From f1217c803cec90813eb834dde7829f4961b2a2e4 Mon Sep 17 00:00:00 2001
From: Khem Raj <raj.khem@gmail.com>
Date: Thu, 17 Feb 2022 15:07:02 -0800
Subject: [PATCH] configure.ac: Use _zicsr_zifencei extentions on riscv

From version 2.38, binutils defaults 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.

The fix is to specify those extensions explicitely in -march. Since we
are now using binutils 2.38+ in OE this is ok, a more upstreamable fix for
grub will be to detect these extentions, however thats not easy to
implement

Upstream-Status: Inappropriate [OE specific]
Signed-off-by: Khem Raj <raj.khem@gmail.com>
---
 configure.ac | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/configure.ac b/configure.ac
index c7fc55a..072f2c9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -849,14 +849,14 @@ if test x"$platform" != xemu ; then
 		         [grub_cv_target_cc_soft_float="-mgeneral-regs-only"], [])
     fi
     if test "x$target_cpu" = xriscv32; then
-       CFLAGS="$TARGET_CFLAGS -march=rv32imac -mabi=ilp32 -Werror"
+       CFLAGS="$TARGET_CFLAGS -march=rv32imac_zicsr_zifencei -mabi=ilp32 -Werror"
        AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[]])],
-		         [grub_cv_target_cc_soft_float="-march=rv32imac -mabi=ilp32"], [])
+		         [grub_cv_target_cc_soft_float="-march=rv32imac_zicsr_zifencei -mabi=ilp32"], [])
     fi
     if test "x$target_cpu" = xriscv64; then
-       CFLAGS="$TARGET_CFLAGS -march=rv64imac -mabi=lp64 -Werror"
+       CFLAGS="$TARGET_CFLAGS -march=rv64imac_zicsr_zifencei -mabi=lp64 -Werror"
        AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[]])],
-		         [grub_cv_target_cc_soft_float="-march=rv64imac -mabi=lp64"], [])
+		         [grub_cv_target_cc_soft_float="-march=rv64imac_zicsr_zifencei -mabi=lp64"], [])
     fi
     if test "x$target_cpu" = xia64; then
        CFLAGS="$TARGET_CFLAGS -mno-inline-float-divide -mno-inline-sqrt -Werror"
-- 
2.35.1