From 5448f328ff63a6ca4a64519c2f1dfc63a33df4b7 Mon Sep 17 00:00:00 2001 From: Thomas Petazzoni Date: Thu, 10 Sep 2020 11:37:33 +0200 Subject: [PATCH] Pass -fno-builtin to fix build with gcc 10 gcc 10, if it recognizes some hand-written code that looks like memcpy, will generate a call to memcpy(). For example: while (dst < &_end_data) { *dst++ = *src++; } gets recognized as such. However, in the context of bare-metal code, having a call to memcpy() in the C library doesn't work. So we fix that by disabling builtins. Fixes: /home/thomas/projets/buildroot/output/host/opt/ext-toolchain/bin/../arm-buildroot-uclinux-uclibcgnueabi/bin/ld.real: stm32f429i-disco.o: in function `reset': stm32f429i-disco.c:(.text.reset+0x1a): undefined reference to `memcpy' /home/thomas/projets/buildroot/output/host/opt/ext-toolchain/bin/../arm-buildroot-uclinux-uclibcgnueabi/bin/ld.real: stm32f429i-disco.c:(.text.reset+0x34): undefined reference to `memset' make[1]: *** [Makefile:26: stm32f429i-disco] Error 1 Upstream: https://github.com/mcoquelin-stm32/afboot-stm32/pull/9 Signed-off-by: Thomas Petazzoni --- Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/Makefile b/Makefile index f699176..1e8557d 100644 --- a/Makefile +++ b/Makefile @@ -13,6 +13,7 @@ DTB_ADDR?=0x08004000 CFLAGS := -mthumb -mcpu=cortex-m4 CFLAGS += -ffunction-sections -fdata-sections CFLAGS += -Os -std=gnu99 -Wall +CFLAGS += -fno-builtin LINKERFLAGS := -nostartfiles --gc-sections obj-y += gpio.o mpu.o qspi.o start_kernel.o -- 2.26.2