Found in http://www.spinics.net/lists/linux-sh/msg51060.html, a Buildroot generated toolchain for SH4 fails to build the Linux kernel magicpanelr2_defconfig: /opt/cross/kisskb/br-sh4-full-2016.08-613-ge98b4dd/bin/sh4-linux-ld: kernel/sched/built-in.o: uses dsp instructions while previous modules use floating point instructions /opt/cross/kisskb/br-sh4-full-2016.08-613-ge98b4dd/bin/sh4-linux-ld: kernel/sched/built-in.o: uses instructions which are incompatible with instructions used in previous modules /opt/cross/kisskb/br-sh4-full-2016.08-613-ge98b4dd/bin/sh4-linux-ld: failed to merge target specific data of file kernel/sched/built-in.o /home/kisskb/slave/src/scripts/Makefile.build:380: recipe for target 'kernel/built-in.o' failed make[2]: *** [kernel/built-in.o] Error 1 Full build log at http://kisskb.ellerman.id.au/kisskb/buildresult/12857629/log/ (Note: this is a bug from January 2017, which I notice only now. Before I forget, I fill in a bug report about it, so we can have a look at it later.)
This problem can be reproduced with the following defconfig: BR2_sh=y BR2_LINUX_KERNEL=y BR2_LINUX_KERNEL_DEFCONFIG="magicpanelr2" BR2_LINUX_KERNEL_NEEDS_HOST_OPENSSL=y
Reproduced on the current buildroot git head. From linux commit ded5431ff311d963888ac951131a04fe7633aa79: """ From ded5431ff311d963888ac951131a04fe7633aa79 Mon Sep 17 00:00:00 2001 From: Markus Brunner <super.firetwister@gmail.com> Date: Wed, 12 Sep 2007 11:54:58 +0900 Subject: sh: Magic Panel R2 board support. This adds support for the SH7720 (SH3-DSP) based Magic Panel R2 board. """ The Magic Panel R2 is a SH3 board, not a SH4 board, it's not supported by buildroot. The root cause is that the SH3-DSP scheduler code saves and loads the SH3 DSP registers via inline ASM, and mixing SH3-DSP code with SH4-FPU code isn't supported. Marking as RESOLVED/WONTFIX