elf
 	@echo "\t[SREC] $@"
-	$(Q)$(OBJCOPY) $(OBJCOPY_FLAGS) $(OBJCOPY_IMAGE_FLAGS) -O srec $^ $@
+	$(Q)$(OBJCOPY) $(OBJCOPY_FLAGS) -O srec $^ $@
 
 APP_OBJS := $(patsubst $(WOLFBOOT_LIB_WOLFSSL)/%, \
     $(WOLFSSL_LOCAL_OBJDIR)/%, $(APP_OBJS))
@@ -943,7 +942,7 @@ ifeq ($(ELF_FLASH_SCATTER),1)
 SQUASHELF_TOOL = ../tools/squashelf/squashelf
 image-orig.elf: $(APP_OBJS) $(LSCRIPT)
 	@echo "\t[LD] $@"
-	$(Q)$(LD) $(LDFLAGS) $(LSCRIPT_FLAGS) $(APP_OBJS) $(LIBS) $(OUTPUT_FLAG) $@
+	$(Q)$(LD) $(LDFLAGS) $(APP_OBJS) $(LIBS) $(OUTPUT_FLAG) $@
 
 image.elf: image-orig.elf
 	@echo "\t[SQUASHELF] $@"
@@ -952,7 +951,7 @@ else
 # Default behavior when ELF_FLASH_SCATTER is not set
 image.elf: $(APP_OBJS) $(LSCRIPT)
 	@echo "\t[LD] $@"
-	$(Q)$(LD) $(LDFLAGS) $(LSCRIPT_FLAGS) $(APP_OBJS) $(LIBS) $(OUTPUT_FLAG) $@
+	$(Q)$(LD) $(LDFLAGS) $(APP_OBJS) $(LIBS) $(OUTPUT_FLAG) $@
 endif
 
 standalone: image.bin

Original file line number	Diff line number	Diff line change
`@@ -30,7 +30,7 @@ SECTIONS`
`30`	`30`	`(.ARM.exidx)`
`31`	`31`	`} > FLASH`
`32`	`32`
`33`		`- .gnu.sgstubs :`
	`33`	`+ .gnu.sgstubs ORIGIN(FLASH_NSC) :`
`34`	`34`	`{`
`35`	`35`	`. += 0x400;`
`36`	`36`	`. = ALIGN(4);`
Original file line number	Diff line number	Diff line change
`@@ -29,7 +29,7 @@ SECTIONS`
`29`	`29`	`(.ARM.exidx)`
`30`	`30`	`} > FLASH`
`31`	`31`
`32`		`- .gnu.sgstubs :`
	`32`	`+ .gnu.sgstubs ORIGIN(FLASH_NSC) :`
`33`	`33`	`{`
`34`	`34`	`. += 0x400;`
`35`	`35`	`. = ALIGN(4);`
Original file line number	Diff line number	Diff line change
`@@ -102,7 +102,7 @@ SECTIONS`
`102`	`102`	`. = ALIGN(4);`
`103`	`103`	`} > FLASH`
`104`	`104`
`105`		`- .gnu.sgstubs :`
	`105`	`+ .gnu.sgstubs ORIGIN(FLASH_NSC) :`
`106`	`106`	`{`
`107`	`107`	`(.gnu.sgstubs) /* Secure Gateway stubs */`
`108`	`108`	`. = ALIGN(4);`
Original file line number	Diff line number	Diff line change
`@@ -25,7 +25,7 @@ SECTIONS`
`25`	`25`	`(.ARM.exidx)`
`26`	`26`	`} > FLASH`
`27`	`27`
`28`		`- .gnu.sgstubs :`
	`28`	`+ .gnu.sgstubs ORIGIN(FLASH_NSC) :`
`29`	`29`	`{`
`30`	`30`	`. = ALIGN(32);`
`31`	`31`	`(.gnu.sgstubs) /* Secure Gateway stubs */`