[PATCH v2 2/2] tools/firmware: do not add a .note.gnu.property section

[Roger Pau Monne <roger.pau@xxxxxxxxxx>]

Prevent the assembler from creating a .note.gnu.property section on
the output objects, as it's not useful for firmware related binaries,
and breaks the resulting rombios image.

This requires modifying the cc-option Makefile macro so it can test
assembler options (by replacing the usage of the -S flag with -c) and
also stripping the -Wa, prefix if present when checking for the test
output.

Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
Changes since v1:
 - Add the option to CFLAGS.
---
 Config.mk               | 2 +-
 tools/firmware/Rules.mk | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/Config.mk b/Config.mk
index f56f7dc334..82832945e5 100644
--- a/Config.mk
+++ b/Config.mk
@@ -91,7 +91,7 @@ PYTHON_PREFIX_ARG ?= --prefix="$(prefix)"
 #
 # Usage: cflags-y += $(call cc-option,$(CC),-march=winchip-c6,-march=i586)
 cc-option = $(shell if test -z "`echo 'void*p=1;' | \
-              $(1) $(2) -S -o /dev/null -x c - 2>&1 | grep -- $(2) -`"; \
+              $(1) $(2) -c -o /dev/null -x c - 2>&1 | grep -- 
$(2:-Wa$(comma)%=%) -`"; \
               then echo "$(2)"; else echo "$(3)"; fi ;)
 
 # cc-option-add: Add an option to compilation flags, but only if supported.
diff --git a/tools/firmware/Rules.mk b/tools/firmware/Rules.mk
index c227fe2524..278cca01e4 100644
--- a/tools/firmware/Rules.mk
+++ b/tools/firmware/Rules.mk
@@ -17,6 +17,10 @@ $(call cc-options-add,CFLAGS,CC,$(EMBEDDED_EXTRA_CFLAGS))
 
 $(call cc-option-add,CFLAGS,CC,-fcf-protection=none)
 
+# Do not add the .note.gnu.property section to any of the firmware objects: it
+# breaks the rombios binary and is not useful for firmware anyway.
+$(call cc-option-add,CFLAGS,CC,-Wa$$(comma)-mx86-used-note=no)
+
 # Extra CFLAGS suitable for an embedded type of environment.
 CFLAGS += -ffreestanding -msoft-float
 
-- 
2.35.1