[Buildroot] [PATCH v8 01/11] host-qemu: new package

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Fran?ois,

Thanks for keeping up the good work on this.

On Tue, 25 Sep 2012 19:18:17 +0200, Francois Perrad wrote:
> only user mode for the current target architecture
> 
> Signed-off-by: Francois Perrad <francois.perrad@gadz.org>
> ---
>  package/Config.in.host      |    1 +
>  package/qemu/Config.in.host |   15 +++++++++++++++
>  package/qemu/qemu.mk        |   43 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 59 insertions(+)
>  create mode 100644 package/qemu/Config.in.host
>  create mode 100644 package/qemu/qemu.mk
> 
> diff --git a/package/Config.in.host b/package/Config.in.host
> index 79050f2..bf95a10 100644
> --- a/package/Config.in.host
> +++ b/package/Config.in.host
> @@ -4,6 +4,7 @@ source "package/dfu-util/Config.in.host"
>  source "package/lpc3250loader/Config.in.host"
>  source "package/omap-u-boot-utils/Config.in.host"
>  source "package/openocd/Config.in.host"
> +source "package/qemu/Config.in.host"
>  source "package/sam-ba/Config.in.host"
>  source "package/uboot-tools/Config.in.host"
>  
> diff --git a/package/qemu/Config.in.host b/package/qemu/Config.in.host
> new file mode 100644
> index 0000000..379507c
> --- /dev/null
> +++ b/package/qemu/Config.in.host
> @@ -0,0 +1,15 @@
> +config BR2_PACKAGE_HOST_QEMU
> +	bool "host qemu"
> +	help
> +	  QEMU is a generic and open source machine emulator and virtualizer.
> +
> +	  In user mode emulation, QEMU runs single cross-compiled programs.
> +	  Fast cross-compilation and cross-debugging are the main targets
> +	  for user-mode emulation.
> +
> +	  In system mode emulation, QEMU emulates a full computer system,
> +	  including peripherals, and handles the filesystem image generated
> +	  by Buildroot.
> +	  (Buildroot is shipped with many configs/qemu_*_defconfig files).
> +
> +	  http://qemu.org/

I think you should not add a Kconfig option for the host-qemu package
for now. Until it supports the system emulation, it is kind of useless
to have it listed in the host tools. For the perl stuff, you only need
the user emulation, so let's add support for the user emulation only at
the moment.

> diff --git a/package/qemu/qemu.mk b/package/qemu/qemu.mk
> new file mode 100644
> index 0000000..d727f49
> --- /dev/null
> +++ b/package/qemu/qemu.mk
> @@ -0,0 +1,43 @@
> +#############################################################
> +#
> +# qemu
> +#
> +#############################################################
> +
> +QEMU_VERSION = 1.2.0
> +QEMU_SOURCE = qemu-$(QEMU_VERSION).tar.bz2
> +QEMU_SITE = http://wiki.qemu.org/download
> +
> +HOST_QEMU_DEPENDENCIES =

I think this is not needed.

> +
> +QEMU_ARCH=$(ARCH)
> +ifeq ($(QEMU_ARCH),i686)
> +    QEMU_ARCH=i386
> +endif
> +HOST_QEMU_TARGETS=$(QEMU_ARCH)-linux-user

This will not work for a number of architectures.

See the definition of BR2_ARCH in target/Config.in.arch. The list of
architectures you have to handle is:

	arm	-> no change
	armeb	-> no change
	avr32	-> not supported (so the perl package should depends on !BR2_avr32)
	bfin	-> not supported (so the perl package should depends on !BR2_bfin)
	i386	-> no change
	i486	-> change to i386
	i586	-> change to i386
	i686	-> change to i386
	x86_64	-> no change
	microblaze -> we probably have an issue here in
			target/Config.in.arch as we don't
			make the distinction between
			little endian and big endian
	mips		-> no change
	mipsel		-> no change
	mips64el	-> not sure what to do
	mips64		-> not sure what to do
	powerpc		-> change to ppc
	sh2		-> not supported (so perl should depends on !BR2_sh2)
	sh2a		-> ditto
	sh3		-> ditto
	sh4		-> no change
	sh4eb		-> no change
	sh4aeb		-> not sure, maybe sh4eb would work, but I don't know
	sh4a		-> not sure, same reason
	sh64		-> not supported (so perl should depends on !BR2_sh64)
	sparc		-> no change

So the definition of QEMU_ARCH needs to be made a bit more complicated.
Note: I wouldn't mind if you decide to exclude certain architectures
even if they might potentially work. We have to limit the development
work for a first version, otherwise we'll never get those patches
merged. So you could decide to support only i386, arm and maybe powerpc
for now, I would be fine with this.

> +define HOST_QEMU_CONFIGURE_CMDS
> +	(cd $(@D); ./configure                          \
> +		--target-list="$(HOST_QEMU_TARGETS)"    \
> +		--prefix="$(HOST_DIR)/usr"              \
> +		--interp-prefix=$(STAGING_DIR)          \
> +		--cc="$(HOSTCC)"                        \
> +		--host-cc="$(HOSTCC)"                   \
> +		--extra-cflags="$(HOST_CFLAGS)"         \
> +		--extra-ldflags="$(HOST_LDFLAGS)"       \
> +	)
> +endef
> +
> +define HOST_QEMU_BUILD_CMDS
> +	$(MAKE) -C $(@D) all
> +endef
> +
> +define HOST_QEMU_INSTALL_CMDS
> +	$(MAKE) -C $(@D) install
> +endef
> +
> +define HOST_QEMU_CLEAN_CMDS
> +	$(MAKE) -C $(@D) clean
> +endef
> +
> +$(eval $(host-generic-package))

The rest sounds ok to me. Shouldn't you pass a bunch of --disable-xxx
options in order to make sure that the Qemu ./configure script doesn't
pick up certain host libraries (SDL, etc.) ?

Best regards,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com