Re: [Qemu-devel] MINGW: Unable to link multiboot.img + strnlen missing

[Anthony Liguori <anthony@codemonkey.ws>]

Bartlomiej Celary wrote:
> Hi,
> I have recently updated my git snapshot and had 2 problems:
>   

Thanks for the report.

> 1. There is no strnlen function in MINGW (not sure if it has been
> added recently as I might be using an outdated version...)
>   

That should be easy enough to fix.  Can you send a patch?

> 2. I was not able to link multiboot.bin using mingw:
>
> for d in pc-bios/optionrom; do \
> make -C $d || exit 1 ; \
>         done
> make[1]: Entering directory `/home/abc024/work/qemu/pc-bios/optionrom'
> gcc -o signrom -g -Wall signrom.c
> gcc -Wall -Wstrict-prototypes -Werror -fomit-frame-pointer
> -fno-builtin -I/home/abc024/work/qemu -o multiboot.o -c multiboot.S
> ld --oformat binary -Ttext 0 -o multiboot.img multiboot.o
> D:\mingw\bin\ld.exe: cannot perform PE operations on non PE output
> file 'multiboot.img'.
> make[1]: *** [multiboot.img] Error 1
> rm multiboot.o
> make[1]: Leaving directory `/home/abc024/work/qemu/pc-bios/optionrom'
> make: *** [roms] Error 1
>
> And it looks that this workaround did the trick:
>
> diff --git a/pc-bios/optionrom/Makefile b/pc-bios/optionrom/Makefile
> old mode 100644
> new mode 100755
> index c4a6f42..f414eba
> --- a/pc-bios/optionrom/Makefile
> +++ b/pc-bios/optionrom/Makefile
> @@ -34,8 +34,14 @@ build-all: multiboot.bin
>  %.o: %.S
>         $(CC) $(CFLAGS) -o $@ -c $<
>
> -%.img: %.o
> -       $(LD) --oformat binary -Ttext 0 -o $@ $<
> +%.img: %.out
> +       $(OBJCOPY) -O binary -j .text $< $@
> +
> +%.out: %.o
> +       $(LD) -Ttext 0 -e _start -s -o $@ $<
>
>  %.bin: %.img signrom
>         ./signrom $< $@
>
> Obviously objcopy needs to be defined in the config.mak file.
>   

I'm not sure I understand why this works, but if you resubmit the patch 
with a Signed-off-by, we can apply it.

It's unfortunate that we need to do the signrom step now that I think 
about it as it's bad for cross-compilation.  Maybe we should sign 
anything without a checksum when doing option rom loading.  What do you 
think Alex?

Regards,

Anthony Liguori

> Regards,
> Bartek Celary
>
>
>