From 9da71839fdc4e8b9d034998b0ed8a7ee9dfe7645 Mon Sep 17 00:00:00 2001
From: Thomas Huth <thuth@redhat.com>
Date: Sun, 2 May 2021 13:22:21 +0200
Subject: [PATCH 34/39] pc-bios/s390-ccw: Allow building with Clang, too
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RH-Author: Jon Maloy <jmaloy@redhat.com>
RH-MergeRequest: 24: v7: Add support for building qemu-kvm with clang and safe-stack
RH-Commit: [7/11] d7c510f1e5f6434f6b3e4bab5b5f75403cbc7e1b (jmaloy/qemu-kvm-centos-jon)
RH-Bugzilla: 1939509 1940132
RH-Acked-by: Danilo Cesar Lemes de Paula <ddepaula@redhat.com>
RH-Acked-by: Thomas Huth <thuth@redhat.com>
RH-Acked-by: Cornelia Huck <cohuck@redhat.com>
Clang unfortunately does not support generating code for the z900
architecture level and starts with the z10 instead. Thus to be able
to support compiling with Clang, we have to check for the supported
compiler flags. The disadvantage is of course that the bios image
will only run with z10 guest CPUs upwards (which is what most people
use anyway), so just in case let's also emit a warning in that case
(we will continue to ship firmware images that have been pre-built
with GCC in future releases, so this should not impact normal users,
too).
Message-Id: <20210502174836.838816-5-thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
(cherry picked from commit a5b2afd522dde375c38cf94b7c696ffa3faba2fb)
Signed-off-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
configure | 9 ++++++++-
pc-bios/s390-ccw/Makefile | 3 ++-
2 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/configure b/configure
index 7edc08afb3..83d8af7fe4 100755
--- a/configure
+++ b/configure
@@ -5424,9 +5424,16 @@ if { test "$cpu" = "i386" || test "$cpu" = "x86_64"; } && \
fi
# Only build s390-ccw bios if we're on s390x and the compiler has -march=z900
+# or -march=z10 (which is the lowest architecture level that Clang supports)
if test "$cpu" = "s390x" ; then
write_c_skeleton
- if compile_prog "-march=z900" ""; then
+ compile_prog "-march=z900" ""
+ has_z900=$?
+ if [ $has_z900 = 0 ] || compile_prog "-march=z10" ""; then
+ if [ $has_z900 != 0 ]; then
+ echo "WARNING: Your compiler does not support the z900!"
+ echo " The s390-ccw bios will only work with guest CPUs >= z10."
+ fi
roms="$roms s390-ccw"
# SLOF is required for building the s390-ccw firmware on s390x,
# since it is using the libnet code from SLOF for network booting.
diff --git a/pc-bios/s390-ccw/Makefile b/pc-bios/s390-ccw/Makefile
index 83fb1afb73..cee9d2c63b 100644
--- a/pc-bios/s390-ccw/Makefile
+++ b/pc-bios/s390-ccw/Makefile
@@ -34,7 +34,8 @@ QEMU_CFLAGS += $(call cc-option,-Werror $(QEMU_CFLAGS),-Wno-stringop-overflow)
QEMU_CFLAGS += -ffreestanding -fno-delete-null-pointer-checks -fno-common -fPIE
QEMU_CFLAGS += -fwrapv -fno-strict-aliasing -fno-asynchronous-unwind-tables
QEMU_CFLAGS += $(call cc-option, $(QEMU_CFLAGS), -fno-stack-protector)
-QEMU_CFLAGS += -msoft-float -march=z900
+QEMU_CFLAGS += -msoft-float
+QEMU_CFLAGS += $(call cc-option, $(QEMU_CFLAGS),-march=z900,-march=z10)
QEMU_CFLAGS += -std=gnu99
LDFLAGS += -Wl,-pie -nostdlib
--
2.27.0