Re: [Qemu-devel] [PATCH V5 2/4] tests/migration: Convert the boot block compilation script into Makefile

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Wei Huang (wei@redhat.com) 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>

But what happens if you're on a system that doesn't have the cross
compilers?  I found it's too easy to get stuck with it trying
to rebuild the header when there's no need.

Dave

> ---
>  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
> +
> +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.*//' >> $@
> +
> +clean:
> +	rm -f *.bootsect *.boot *.o
> diff --git a/tests/migration/rebuild-x86-bootblock.sh b/tests/migration/rebuild-x86-bootblock.sh
> deleted file mode 100755
> index 86cec5d284..0000000000
> --- a/tests/migration/rebuild-x86-bootblock.sh
> +++ /dev/null
> @@ -1,33 +0,0 @@
> -#!/bin/sh
> -# Copyright (c) 2016-2018 Red Hat, Inc. and/or its affiliates
> -# This work is licensed under the terms of the GNU GPL, version 2 or later.
> -# See the COPYING file in the top-level directory.
> -#
> -# Author: dgilbert@redhat.com
> -
> -ASMFILE=$PWD/tests/migration/x86-a-b-bootblock.s
> -HEADER=$PWD/tests/migration/x86-a-b-bootblock.h
> -
> -if [ ! -e "$ASMFILE" ]
> -then
> -  echo "Couldn't find $ASMFILE" >&2
> -  exit 1
> -fi
> -
> -ASM_WORK_DIR=$(mktemp -d --tmpdir X86BB.XXXXXX)
> -cd "$ASM_WORK_DIR" &&
> -as --32 -march=i486 "$ASMFILE" -o x86.o &&
> -objcopy -O binary x86.o x86.boot &&
> -dd if=x86.boot of=x86.bootsect bs=256 count=2 skip=124 &&
> -xxd -i x86.bootsect |
> -sed -e 's/.*int.*//' > x86.hex &&
> -cat - x86.hex <<HERE > "$HEADER"
> -/* This file is automatically generated from
> - * tests/migration/x86-a-b-bootblock.s, edit that and then run
> - * tests/migration/rebuild-x86-bootblock.sh to update,
> - * and then remember to send both in your patch submission.
> - */
> -HERE
> -
> -rm x86.hex x86.bootsect x86.boot x86.o
> -cd .. && rmdir "$ASM_WORK_DIR"
> diff --git a/tests/migration/x86-a-b-bootblock.h b/tests/migration/x86-a-b-bootblock.h
> index 78a151fe2a..9e8e2e028b 100644
> --- a/tests/migration/x86-a-b-bootblock.h
> +++ b/tests/migration/x86-a-b-bootblock.h
> @@ -1,6 +1,6 @@
>  /* This file is automatically generated from
>   * tests/migration/x86-a-b-bootblock.s, edit that and then run
> - * tests/migration/rebuild-x86-bootblock.sh to update,
> + * "make x86-a-b-bootblock.h" inside tests/migration to update,
>   * and then remember to send both in your patch submission.
>   */
>  unsigned char x86_bootsect[] = {
> diff --git a/tests/migration/x86-a-b-bootblock.s b/tests/migration/x86-a-b-bootblock.s
> index b1642641a7..98dbfab084 100644
> --- a/tests/migration/x86-a-b-bootblock.s
> +++ b/tests/migration/x86-a-b-bootblock.s
> @@ -3,9 +3,8 @@
>  #  range.
>  #  Outputs an initial 'A' on serial followed by repeated 'B's
>  #
> -# run   tests/migration/rebuild-x86-bootblock.sh
> -#   to regenerate the hex, and remember to include both the .h and .s
> -#   in any patches.
> +#  In tests/migration dir, run 'make x86-a-b-bootblock.h' to regenerate
> +#  the hex, and remember to include both the .h and .s in any patches.
>  #
>  # Copyright (c) 2016 Red Hat, Inc. and/or its affiliates
>  # This work is licensed under the terms of the GNU GPL, version 2 or later.
> -- 
> 2.14.3
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK