Re: [Qemu-devel] [PATCH V9 2/4] tests/migration: Support cross compilation in generating boot header file

[Wei Huang]

----- Original Message -----
> From: "Andrew Jones" <address@hidden>
> To: "Wei Huang" <address@hidden>
> Cc: address@hidden, address@hidden, "peter maydell" <address@hidden>, 
> address@hidden,
> address@hidden, "alex bennee" <address@hidden>
> Sent: Thursday, September 6, 2018 7:03:32 AM
> Subject: Re: [Qemu-devel] [PATCH V9 2/4] tests/migration: Support cross 
> compilation in generating boot header file
> 
> On Wed, Sep 05, 2018 at 03:15:32PM -0400, Wei Huang wrote:
> > Recently a new configure option, CROSS_CC_GUEST, was added to
> > $(TARGET)-softmmu/config-target.mak to support TCG-related tests. This
> > patch tries to leverage this option to support cross compilation when the
> > migration boot block file is being re-generated:
> > 
> >  * The x86 related files are moved to a new sub-dir (named ./i386).
> >  * A new top-layer Makefile is created in tests/migration/ directory.
> >    This Makefile searches and parses CROSS_CC_GUEST to generate
> >    CROSS_PREFIX.
> >    The CROSS_PREFIX, if available, is then passed to
> >    migration/$ARCH/Makefile.
> > 
> > Reviewed-by: Juan Quintela <address@hidden>
> > Signed-off-by: Wei Huang <address@hidden>
> > ---
> >  tests/migration-test.c                             |  2 +-
> >  tests/migration/Makefile                           | 44
> >  ++++++++++++----------
> >  tests/migration/i386/Makefile                      | 22 +++++++++++
> >  .../{x86-a-b-bootblock.S => i386/a-b-bootblock.S}  |  4 --
> >  .../{x86-a-b-bootblock.h => i386/a-b-bootblock.h}  |  8 ++--
> >  5 files changed, 51 insertions(+), 29 deletions(-)
> >  create mode 100644 tests/migration/i386/Makefile
> >  rename tests/migration/{x86-a-b-bootblock.S => i386/a-b-bootblock.S} (93%)
> >  rename tests/migration/{x86-a-b-bootblock.h => i386/a-b-bootblock.h} (92%)
> > 
> > diff --git a/tests/migration-test.c b/tests/migration-test.c
> > index 0e687b7..fe6b41a 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/i386/a-b-bootblock.h"
> >  
> >  static void init_bootfile_x86(const char *bootpath)
> >  {
> > diff --git a/tests/migration/Makefile b/tests/migration/Makefile
> > index c0824b4..a9ed875 100644
> > --- a/tests/migration/Makefile
> > +++ b/tests/migration/Makefile
> > @@ -1,31 +1,35 @@
> > -# 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 = i386
> > +
> > +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/address@hidden Edit that file and then run "make all"
> > + * inside tests/migration to update, and then remember to send both
> > + * the header and the assembler differences 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 $@
> > +find-arch-cross-cc = $(lastword $(shell grep -h "CROSS_CC_GUEST="
> > $(wildcard $(SRC_PATH)/$(patsubst
> > i386,*86*,$(1))-softmmu/config-target.mak)))
> 
> The above function hangs unless configuring with
> '--target-list=x86_64-softmmu,aarch64-softmmu'. I tried just x86_64 alone,
> just aarch64 alone, and also configuring both x86_64 and i386, but none
> of those worked. For some reason grep isn't happy with the generated path
> list. I tested like this
> 
>  ./configure --target-list=x86_64-softmmu,i386-softmmu
>  make -C tests/migration
> 
> And, while not an issue of this series, I had to manually add
> CROSS_CC_GUEST="aarch64-linux-gnu-gcc" to aarch64-softmmu/config-target.mak
> for it to work, because configure's compiler test fails with the Fedora
> aarch64-linux-gnu-gcc installation (the linker can't find code it needs
> to a build a program with main()). I'm not sure if building programs with
> main() is something the CROSS_CC_GUEST compiler needs to do. Maybe that
> test can be relaxed. Alex?

I saw the same problem and it needs to be addressed in ./configure file. Most 
distros don't ship with
cross-compiled glibc. So compiling main() will fail because of that. 

> 
> Thanks,
> drew
> 
> > +parse-cross-prefix = $(subst gcc,,$(patsubst cc,gcc,$(patsubst
> > CROSS_CC_GUEST="%",%,$(call find-arch-cross-cc,$(1)))))
> > +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 $$target clean; \
> > +   done
> > diff --git a/tests/migration/i386/Makefile b/tests/migration/i386/Makefile
> > new file mode 100644
> > index 0000000..5c03241
> > --- /dev/null
> > +++ b/tests/migration/i386/Makefile
> > @@ -0,0 +1,22 @@
> > +# To specify cross compiler prefix, use CROSS_PREFIX=
> > +#   $ make CROSS_PREFIX=x86_64-linux-gnu-
> > +
> > +.PHONY: all clean
> > +all: a-b-bootblock.h
> > +
> > +a-b-bootblock.h: x86.bootsect
> > +   echo "$$__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: 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/i386/a-b-bootblock.S
> > similarity index 93%
> > rename from tests/migration/x86-a-b-bootblock.S
> > rename to tests/migration/i386/a-b-bootblock.S
> > index b164264..3f97f28 100644
> > --- a/tests/migration/x86-a-b-bootblock.S
> > +++ b/tests/migration/i386/a-b-bootblock.S
> > @@ -3,10 +3,6 @@
> >  #  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.
> > -#
> >  # 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.
> >  # See the COPYING file in the top-level directory.
> > diff --git a/tests/migration/x86-a-b-bootblock.h
> > b/tests/migration/i386/a-b-bootblock.h
> > similarity index 92%
> > rename from tests/migration/x86-a-b-bootblock.h
> > rename to tests/migration/i386/a-b-bootblock.h
> > index 78a151f..7d459d4 100644
> > --- a/tests/migration/x86-a-b-bootblock.h
> > +++ b/tests/migration/i386/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/i386. Edit that file and then run "make all"
> > + * inside tests/migration to update, and then remember to send both
> > + * the header and the assembler differences in your patch submission.
> >   */
> >  unsigned char x86_bootsect[] = {
> >    0xfa, 0x0f, 0x01, 0x16, 0x74, 0x7c, 0x66, 0xb8, 0x01, 0x00, 0x00, 0x00,
> > --
> > 1.8.3.1
> > 
> > 
>