qemu/Makefile-fix-build-with-binutils-2.38.patch

From: Aurelien Jarno <aurelien@aurel32.net>
Date: Fri, 28 Jan 2022 18:33:46 +0100
Subject: Makefile: fix build with binutils 2.38

Git-commit: 5d53b55aa77ffeefd4012445dfa6ad3535e1ff2c

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        lib/sbi/sbi_tlb.o
<<BUILDDIR>>/lib/sbi/sbi_tlb.c: Assembler messages:
<<BUILDDIR>>/lib/sbi/sbi_tlb.c:190: Error: unrecognized opcode `fence.i'
make: *** [Makefile:431: <<BUILDDIR>>/build/lib/sbi/sbi_tlb.o] Error 1

The fix is to specify those extensions explicitly in -march. However as
older binutils version do not support this, we first need to detect
that.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Dario Faggioli <dfaggioli@suse.com>
---
 Makefile | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/roms/opensbi/Makefile b/roms/opensbi/Makefile
index d6f097d30af78c0fba92eeeec523..a294f46fa8e16caec64d5a88c2a2 100644
--- a/roms/opensbi/Makefile
+++ b/roms/opensbi/Makefile
@@ -106,6 +106,9 @@ ifndef PLATFORM_RISCV_XLEN
   endif
 endif
 
+# Check whether the assembler and the compiler support the Zicsr and Zifencei extensions
+CC_SUPPORT_ZICSR_ZIFENCEI := $(shell $(CC) $(CLANG_TARGET) $(RELAX_FLAG) -nostdlib -march=rv$(OPENSBI_CC_XLEN)imafd_zicsr_zifencei -x c /dev/null -o /dev/null 2>&1 | grep "zicsr\|zifencei" > /dev/null && echo n || echo y)
+
 # Setup list of objects.mk files
 ifdef PLATFORM
 platform-object-mks=$(shell if [ -d $(platform_src_dir)/ ]; then find $(platform_src_dir) -iname "objects.mk" | sort -r; fi)
@@ -157,7 +160,11 @@ ifndef PLATFORM_RISCV_ABI
 endif
 ifndef PLATFORM_RISCV_ISA
   ifneq ($(PLATFORM_RISCV_TOOLCHAIN_DEFAULT), 1)
-    PLATFORM_RISCV_ISA = rv$(PLATFORM_RISCV_XLEN)imafdc
+    ifeq ($(CC_SUPPORT_ZICSR_ZIFENCEI), y)
+      PLATFORM_RISCV_ISA = rv$(PLATFORM_RISCV_XLEN)imafdc_zicsr_zifencei
+    else
+      PLATFORM_RISCV_ISA = rv$(PLATFORM_RISCV_XLEN)imafdc
+    endif
   else
     PLATFORM_RISCV_ISA = $(OPENSBI_CC_ISA)
   endif