The engine reads one frame from as many descriptors as it has buffers, the preheader riding on the first and every descriptor but the last carrying the more bit. Describing a fragmented skb that way removes the copy that linearising it costs, so the conduit advertises NETIF_F_SG. The engine returns one completion per descriptor rather than one per frame: the opaque that names the frame is written only for the descriptor that carried the preheader, and every completion but the last sets a more bit of its own. The frame is therefore named by the first completion of its run and released on the one that clears that bit, and an opaque outside the ring names no frame and is refused rather than indexed with. A frame holds a store slot per descriptor it was written from, and a slot is released only once its descriptor has been read, so that a transmit taking the slot cannot place a frame over what the release still has to unmap. Teardown releases a frame from the descriptor that carried its preheader, so the walk over the ring on free reaches every frame the ring holds, and the separate drain of the descriptors the engine has not read is removed. A frame of more than 32 buffers, or one whose buffers fall below 16 bytes before the last, is linearised instead. The queue stops with room for a frame that takes every descriptor, or it would restart on space the next frame could not use. Assisted-by: Claude:claude-opus-5 Signed-off-by: Julius Bairaktaris <julius@bairaktaris.de> Link: https://github.com/openwrt/openwrt/pull/25117 Signed-off-by: Robert Marko <robimarko@gmail.com>
OpenWrt Project is a Linux operating system targeting embedded devices. Instead of trying to create a single, static firmware, OpenWrt provides a fully writable filesystem with package management. This frees you from the application selection and configuration provided by the vendor and allows you to customize the device through the use of packages to suit any application. For developers, OpenWrt is the framework to build an application without having to build a complete firmware around it; for users this means the ability for full customization, to use the device in ways never envisioned.
Sunshine!
Download
Built firmware images are available for many architectures and come with a package selection to be used as WiFi home router. To quickly find a factory image usable to migrate from a vendor stock firmware to OpenWrt, try the Firmware Selector.
If your device is supported, please follow the Info link to see install instructions or consult the support resources listed below.
An advanced user may require additional or specific package. (Toolchain, SDK, ...) For everything else than simple firmware download, try the wiki download page:
Development
To build your own firmware you need a GNU/Linux, BSD or macOS system (case sensitive filesystem required). Cygwin is unsupported because of the lack of a case sensitive file system.
Requirements
You need the following tools to compile OpenWrt, the package names vary between distributions. A complete list with distribution specific packages is found in the Build System Setup documentation.
binutils bzip2 diff find flex gawk gcc-6+ getopt grep install libc-dev libz-dev
make4.1+ perl python3.8+ rsync subversion unzip which
Quickstart
-
Run
./scripts/feeds update -ato obtain all the latest package definitions defined in feeds.conf / feeds.conf.default -
Run
./scripts/feeds install -ato install symlinks for all obtained packages into package/feeds/ -
Run
make menuconfigto select your preferred configuration for the toolchain, target system & firmware packages. -
Run
maketo build your firmware. This will download all sources, build the cross-compile toolchain and then cross-compile the GNU/Linux kernel & all chosen applications for your target system.
Related Repositories
The main repository uses multiple sub-repositories to manage packages of
different categories. All packages are installed via the OpenWrt package
manager called opkg. If you're looking to develop the web interface or port
packages to OpenWrt, please find the fitting repository below.
-
LuCI Web Interface: Modern and modular interface to control the device via a web browser.
-
OpenWrt Packages: Community repository of ported packages.
-
OpenWrt Routing: Packages specifically focused on (mesh) routing.
-
OpenWrt Video: Packages specifically focused on display servers and clients (Xorg and Wayland).
Support Information
For a list of supported devices see the OpenWrt Hardware Database
Documentation
Support Community
- Forum: For usage, projects, discussions and hardware advise.
- Support Chat: Channel
#openwrton oftc.net.
Developer Community
- Bug Reports: Report bugs in OpenWrt
- Dev Mailing List: Send patches
- Dev Chat: Channel
#openwrt-develon oftc.net.
License
OpenWrt is licensed under GPL-2.0
