No description
The DEVICE_DEFINE() macro creates instances of struct device that are gathered into a contiguous list by the linker. However, some assemblers pad sections to the next 16-byte boundary or so by default, screwing up the list walk in z_sys_device_do_config_level(). This is especially true for 64-bit compilation where sizeof(struct device) isn't a multiple of 16. Enforcing an alignment at the linker level would solve this issue when instances of struct device are gathered from different object files. However it doesn't solve it when multiple instances are created within the same object file where the first instance still has a gap with the next instance, as the assembler does add padding upon section switch even though the object file ends up with a single section with both instances. In that case the linker would get rid of the trailing padding only, leaving the inner gaps between instances in place. The actual fix is to provide an explicit alignment attribute to the section for every instances, using __alignof(struct device) which is the alignment expected by the compiler for that structure. This also means that the x86_64 workaround in the struct device definition may go as the "edge case" it refers to is now properly handled. Signed-off-by: Nicolas Pitre <npitre@baylibre.com> |
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README.rst | ||
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version.h.in | ||
west.yml | ||
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.. raw:: html <a href="https://www.zephyrproject.org"> <p align="center"> <img src="doc/images/Zephyr-Project.png"> </p> </a> <a href="https://bestpractices.coreinfrastructure.org/projects/74"><img src="https://bestpractices.coreinfrastructure.org/projects/74/badge"></a> <img src="https://api.shippable.com/projects/58ffb2b8baa5e307002e1d79/badge?branch=master"> The Zephyr Project is a scalable real-time operating system (RTOS) supporting multiple hardware architectures, optimized for resource constrained devices, and built with security in mind. The Zephyr OS is based on a small-footprint kernel designed for use on resource-constrained systems: from simple embedded environmental sensors and LED wearables to sophisticated smart watches and IoT wireless gateways. The Zephyr kernel supports multiple architectures, including ARM Cortex-M, Intel x86, ARC, Nios II, Tensilica Xtensa, and RISC-V, and a large number of `supported boards`_. .. below included in doc/introduction/introduction.rst .. start_include_here Getting Started *************** Welcome to Zephyr! See the `Introduction to Zephyr`_ for a high-level overview, and the documentation's `Getting Started Guide`_ to start developing. Community Support ***************** Community support is provided via mailing lists and Slack; see the Resources below for details. Resources ********* Here's a quick summary of resources to help you find your way around: * **Help**: `Asking for Help Tips`_ * **Documentation**: http://docs.zephyrproject.org (`Getting Started Guide`_) * **Source Code**: https://github.com/zephyrproject-rtos/zephyr is the main repository; https://elixir.bootlin.com/zephyr/latest/source contains a searchable index * **Releases**: https://zephyrproject.org/developers/#downloads * **Samples and example code**: see `Sample and Demo Code Examples`_ * **Mailing Lists**: users@lists.zephyrproject.org and devel@lists.zephyrproject.org are the main user and developer mailing lists, respectively. You can join the developer's list and search its archives at `Zephyr Development mailing list`_. The other `Zephyr mailing list subgroups`_ have their own archives and sign-up pages. * **Nightly CI Build Status**: https://lists.zephyrproject.org/g/builds The builds@lists.zephyrproject.org mailing list archives the CI (shippable) nightly build results. * **Chat**: Zephyr's Slack workspace is https://zephyrproject.slack.com. Use this `Slack Invite`_ to register. * **Contributing**: see the `Contribution Guide`_ * **Wiki**: `Zephyr GitHub wiki`_ * **Issues**: https://github.com/zephyrproject-rtos/zephyr/issues * **Security Issues**: Email vulnerabilities@zephyrproject.org to report security issues; also see our `Security`_ documentation. Security issues are tracked separately at https://zephyrprojectsec.atlassian.net. * **Zephyr Project Website**: https://zephyrproject.org .. _Slack Invite: https://tinyurl.com/yarkuemx .. _supported boards: http://docs.zephyrproject.org/latest/boards .. _Zephyr Documentation: http://docs.zephyrproject.org .. _Introduction to Zephyr: http://docs.zephyrproject.org/latest/introduction/index.html .. _Getting Started Guide: http://docs.zephyrproject.org/latest/getting_started/index.html .. _Contribution Guide: http://docs.zephyrproject.org/latest/contribute/index.html .. _Zephyr GitHub wiki: https://github.com/zephyrproject-rtos/zephyr/wiki .. _Zephyr Development mailing list: https://lists.zephyrproject.org/g/devel .. _Zephyr mailing list subgroups: https://lists.zephyrproject.org/g/main/subgroups .. _Sample and Demo Code Examples: http://docs.zephyrproject.org/latest/samples/index.html .. _Security: http://docs.zephyrproject.org/latest/security/index.html .. _Asking for Help Tips: https://docs.zephyrproject.org/latest/guides/getting-help.html