[PATCH v1 3/3] pc-bios/s390-ccw: Introduce `EXTRA_LDFLAGS`

[Marc Hartmayer <mhartmay@linux.ibm.com>]

Some packaging tools want to override `LDFLAGS` when building QEMU, this will
result in a build error as most likely no `-nostdlib` flag is passed. Introduce
`EXTRA_LDFLAGS` so that the packager can override `LDFLAGS` without breaking the
build.

Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
---
Note: Normally, I would rather use ALL_LDFLAGS, but adding EXTRA_LDFLAGS matches
      with the current Makefile style.
---
 pc-bios/s390-ccw/netboot.mak | 2 +-
 pc-bios/s390-ccw/Makefile    | 5 +++--
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/pc-bios/s390-ccw/netboot.mak b/pc-bios/s390-ccw/netboot.mak
index 046aa35587ac..b1bc12603d99 100644
--- a/pc-bios/s390-ccw/netboot.mak
+++ b/pc-bios/s390-ccw/netboot.mak
@@ -6,7 +6,7 @@ NETOBJS := start.o sclp.o cio.o virtio.o virtio-net.o jump2ipl.o netmain.o
 LIBC_INC := -nostdinc -I$(SLOF_DIR)/lib/libc/include
 LIBNET_INC := -I$(SLOF_DIR)/lib/libnet
 
-NETLDFLAGS := $(LDFLAGS) -Wl,-Ttext=0x7800000
+NETLDFLAGS := $(EXTRA_LDFLAGS) $(LDFLAGS) -Wl,-Ttext=0x7800000
 
 $(NETOBJS): EXTRA_CFLAGS += $(LIBC_INC) $(LIBNET_INC)
 
diff --git a/pc-bios/s390-ccw/Makefile b/pc-bios/s390-ccw/Makefile
index ab6bd1edf41e..56c971462992 100644
--- a/pc-bios/s390-ccw/Makefile
+++ b/pc-bios/s390-ccw/Makefile
@@ -4,6 +4,7 @@ all: build-all
 
 include config-host.mak
 CFLAGS = -O2 -g
+LDFLAGS ?=
 MAKEFLAGS += -rR
 
 GIT_SUBMODULES = roms/SLOF
@@ -40,7 +41,7 @@ EXTRA_CFLAGS += -ffreestanding -fno-delete-null-pointer-checks -fno-common -fPIE
 EXTRA_CFLAGS += -fwrapv -fno-strict-aliasing -fno-asynchronous-unwind-tables
 EXTRA_CFLAGS += -msoft-float
 EXTRA_CFLAGS += -std=gnu99
-LDFLAGS += -Wl,-pie -nostdlib -z noexecstack -z text
+EXTRA_LDFLAGS += -Wl,-pie -nostdlib -z noexecstack -z text
 
 cc-test = $(CC) -Werror $1 -c -o /dev/null -xc /dev/null >/dev/null 2>/dev/null
 cc-option = if $(call cc-test, $1); then \
@@ -58,7 +59,7 @@ config-cc.mak: Makefile
 build-all: s390-ccw.img s390-netboot.img
 
 s390-ccw.elf: $(OBJECTS)
-	$(call quiet-command,$(CC) $(LDFLAGS) -o $@ $(OBJECTS),Linking)
+	$(call quiet-command,$(CC) $(EXTRA_LDFLAGS) $(LDFLAGS) -o $@ $(OBJECTS),Linking)
 
 s390-ccw.img: s390-ccw.elf
 	$(call quiet-command,$(STRIP) --strip-unneeded $< -o $@,Stripping $< into)
-- 
2.43.0