Re: [Qemu-devel] [PATCH V8 1/4] tests/migration: Convert x86 boot block compilation script into Makefile

[Andrew Jones <drjones@redhat.com>]

On Sat, Sep 01, 2018 at 01:11:12AM -0400, 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.
> 
> Note that, in the new design, the cross compiler prefix can be specified by
> setting the CROSS_PREFIX in "make" command. Also to allow gcc pre-processor
> to include the C-style file correctly, it also renames the
> x86-a-b-bootblock.s file extension from .s to .S.
> 
> Signed-off-by: Wei Huang <wei@redhat.com>
> ---
>  tests/migration/Makefile                           | 31 ++++++++++++++++++++
>  tests/migration/rebuild-x86-bootblock.sh           | 33 ----------------------
>  .../{x86-a-b-bootblock.s => x86-a-b-bootblock.S}   |  0
>  3 files changed, 31 insertions(+), 33 deletions(-)
>  create mode 100644 tests/migration/Makefile
>  delete mode 100755 tests/migration/rebuild-x86-bootblock.sh
>  rename tests/migration/{x86-a-b-bootblock.s => x86-a-b-bootblock.S} (100%)
> 
> diff --git a/tests/migration/Makefile b/tests/migration/Makefile
> new file mode 100644
> index 0000000..5d5fa07
> --- /dev/null
> +++ b/tests/migration/Makefile
> @@ -0,0 +1,31 @@
> +# To specify cross compiler prefix, use CROSS_PREFIX=
> +#   > make CROSS_PREFIX=x86_64-linux-gnu-
       ^ nit: this prompt symbol is weird (at least to me, what shell uses
              this?) To me it looks like a sh/bash redirect symbol. Can
              we change it to '$' or use nothing at all?
> +
> +override define __note
> +/* This file is automatically generated from
> + * tests/migration/x86-a-b-bootblock.s, edit that and then run
                                        ^ should be 'S'

> + * tests/migration/rebuild-x86-bootblock.sh to update,
> + * and then remember to send both in your patch submission.
> + */
> +endef
> +export __note
> +
> +.PHONY: all clean
> +all: x86-a-b-bootblock.h
> +
> +x86-a-b-bootblock.h: x86.bootsect
> +	echo "$$__note" > header.tmp
> +	xxd -i $< | sed -e 's/.*int.*//' >> header.tmp
> +	mv header.tmp $@

The shell script this Makefile is replacing used mktemp
for a randomly named tmp dir. Shouldn't we continue to
use random names?

> +
> +x86.bootsect: x86.boot
> +	dd if=$< of=$@ bs=256 count=2 skip=124
> +
> +x86.boot: x86.o
> +	$(CROSS_PREFIX)objcopy -O binary $< $@
> +
> +x86.o: x86-a-b-bootblock.S
> +	$(CROSS_PREFIX)gcc -m32 -march=i486 -c $< -o $@
> +
> +clean:
> +	@rm -rf *.boot *.o *.bootsect

We don't want to remove the generated header file when cleaning?

> diff --git a/tests/migration/rebuild-x86-bootblock.sh b/tests/migration/rebuild-x86-bootblock.sh
> deleted file mode 100755
> index 86cec5d..0000000
> --- 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.s b/tests/migration/x86-a-b-bootblock.S
> similarity index 100%
> rename from tests/migration/x86-a-b-bootblock.s
> rename to tests/migration/x86-a-b-bootblock.S
> -- 
> 1.8.3.1
> 
>

Thanks,
drew