stm32/stm32.mk: Error out if compiling for cortex-m55 on old gcc.

dpgeorge · dpgeorge · commit 99740dbace96 · 2025-07-08T16:28:58.000+10:00
Signed-off-by: Damien George &lt;damien@micropython.org&gt;
diff --git a/ports/stm32/Makefile b/ports/stm32/Makefile
@@ -60,6 +60,7 @@ include $(TOP)/extmod/extmod.mk
 
 GIT_SUBMODULES += lib/libhydrogen lib/stm32lib
 
+CROSS_COMPILE ?= arm-none-eabi-
 LD_DIR=boards
 USBDEV_DIR=usbdev
 #USBHOST_DIR=usbhost
@@ -101,9 +102,6 @@ GEN_STMCONST_HDR = $(HEADER_BUILD)/modstm_const.h
 GEN_STMCONST_MPZ = $(HEADER_BUILD)/modstm_mpz.h
 CMSIS_MCU_HDR = $(STM32LIB_CMSIS_ABS)/Include/$(CMSIS_MCU_LOWER).h
 
-# Select the cross compile prefix
-CROSS_COMPILE ?= arm-none-eabi-
-
 INC += -I.
 INC += -I$(TOP)
 INC += -I$(BUILD)
diff --git a/ports/stm32/mboot/Makefile b/ports/stm32/mboot/Makefile
@@ -48,6 +48,7 @@ endif
 MBOOT_VERSION_ALLOCATED_BYTES ?= 64
 MBOOT_VERSION_INCLUDE_OPTIONS ?= 1  # if set to 1, this will append build options to version string (see version.c)
 
+CROSS_COMPILE ?= arm-none-eabi-
 USBDEV_DIR=usbdev
 DFU=$(TOP)/tools/dfu.py
 PYDFU ?= $(TOP)/tools/pydfu.py
@@ -59,8 +60,6 @@ OPENOCD_CONFIG ?= boards/openocd_stm32f4.cfg
 
 include ../stm32.mk
 
-CROSS_COMPILE ?= arm-none-eabi-
-
 INC += -I.
 INC += -I..
 INC += -I$(TOP)
diff --git a/ports/stm32/stm32.mk b/ports/stm32/stm32.mk
@@ -83,3 +83,17 @@ MPY_CROSS_MCU_ARCH_h7 = armv7m
 MPY_CROSS_MCU_ARCH_n6 = armv7m # really armv8m
 MPY_CROSS_MCU_ARCH_wb = armv7m
 MPY_CROSS_MCU_ARCH_wl = armv7m
+
+# gcc up to 14.2.0 have a known loop-optimisation bug:
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116799
+# This bug manifests for Cortex M55 targets, so require a newer compiler on such targets.
+ifeq ($(MCU_SERIES),n6)
+# Check if GCC version is less than 14.3
+GCC_VERSION := $(shell $(CROSS_COMPILE)gcc -dumpversion | cut -d. -f1-2)
+GCC_VERSION_MAJOR := $(shell echo $(GCC_VERSION) | cut -d. -f1)
+GCC_VERSION_MINOR := $(shell echo $(GCC_VERSION) | cut -d. -f2)
+GCC_VERSION_NUM := $(shell echo $$(($(GCC_VERSION_MAJOR) * 100 + $(GCC_VERSION_MINOR))))
+ifeq ($(shell test $(GCC_VERSION_NUM) -lt 1403 && echo yes),yes)
+$(error Error: GCC $(GCC_VERSION) has known issues with Cortex-M55; upgrade to GCC 14.3+ for proper CM55 support)
+endif
+endif
