[PATCH 1/1] BaseTools: Fix RISC-V build failure with binutils 2.38+

["Sunil V L" <sunilvl@ventanamicro.com>]

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4061

>From version 2.38, binutils adheres to RISC-V ISA spec version
20191213. This means that the csr read/write (csrr*/csrw*)
instructions and fence.i instruction are separated from the
`I` extension, become two standalone extensions: Zicsr and
Zifencei. As the edk2 uses those instructions, this causes the
following build failure:

.../RiscV64/FlushCache.iiii:16: Error: unrecognized opcode `fence.i'

Hence, different -march strings are needed for different versions of
the toolchain. To support both types of the toolchains, detect
the capability of the toolchain while creating tools_def.txt from
the template and update the tools_def.txt with a different -march
string matching the toolchain capabilities.

Cc: Bob Feng <bob.c.feng@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Yuwei Chen <yuwei.chen@intel.com>
Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
---
 BaseTools/BuildEnv | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/BaseTools/BuildEnv b/BaseTools/BuildEnv
index 275f4c5901aa..08ab28107d89 100755
--- a/BaseTools/BuildEnv
+++ b/BaseTools/BuildEnv
@@ -213,6 +213,26 @@ AddEdkToolsToPath() {
 
 }
 
+UpdateRiscVToolsDefFile() {
+
+  # binutils 2.38+ needs zicsr_zifencei in -march
+  # To support older toolchain, run gcc with latest -march
+  # and check if it succeeds
+  ${GCC5_RISCV64_PREFIX}gcc -march=rv64imafdc_zicsr_zifencei -x c -c /dev/null \
+                  -o $CONF_PATH/TmpZicsrZifencei > /dev/null 2>&1
+  ZicsrZifenceiNeeded=$?
+
+  if [ $ZicsrZifenceiNeeded -eq 0 ]
+  then
+    echo "Updating $CONF_PATH/tools_def.txt"
+    sed -i 's/rv64imafdc/rv64imafdc_zicsr_zifencei/g' $CONF_PATH/tools_def.txt
+
+    # Remove the temporary file
+    rm $CONF_PATH/TmpZicsrZifencei
+  fi
+
+}
+
 CopySingleTemplateFile() {
 
   SRC_FILENAME=Conf/$1.template
@@ -228,6 +248,15 @@ CopySingleTemplateFile() {
   SRC_FILENAME=$EDK_TOOLS_PATH/$SRC_FILENAME
   cp $SRC_FILENAME $DST_FILENAME
 
+  # Update RISC-V definitions based on toolchain capabilities
+  if [ "$1" = "tools_def" ]
+  then
+    if ! [ -z ${GCC5_RISCV64_PREFIX} ]
+    then
+      UpdateRiscVToolsDefFile
+    fi
+  fi
+
 }
 
 CopyTemplateFiles() {
-- 
2.34.1