Re: [Qemu-devel] [PATCH V8 2/4] tests/migration: Support cross compilation in generating boot header file

[Andrew Jones]

On Sat, Sep 01, 2018 at 01:11:13AM -0400, Wei Huang wrote:
> Recently a new configure option, CROSS_CC_GUEST, was added to
> $(TARGET)-softmmu/config-target.mak to support TCG-related tests. This
> patch tries to leverage this option to support cross compilation when the
> migration boot block file is being re-generated:
> 
>  * The x86_64 related files are moved to a new sub-dir (named ./x86_64).
>  * A new top-layer Makefile is created in tests/migration/ directory.
>    This Makefile searches and parses CROSS_CC_GUEST to generate CROSS_PREFIX.
>    The CROSS_PREFIX, if available, is then passed to migration/$ARCH/Makefile.
> 
> Signed-off-by: Wei Huang <address@hidden>
> ---
>  tests/migration-test.c                           |  2 +-
>  tests/migration/Makefile                         | 43 
> +++++++++++++-----------
>  tests/migration/x86_64/Makefile                  | 22 ++++++++++++
>  tests/migration/{ => x86_64}/x86-a-b-bootblock.S |  0
>  tests/migration/{ => x86_64}/x86-a-b-bootblock.h |  8 ++---
>  5 files changed, 50 insertions(+), 25 deletions(-)
>  create mode 100644 tests/migration/x86_64/Makefile
>  rename tests/migration/{ => x86_64}/x86-a-b-bootblock.S (100%)
>  rename tests/migration/{ => x86_64}/x86-a-b-bootblock.h (93%)
> 
> diff --git a/tests/migration-test.c b/tests/migration-test.c
> index 0e687b7..c4d79e9 100644
> --- a/tests/migration-test.c
> +++ b/tests/migration-test.c
> @@ -83,7 +83,7 @@ static const char *tmpfs;
>  /* A simple PC boot sector that modifies memory (1-100MB) quickly
>   * outputting a 'B' every so often if it's still running.
>   */
> -#include "tests/migration/x86-a-b-bootblock.h"
> +#include "tests/migration/x86_64/x86-a-b-bootblock.h"

Is x86-a-b-bootblock.h specific to x86_64, or both i386 and x86_64?
I think we want the dir name to be i386 if it's the later. Also,
we could drop the 'x86-' prefix from the filename, now that the
directory identifies the arch.

>  
>  static void init_bootfile_x86(const char *bootpath)
>  {
> diff --git a/tests/migration/Makefile b/tests/migration/Makefile
> index 5d5fa07..1de480e 100644
> --- a/tests/migration/Makefile
> +++ b/tests/migration/Makefile
> @@ -1,31 +1,34 @@
> -# To specify cross compiler prefix, use CROSS_PREFIX=
> -#   > make CROSS_PREFIX=x86_64-linux-gnu-
> +#
> +# Copyright (c) 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.
> +#
> +
> +TARGET_LIST = x86_64
> +
> +SRC_PATH = ../..
>  
>  override define __note
> -/* 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.
> +/* This file is automatically generated from the assembly file in
> + * tests/migration/$@, edit that and then run "make all"

nit: /, edit that/. Edit that file/

> + * inside tests/migration to update, and then remember to send both
> + * in your patch submission.
nit: ^ the header and the assembler differences

>   */
>  endef
>  export __note
>  
> -.PHONY: all clean
> -all: x86-a-b-bootblock.h
> -
> -x86-a-b-bootblock.h: x86.bootsect
> -     echo "$$__note" > header.tmp
> -     xxd -i $< | sed -e 's/.*int.*//' >> header.tmp
> -     mv header.tmp $@
> +parse-cross-prefix = $(subst gcc,,$(patsubst cc,gcc,$(patsubst 
> CROSS_CC_GUEST="%",%,$(shell grep "CROSS_CC_GUEST=" 
> $(SRC_PATH)/$(1)-softmmu/config-target.mak))))
> +gen-cross-prefix = $(patsubst %-,CROSS_PREFIX=%-,$(call 
> parse-cross-prefix,$(1)))
>  
> -x86.bootsect: x86.boot
> -     dd if=$< of=$@ bs=256 count=2 skip=124
> +.PHONY: all $(TARGET_LIST)
>  
> -x86.boot: x86.o
> -     $(CROSS_PREFIX)objcopy -O binary $< $@
> +all: $(TARGET_LIST)
>  
> -x86.o: x86-a-b-bootblock.S
> -     $(CROSS_PREFIX)gcc -m32 -march=i486 -c $< -o $@
> +$(TARGET_LIST):
> +     $(MAKE) -C $@ $(call gen-cross-prefix,$@)
>  
>  clean:
> -     @rm -rf *.boot *.o *.bootsect
> +     for target in $(TARGET_LIST); do \
> +             $(MAKE) -C $$target clean; \
> +     done

The above seems overly complicated. Does the following work?

$(TARGET_LIST): CROSS_PREFIX=$(CROSS_CC_GUEST)
$(TARGET_LIST):
        $(MAKE) -C $@


> diff --git a/tests/migration/x86_64/Makefile b/tests/migration/x86_64/Makefile
> new file mode 100644
> index 0000000..6dc849f
> --- /dev/null
> +++ b/tests/migration/x86_64/Makefile
> @@ -0,0 +1,22 @@
> +# To specify cross compiler prefix, use CROSS_PREFIX=
> +#   > make CROSS_PREFIX=x86_64-linux-gnu-
> +
> +.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 $@
> +
> +x86.bootsect: x86.boot
> +     dd if=$< 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
> diff --git a/tests/migration/x86-a-b-bootblock.S 
> b/tests/migration/x86_64/x86-a-b-bootblock.S
> similarity index 100%
> rename from tests/migration/x86-a-b-bootblock.S
> rename to tests/migration/x86_64/x86-a-b-bootblock.S
> diff --git a/tests/migration/x86-a-b-bootblock.h 
> b/tests/migration/x86_64/x86-a-b-bootblock.h
> similarity index 93%
> rename from tests/migration/x86-a-b-bootblock.h
> rename to tests/migration/x86_64/x86-a-b-bootblock.h
> index 78a151f..73670ef 100644
> --- a/tests/migration/x86-a-b-bootblock.h
> +++ b/tests/migration/x86_64/x86-a-b-bootblock.h
> @@ -1,7 +1,7 @@
> -/* 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.
> +/* This file is automatically generated from the assembly file in
> + * tests/migration/x86_64, edit that and then run "make all"
> + * inside tests/migration to update, and then remember to send both
> + * in your patch submission.
>   */
>  unsigned char x86_bootsect[] = {
>    0xfa, 0x0f, 0x01, 0x16, 0x74, 0x7c, 0x66, 0xb8, 0x01, 0x00, 0x00, 0x00,
> -- 
> 1.8.3.1
> 
>

Thanks,
drew