With binutils >= 2.38 the default risc-v ISA spec version has been bumped to 20191213, so we now need to specify the extension for csr and fence.i as well. Do it the kernel way and port commit | commit 6df2a016c0c8a3d0933ef33dd192ea6606b115e3 | Author: Aurelien Jarno <aurelien@xxxxxxxxxxx> | Date: Wed Jan 26 18:14:42 2022 +0100 | | riscv: fix build with binutils 2.38 | | 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. | | Signed-off-by: Aurelien Jarno <aurelien@xxxxxxxxxxx> | Tested-by: Alexandre Ghiti <alexandre.ghiti@xxxxxxxxxxxxx> | Cc: stable@xxxxxxxxxxxxxxx | Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx> Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx> --- arch/riscv/Makefile | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index d1b689b493..1371f17e7c 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -16,6 +16,10 @@ endif riscv-march-$(CONFIG_ARCH_RV32I) := rv32im riscv-march-$(CONFIG_ARCH_RV64I) := rv64im +# 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) := $(riscv-march-y)_zicsr_zifencei KBUILD_CPPFLAGS += -march=$(riscv-march-y) KBUILD_CPPFLAGS += -Wstrict-prototypes -mcmodel=medany -fpic -- 2.39.1
