Re: [Qemu-devel] [PATCH V7 2/4] tests/migration: Convert the boot block compilation script into Makefile

[Laurent Vivier <lvivier@redhat.com>]

On 28/02/2018 19:02, Wei Huang wrote:
> The x86 boot block header currently is generated with a shell script.
> To better support other CPUs (e.g. aarch64), we convert the script
> into Makefile. This allows us to 1) support cross-compilation easily,
> and 2) avoid creating a script file for every architecture.
> 
> Signed-off-by: Wei Huang <wei@redhat.com>
> Reviewed-by: Andrew Jones <drjones@redhat.com>
> ---
>  tests/migration/Makefile                 | 36 ++++++++++++++++++++++++++++++++
>  tests/migration/rebuild-x86-bootblock.sh | 33 -----------------------------
>  tests/migration/x86-a-b-bootblock.h      |  2 +-
>  tests/migration/x86-a-b-bootblock.s      |  5 ++---
>  4 files changed, 39 insertions(+), 37 deletions(-)
>  create mode 100644 tests/migration/Makefile
>  delete mode 100755 tests/migration/rebuild-x86-bootblock.sh
> 
> diff --git a/tests/migration/Makefile b/tests/migration/Makefile
> new file mode 100644
> index 0000000000..8fbedaa8b8
> --- /dev/null
> +++ b/tests/migration/Makefile
> @@ -0,0 +1,36 @@
> +#
> +# Copyright (c) 2016-2018 Red Hat, Inc. and/or its affiliates
> +#
> +# Authors:
> +#   Dave Gilbert <dgilbert@redhat.com>
> +#
> +# This work is licensed under the terms of the GNU GPL, version 2 or later.
> +# See the COPYING file in the top-level directory.
> +#
> +export __note
> +override define __note
> +/* This file is automatically generated from
> + * tests/migration/$<, edit that and then run
> + * "make $@" inside tests/migration to update,
> + * and then remember to send both in your patch submission.
> + */
> +endef
> +
> +all: x86-a-b-bootblock.h
> +# Dummy command so that make thinks it has done something
> +	@true
> +
> +SRC_PATH=../..
> +include $(SRC_PATH)/rules.mak

does it work in not in-tree build?

> +
> +x86_64_cross_prefix := $(call find-cross-prefix,x86_64)
> +
> +x86-a-b-bootblock.h: x86-a-b-bootblock.s
> +	$(x86_64_cross_prefix)as --32 -march=i486 $< -o x86.o
> +	$(x86_64_cross_prefix)objcopy -O binary x86.o x86.boot
> +	dd if=x86.boot of=x86.bootsect bs=256 count=2 skip=124
> +	echo "$$__note" > $@
> +	xxd -i x86.bootsect | sed -e 's/.*int.*//' >> $@

To be really in the spirit of a makefile, you should have a rule by target:

x86.o: x86-a-b-bootblock.s
	$(x86_64_cross_prefix)as --32 -march=i486 $< -o x86.o

x86.boot: x86.o
	$(x86_64_cross_prefix)objcopy -O binary x86.o x86.boot

x86.bootsect: x86.boot
	dd if=x86.boot of=x86.bootsect bs=256 count=2 skip=124

x86-a-b-bootblock.h: x86.bootsect
	echo "$$__note" > header.tmp
	xxd -i x86.bootsect | sed -e 's/.*int.*//' >> header.tmp
	mv header.tmp $@

Thanks,
Laurent