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

[Wei Huang]

On 02/26/2018 12:01 PM, Dr. David Alan Gilbert wrote:
> * Wei Huang (address@hidden) 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 <address@hidden>
> 
> 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.

> 
> 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 <address@hidden>
>> +#
>> +# 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.*//' >> $@
>> +
>> +clean:
>> +    rm -f *.bootsect *.boot *.o
>> diff --git a/tests/migration/rebuild-x86-bootblock.sh 
>> b/tests/migration/rebuild-x86-bootblock.sh
>> deleted file mode 100755
>> index 86cec5d284..0000000000
>> --- a/tests/migration/rebuild-x86-bootblock.sh
>> +++ /dev/null
>> @@ -1,33 +0,0 @@
>> -#!/bin/sh
>> -# Copyright (c) 2016-2018 Red Hat, Inc. and/or its affiliates
>> -# This work is licensed under the terms of the GNU GPL, version 2 or later.
>> -# See the COPYING file in the top-level directory.
>> -#
>> -# Author: address@hidden
>> -
>> -ASMFILE=$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 / address@hidden / Manchester, UK
>