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-rw-r--r--arch/riscv/Kconfig22
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index c5e42cc37604..5b182d1c196c 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -464,6 +464,28 @@ config TOOLCHAIN_HAS_ZIHINTPAUSE
depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zihintpause)
depends on LLD_VERSION >= 150000 || LD_VERSION >= 23600
+config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
+ def_bool y
+ # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc
+ depends on AS_IS_GNU && AS_VERSION >= 23800
+ help
+ Newer binutils versions default to ISA spec version 20191213 which
+ moves some instructions from the I extension to the Zicsr and Zifencei
+ extensions.
+
+config TOOLCHAIN_NEEDS_OLD_ISA_SPEC
+ def_bool y
+ depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
+ # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16
+ depends on CC_IS_CLANG && CLANG_VERSION < 170000
+ help
+ Certain versions of clang do not support zicsr and zifencei via -march
+ but newer versions of binutils require it for the reasons noted in the
+ help text of CONFIG_TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI. This
+ option causes an older ISA spec compatible with these older versions
+ of clang to be passed to GAS, which has the same result as passing zicsr
+ and zifencei to -march.
+
config FPU
bool "FPU support"
default y