pc-bios/s390-ccw: Optimize the s390-netboot.img for size

The -O2 optimization flag is passed via CFLAGS to the firmware Makefile,
but in netbook.mak, we've got some rules that only use QEMU_CFLAGS for
compiling the libc and libnet from SLOF, so these files get compiled
without optimization so far. Use CFLAGS here, too, to create faster
and smaller code.

We can additionally save some more bytes in the firmware images by compi-
ling the code with -fno-asynchronous-unwind-tables. This will omit some
ELF sections (used for stack unwinding for example) from the image that
we do not need in the firmware.

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

diff --git a/pc-bios/s390-ccw/Makefile b/pc-bios/s390-ccw/Makefile
index 439e3cc9c9419aa3dbecbabe5a0d235ca57ec758..1eb316b02f1fab0d62667ab7f5a6646a6945ab36 100644 (file)
--- a/pc-bios/s390-ccw/Makefile
+++ b/pc-bios/s390-ccw/Makefile
@@ -15,6 +15,7 @@ OBJECTS = start.o main.o bootmap.o jump2ipl.o sclp.o menu.o \
 QEMU_CFLAGS := $(filter -W%, $(QEMU_CFLAGS))
 QEMU_CFLAGS += -ffreestanding -fno-delete-null-pointer-checks -msoft-float
 QEMU_CFLAGS += -march=z900 -fPIE -fno-strict-aliasing
+QEMU_CFLAGS += -fno-asynchronous-unwind-tables
 QEMU_CFLAGS += $(call cc-option, $(QEMU_CFLAGS), -fno-stack-protector)
 LDFLAGS += -Wl,-pie -nostdlib
 

diff --git a/pc-bios/s390-ccw/netboot.mak b/pc-bios/s390-ccw/netboot.mak
index 8af0cfd2dad953b1492ac5df02b6a2474fe84410..14e96b2aa611905cbf9fdaa3b8ab0a7b3ee68fc3 100644 (file)
--- a/pc-bios/s390-ccw/netboot.mak
+++ b/pc-bios/s390-ccw/netboot.mak
@@ -19,7 +19,7 @@ s390-netboot.img: s390-netboot.elf
 
 # libc files:
 
-LIBC_CFLAGS :=  $(QEMU_CFLAGS) $(LIBC_INC) $(LIBNET_INC)
+LIBC_CFLAGS :=  $(QEMU_CFLAGS) $(CFLAGS) $(LIBC_INC) $(LIBNET_INC)
 
 CTYPE_OBJS = isdigit.o isxdigit.o toupper.o
 %.o : $(SLOF_DIR)/lib/libc/ctype/%.c
@@ -52,7 +52,7 @@ libc.a: $(LIBCOBJS)
 
 LIBNETOBJS := args.o dhcp.o dns.o icmpv6.o ipv6.o tcp.o udp.o bootp.o \
              dhcpv6.o ethernet.o ipv4.o ndp.o tftp.o pxelinux.o
-LIBNETCFLAGS := $(QEMU_CFLAGS) -DDHCPARCH=0x1F $(LIBC_INC) $(LIBNET_INC)
+LIBNETCFLAGS := $(QEMU_CFLAGS) $(CFLAGS) -DDHCPARCH=0x1F $(LIBC_INC) $(LIBNET_INC)
 
 %.o : $(SLOF_DIR)/lib/libnet/%.c
        $(call quiet-command,$(CC) $(LIBNETCFLAGS) -c -o $@ $<,"CC","$(TARGET_DIR)$@")