From c32ad51cbf2a9161f08880109099c78f6eab9116 Mon Sep 17 00:00:00 2001 From: "Yann E. MORIN" Date: Sat, 4 Aug 2018 10:27:41 +0200 Subject: [PATCH] core/sdk: generate the SDK tarball ourselves Currently, the wording in the manual instructs the user to generate a tarball from "the contents of the +output/host+ directory". This is pretty confusing, because taken literally, this would amount to running a command like: tar cf my-sdk.tar -C output/host/ . This creates a tarbomb [0], which is very bad practice, because when extracted, it creates multiple files in the current directory. What one really wants to do, is create a tarball of the host/ directory, with something like: tar cf my-sdk.tar -C output host/ However, this is not much better, because the top-most directory would have a very common name, host/, which is pretty easy to get conflict with when it gets extracted. So, we fix that mess by giving the top-most directory a recognisable name, based on the target tuple, which we also use as the name of the archive (suffixed with the usual +.tar.gz+.) We offer the user the possibility to override that default by specifying the +BR2_SDK_PREFIX+ variable on the command line. Since this is an output file, we place it in the images/ directory. As some users expressed a very strong feeling that they do not want to generate a tarball at all, and that doing so would badly hurt their workflows [1], we actually prepare the SDK as was previously done, but under the new, intermediate rule 'prepare-sdk'. The existing 'sdk' rule obviously depend on that before generating the tarball. We choose to make the existing rule to generate the tarball, and introduce a new rule to just prepare the SDK, rather than keep the existing rule as-is and introduce a new one to generate the tarball, because it makes sense to have the simplest rule do the correct thing, leaving advanced, power users use the longest command. If someone already had a wrapper that called 'sdk' and expected just the host directory to be prepared, then this is not broken; it just takes a bit longer (gzip is pretty fast). Update the manual accordingly. [0] https://en.wikipedia.org/wiki/Tar_(computing)#Tarbomb [1] http://lists.busybox.net/pipermail/buildroot/2018-June/thread.html#223377 and some messages in the ensuing thread... Signed-off-by: "Yann E. MORIN" Cc: Wolfgang Grandegger Cc: Thomas Petazzoni Cc: Arnout Vandecappelle Cc: Stefan Becker Cc: Trent Piepho Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Reviewed-by: Stefan Becker Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni --- Makefile | 15 +++++++++++-- docs/manual/using-buildroot-toolchain.txt | 26 +++++++++++++++-------- 2 files changed, 30 insertions(+), 11 deletions(-) diff --git a/Makefile b/Makefile index c4ed45837d..0115c4dfcc 100644 --- a/Makefile +++ b/Makefile @@ -573,8 +573,8 @@ prepare: $(BUILD_DIR)/buildroot-config/auto.conf .PHONY: world world: target-post-image -.PHONY: sdk -sdk: world +.PHONY: prepare-sdk +prepare-sdk: world @$(call MESSAGE,"Rendering the SDK relocatable") $(TOPDIR)/support/scripts/fix-rpath host $(TOPDIR)/support/scripts/fix-rpath staging @@ -582,6 +582,17 @@ sdk: world mkdir -p $(HOST_DIR)/share/buildroot echo $(HOST_DIR) > $(HOST_DIR)/share/buildroot/sdk-location +BR2_SDK_PREFIX ?= $(GNU_TARGET_NAME)_sdk-buildroot +.PHONY: sdk +sdk: prepare-sdk $(BR2_TAR_HOST_DEPENDENCY) + @$(call MESSAGE,"Generating SDK tarball") + $(if $(BR2_SDK_PREFIX),,$(error BR2_SDK_PREFIX can not be empty)) + $(Q)mkdir -p $(BINARIES_DIR) + $(TAR) czf "$(BINARIES_DIR)/$(BR2_SDK_PREFIX).tar.gz" \ + --owner=0 --group=0 --numeric-owner \ + --transform='s#^\.#$(BR2_SDK_PREFIX)#' \ + -C $(HOST_DIR) "." + # Populating the staging with the base directories is handled by the skeleton package $(STAGING_DIR): @mkdir -p $(STAGING_DIR) diff --git a/docs/manual/using-buildroot-toolchain.txt b/docs/manual/using-buildroot-toolchain.txt index 3246dc2411..0c0c35fced 100644 --- a/docs/manual/using-buildroot-toolchain.txt +++ b/docs/manual/using-buildroot-toolchain.txt @@ -12,15 +12,23 @@ The toolchain generated by Buildroot is located by default in +output/host/bin/+ to your PATH environment variable and then to use +ARCH-linux-gcc+, +ARCH-linux-objdump+, +ARCH-linux-ld+, etc. -It is possible to relocate the toolchain, this allows to distribute -the toolchain to other developers to build applications for your -target. To achieve this: +Alternatively, Buildroot can also export the toolchain and the development +files of all selected packages, as an SDK, by running the command ++make sdk+. This generates a tarball of the content of the host directory ++output/host/+, named +_sdk-buildroot.tar.gz+ (which can be +overriden by setting the environment variable +BR2_SDK_PREFIX+) and +located in the output directory +output/images/+. -* run +make sdk+, which prepares the toolchain to be relocatable; -* tarball the contents of the +output/host+ directory; -* distribute the resulting tarball. +This tarball can then be distributed to application developers, when +they want to develop their applications that are not (yet) packaged as +a Buildroot package. -Once the toolchain is installed to the new location, the user must run -the +relocate-sdk.sh+ script to make sure all paths are updated with -the new location. +Upon extracting the SDK tarball, the user must run the script ++relocate-sdk.sh+ (located at the top directory of the SDK), to make +sure all paths are updated with the new location. +Alternatively, if you just want to prepare the SDK without generating +the tarball (e.g. because you will just be moving the +host+ directory, +or will be generating the tarball on your own), Buildroot also allows +you to just prepare the SDK with +make prepare-sdk+ without actually +generating a tarball. -- 2.30.2