Hi Aurelien, On Wed, Jan 26, 2022 at 6:41 PM Aurelien Jarno <aurelien@xxxxxxxxxxx> wrote: > > From version 2.38, binutils default to ISA spec version 20191213. This > means that the csr read/write (csrr*/csrw*) instructions and fence.i > instruction has separated from the `I` extension, become two standalone > extensions: Zicsr and Zifencei. As the kernel uses those instruction, > this causes the following build failure: > > CC arch/riscv/kernel/vdso/vgettimeofday.o > <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h: Assembler messages: > <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01' > <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01' > <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01' > <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01' > > The fix is to specify those extensions explicitely in -march. However as > older binutils version do not support this, we first need to detect > that. > > Cc: stable@xxxxxxxxxxxxxxx # 4.15+ > Cc: Kito Cheng <kito.cheng@xxxxxxxxx> > Signed-off-by: Aurelien Jarno <aurelien@xxxxxxxxxxx> > --- > arch/riscv/Makefile | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile > index 8a107ed18b0d..7d81102cffd4 100644 > --- a/arch/riscv/Makefile > +++ b/arch/riscv/Makefile > @@ -50,6 +50,12 @@ riscv-march-$(CONFIG_ARCH_RV32I) := rv32ima > riscv-march-$(CONFIG_ARCH_RV64I) := rv64ima > riscv-march-$(CONFIG_FPU) := $(riscv-march-y)fd > riscv-march-$(CONFIG_RISCV_ISA_C) := $(riscv-march-y)c > + > +# Newer binutils versions default to ISA spec version 20191213 which moves some > +# instructions from the I extension to the Zicsr and Zifencei extensions. > +toolchain-need-zicsr-zifencei := $(call cc-option-yn, -march=$(riscv-march-y)_zicsr_zifencei) > +riscv-march-$(toolchain-need-zicsr-zifencei) := $(riscv-march-y)_zicsr_zifencei > + > KBUILD_CFLAGS += -march=$(subst fd,,$(riscv-march-y)) > KBUILD_AFLAGS += -march=$(riscv-march-y) > > -- > 2.34.1 > > That fixes our kernel build with the new binutils, so you can add: Tested-by: Alexandre Ghiti <alexandre.ghiti@xxxxxxxxxxxxx> Thanks for working on this! Alex > _______________________________________________ > linux-riscv mailing list > linux-riscv@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-riscv
