The main QEMU code is compiled with -std=gnu99, -fwrapv and -fno-common.
We should use the same flags for the s390-ccw bios, too, to avoid that
we get different behavior with different compiler versions that changed
their default settings in the course of time (it happened at least with
-std=... and -fno-common in the past already).

While we're at it, also group the other flags here in a little bit nicer
fashion: Move the two "-m" flags out of the "-f" area and specify them on
a separate line.

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 pc-bios/s390-ccw/Makefile | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/pc-bios/s390-ccw/Makefile b/pc-bios/s390-ccw/Makefile
index 50bc880272..9abb0ea4c0 100644
--- a/pc-bios/s390-ccw/Makefile
+++ b/pc-bios/s390-ccw/Makefile
@@ -13,10 +13,11 @@ OBJECTS = start.o main.o bootmap.o jump2ipl.o sclp.o menu.o \
 	  virtio.o virtio-scsi.o virtio-blkdev.o libc.o cio.o dasd-ipl.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 += -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 += -std=gnu99
 LDFLAGS += -Wl,-pie -nostdlib
 
 build-all: s390-ccw.img s390-netboot.img
-- 
2.18.1

On Tue, 28 Jul 2020 20:37:29 +0200
Thomas Huth <thuth@redhat.com> wrote:

> The main QEMU code is compiled with -std=gnu99, -fwrapv and
> -fno-common. We should use the same flags for the s390-ccw bios, too,
> to avoid that we get different behavior with different compiler
> versions that changed their default settings in the course of time
> (it happened at least with -std=... and -fno-common in the past
> already).
> 
> While we're at it, also group the other flags here in a little bit
> nicer fashion: Move the two "-m" flags out of the "-f" area and
> specify them on a separate line.
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>  pc-bios/s390-ccw/Makefile | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/pc-bios/s390-ccw/Makefile b/pc-bios/s390-ccw/Makefile
> index 50bc880272..9abb0ea4c0 100644
> --- a/pc-bios/s390-ccw/Makefile
> +++ b/pc-bios/s390-ccw/Makefile
> @@ -13,10 +13,11 @@ OBJECTS = start.o main.o bootmap.o jump2ipl.o
> sclp.o menu.o \ virtio.o virtio-scsi.o virtio-blkdev.o libc.o cio.o
> dasd-ipl.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 += -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 += -std=gnu99
>  LDFLAGS += -Wl,-pie -nostdlib
>  
>  build-all: s390-ccw.img s390-netboot.img

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>

On Tue, 28 Jul 2020 20:37:29 +0200
Thomas Huth <thuth@redhat.com> wrote:

> The main QEMU code is compiled with -std=gnu99, -fwrapv and -fno-common.
> We should use the same flags for the s390-ccw bios, too, to avoid that
> we get different behavior with different compiler versions that changed
> their default settings in the course of time (it happened at least with
> -std=... and -fno-common in the past already).
> 
> While we're at it, also group the other flags here in a little bit nicer
> fashion: Move the two "-m" flags out of the "-f" area and specify them on
> a separate line.
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>  pc-bios/s390-ccw/Makefile | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)

Commonality is good :)

Acked-by: Cornelia Huck <cohuck@redhat.com>

On 7/28/20 8:37 PM, Thomas Huth wrote:
> The main QEMU code is compiled with -std=gnu99, -fwrapv and -fno-common.
> We should use the same flags for the s390-ccw bios, too, to avoid that
> we get different behavior with different compiler versions that changed
> their default settings in the course of time (it happened at least with
> -std=... and -fno-common in the past already).
> 
> While we're at it, also group the other flags here in a little bit nicer
> fashion: Move the two "-m" flags out of the "-f" area and specify them on
> a separate line.
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>

What was the argument for z900 again? TCG?
Maybe we can also move to z10?

Anyway:
Acked-by: Janosch Frank <frankja@linux.ibm.com>


> ---
>  pc-bios/s390-ccw/Makefile | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/pc-bios/s390-ccw/Makefile b/pc-bios/s390-ccw/Makefile
> index 50bc880272..9abb0ea4c0 100644
> --- a/pc-bios/s390-ccw/Makefile
> +++ b/pc-bios/s390-ccw/Makefile
> @@ -13,10 +13,11 @@ OBJECTS = start.o main.o bootmap.o jump2ipl.o sclp.o menu.o \
>  	  virtio.o virtio-scsi.o virtio-blkdev.o libc.o cio.o dasd-ipl.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 += -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 += -std=gnu99
>  LDFLAGS += -Wl,-pie -nostdlib
>  
>  build-all: s390-ccw.img s390-netboot.img
> 

On 31/07/2020 09.46, Janosch Frank wrote:
> On 7/28/20 8:37 PM, Thomas Huth wrote:
>> The main QEMU code is compiled with -std=gnu99, -fwrapv and -fno-common.
>> We should use the same flags for the s390-ccw bios, too, to avoid that
>> we get different behavior with different compiler versions that changed
>> their default settings in the course of time (it happened at least with
>> -std=... and -fno-common in the past already).
>>
>> While we're at it, also group the other flags here in a little bit nicer
>> fashion: Move the two "-m" flags out of the "-f" area and specify them on
>> a separate line.
>>
>> Signed-off-by: Thomas Huth <thuth@redhat.com>
> 
> What was the argument for z900 again? TCG?

Yes. As long as you can still select "-cpu z900" as parameter, the bios
should of course support that CPU level, too.

 Thomas