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:
> 
> 
> On 02/26/2018 12:01 PM, Dr. David Alan Gilbert wrote:
> > * 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.
> 
> I think it is fine. If no cross compiler is present, NNN_cross_prefix
> won't find anything. So it ends up with using the gcc tools on host
> systems. Obviously the compilation will fail. This should become the
> problem to solve for whoever wants to do cross-compile. For us, we have
> done our part because the .h files have been provided.

But isn't it a problem for people just trying to make check?
One of the things that convinced me to move it out of the makefile and
into a separate script was that it was too easy to get into a situation
where Make wanted to rebuild the headerilfe on a system.

Dave

> > 
> > 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
> > 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK