From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnout Vandecappelle Date: Mon, 10 Feb 2014 18:06:31 +0100 Subject: [Buildroot] [PATCH] qemu: add host/target Linux version check In-Reply-To: <1391896471-28299-1-git-send-email-fhunleth@troodon-software.com> References: <1391896471-28299-1-git-send-email-fhunleth@troodon-software.com> Message-ID: <52F90717.6010103@mind.be> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net On 02/08/14 22:54, Frank Hunleth wrote: > Raise an error if the host is using an older kernel than the target. > Since qemu-user passes emulated system calls to the host kernel, > this prevents usage of qemu-user in situations where those system > calls will fail. > > Signed-off-by: Frank Hunleth Thanks Frank! > --- > package/qemu/qemu.mk | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > > diff --git a/package/qemu/qemu.mk b/package/qemu/qemu.mk > index 093ae64..bd6f555 100644 > --- a/package/qemu/qemu.mk > +++ b/package/qemu/qemu.mk > @@ -74,6 +74,24 @@ define HOST_QEMU_CONFIGURE_CMDS > ) > endef > > +define HOST_QEMU_LINUX_VERSION_CHECK Just to be sure, I'd start with a test `uname -s` = Linux (some people try to run buildroot on *BSDs, with varying degrees of success). > + host_version_parts=`uname -r | sed 's/\-.*//g' | sed 's/\./ /g'` ;\ > + host_version_code=0 ;\ > + multiplier=65536 ;\ > + for host_version_part in $$host_version_parts; do \ > + host_version_code=`echo "$$host_version_code + $$host_version_part * $$multiplier" | bc` ;\ > + multiplier=`echo "$$multiplier / 256" | bc` ;\ Even though we do put bc in our dependencies, I'd prefer to avoid relying on it - not many people know it. Instead, I'd use either bash's let builtin, or POSIX-compliant expr. > + done ;\ > + target_version_code=`grep LINUX_VERSION_CODE $(STAGING_DIR)/usr/include/linux/version.h | awk '{print $$3}'` ;\ You can do the grep inside the awk: awk '/LINUX_VERSION_CODE/ {print $$3}' .../version.h Since it is possible to build host-qemu without building anything for the target, you can't rely on version.h being present already. To make sure it is there, add toolchain to the HOST_QEMU_DEPENDENCIES. > + if test $$host_version_code -lt $$target_version_code ; then \ > + echo "Refusing to install qemu-user since the target Linux version is newer" ;\ > + echo "than the host's. Missing system calls will fail." ;\ > + exit 1 ;\ > + fi > +endef > + > +HOST_QEMU_POST_BUILD_HOOKS += HOST_QEMU_LINUX_VERSION_CHECK I think a pre-configure hook is more appropriate. Regards, Arnout > + > $(eval $(host-autotools-package)) > > # variable used by other packages > -- Arnout Vandecappelle arnout at mind be Senior Embedded Software Architect +32-16-286500 Essensium/Mind http://www.mind.be G.Geenslaan 9, 3001 Leuven, Belgium BE 872 984 063 RPR Leuven LinkedIn profile: http://www.linkedin.com/in/arnoutvandecappelle GPG fingerprint: 7CB5 E4CC 6C2E EFD4 6E3D A754 F963 ECAB 2450 2F1F