From 240564a6933d9300473b5ced02d2f6f2a2fa4cd9 Mon Sep 17 00:00:00 2001 From: Vicente Olivert Riera Date: Wed, 9 Nov 2016 16:16:57 +0000 Subject: [PATCH] arch/Config.in.mips: add support for XBurst cores The Ingenic XBurst is a MIPS32R2 microprocessor. It has a bug in the FPU that can generate incorrect results in certain cases. The problem shows up when you have several fused madd instructions in sequence with dependant operands. Using the -mno-fused-madd option prevents gcc from emitting these instructions. This patch adds changes to the toolchain wrapper to use that option. Signed-off-by: Vicente Olivert Riera Signed-off-by: Thomas Petazzoni --- arch/Config.in.mips | 14 ++++++++++++++ toolchain/toolchain-wrapper.c | 3 +++ toolchain/toolchain-wrapper.mk | 5 +++++ 3 files changed, 22 insertions(+) diff --git a/arch/Config.in.mips b/arch/Config.in.mips index 3662fedca8..1021a579b9 100644 --- a/arch/Config.in.mips +++ b/arch/Config.in.mips @@ -63,6 +63,19 @@ config BR2_mips_p5600 bool "P5600" depends on !BR2_ARCH_IS_64 select BR2_MIPS_CPU_MIPS32R5 +config BR2_mips_xburst + bool "XBurst" + depends on !BR2_ARCH_IS_64 + select BR2_MIPS_CPU_MIPS32R2 + help + The Ingenic XBurst is a MIPS32R2 microprocessor. It has a + bug in the FPU that can generate incorrect results in + certain cases. The problem shows up when you have several + fused madd instructions in sequence with dependant + operands. This requires the -mno-fused-madd compiler option + to be used in order to prevent emitting these instructions. + + See http://www.ingenic.com/en/?xburst.html config BR2_mips_64 bool "Generic MIPS64" depends on BR2_ARCH_IS_64 @@ -137,6 +150,7 @@ config BR2_GCC_TARGET_ARCH default "m5101" if BR2_mips_m5101 default "m6201" if BR2_mips_m6201 default "p5600" if BR2_mips_p5600 + default "mips32r2" if BR2_mips_xburst default "mips64" if BR2_mips_64 default "mips64r2" if BR2_mips_64r2 default "mips64r5" if BR2_mips_64r5 diff --git a/toolchain/toolchain-wrapper.c b/toolchain/toolchain-wrapper.c index 925d01394c..d59629b048 100644 --- a/toolchain/toolchain-wrapper.c +++ b/toolchain/toolchain-wrapper.c @@ -66,6 +66,9 @@ static char *predef_args[] = { #ifdef BR_OMIT_LOCK_PREFIX "-Wa,-momit-lock-prefix=yes", #endif +#ifdef BR_NO_FUSED_MADD + "-mno-fused-madd", +#endif #ifdef BR_BINFMT_FLAT "-Wl,-elf2flt", #endif diff --git a/toolchain/toolchain-wrapper.mk b/toolchain/toolchain-wrapper.mk index e7aa5fb829..c7b50195d3 100644 --- a/toolchain/toolchain-wrapper.mk +++ b/toolchain/toolchain-wrapper.mk @@ -26,6 +26,11 @@ ifeq ($(BR2_x86_x1000),y) TOOLCHAIN_WRAPPER_ARGS += -DBR_OMIT_LOCK_PREFIX endif +# Avoid FPU bug on XBurst CPUs +ifeq ($(BR2_mips_xburst),y) +TOOLCHAIN_WRAPPER_ARGS += -DBR_NO_FUSED_MADD +endif + ifeq ($(BR2_CCACHE_USE_BASEDIR),y) TOOLCHAIN_WRAPPER_ARGS += -DBR_CCACHE_BASEDIR='"$(BASE_DIR)"' endif -- 2.30.2