diff --git a/docs/dev/hardware.rst b/docs/dev/hardware.rst new file mode 100644 index 00000000..751c94e0 --- /dev/null +++ b/docs/dev/hardware.rst @@ -0,0 +1,102 @@ +Adding support for new hardware +=============================== +This page will give a short overview on how to add support +for new hardware to Gluon. + +Hardware requirements +--------------------- +Having an ath9k (or ath10k) based WLAN adapter is highly recommended, +although other chipsets may also work. VAP (multiple SSID) support +is a requirement. At the moment, Gluon's scripts can't handle devices +without WLAN adapters (although such environments may also be interesting, +e.g. for automated testing in virtual machines). + +.. _hardware-adding-profiles: + +Adding profiles +--------------- +The vast majority of devices with ath9k WLAN uses the ar71xx target of OpenWrt. +If the hardware you want to add support for is also ar71xx, adding a new profile +is enough. + +Profiles are defined in ``targets/-/profiles.mk``. There are two macros +used to define which images are generated: ``GluonProfile`` and ``GluonModel``. The following examples +are taken from ``profiles.mk`` of the ``ar71xx-generic`` target:: + + $(eval $(call GluonProfile,TLWR1043)) + $(eval $(call GluonModel,TLWR1043,tl-wr1043nd-v1-squashfs,tp-link-tl-wr1043n-nd-v1)) + $(eval $(call GluonModel,TLWR1043,tl-wr1043nd-v2-squashfs,tp-link-tl-wr1043n-nd-v2)) + +The ``GluonProfile`` macro takes at least one parameter, the profile name as it is +defined in the Makefiles of OpenWrt (``openwrt/target/linux///profiles/*`` +and ``openwrt/target/linux//image/Makefile``). If the target you are on doesn't define +profiles (e.g. on x86), just add a single profile called ``Generic`` or similar. + +It may optionally take a second parameter which defines additional packages to include for the profile +(e.g. ath10k). The additional packages defined in ``openwrt/target/linux///profiles/*`` +aren't used. + +The ``GluonModel`` macro takes three parameters: The profile name, the suffix of the image file +generated by OpenWrt (without the file extension), and the final image name of the Gluon image. +The final image name must be the same that is returned by the following command. + +:: + + lua -e 'print(require("platform_info").get_image_name())' + + +This is so the autoupdater can work. On targets with aren't supported by the autoupdater, +``require("platform_info").get_image_name()`` will just return ``nil`` and the final image name +may be defined arbitrarily. + +On devices with multiple WLAN adapters, care must also be taken that the primary MAC address is +configured correctly. ``/lib/gluon/core/sysconfig/primary_mac`` should contain the MAC address which +can be found on a label on most hardware; if it does not, ``/lib/gluon/upgrade/core/initial/001-sysconfig`` +in ``gluon-core`` might need a fix. (There have also been cases in which the address was incorrect +even on devices with only one WLAN adapter, in these cases an OpenWrt bug was the cause). + +Adding support for new hardware targets +--------------------------------------- +Adding a new target is much more complex than adding a new profile. There are two basic steps +required for adding a new target: + +Adjust packages +''''''''''''''' +One package that definitely needs adjustments for every new target added is ``lua-platform-info``. Just +start with a copy of an existing platform info script, adjust it for the new target, and add the new target +to the list of supported targets in the package Makefile. + +On many targets, Gluon's network setup scripts (mainly in the packages ``gluon-core`` and ``gluon-mesh-batman-adv-core``) +won't run correctly without some adjustments, so better double check that everything is fine there (and the files +``primary_mac``, ``lan_ifname`` and ``wan_ifname`` in ``/lib/gluon/core/sysconfig/`` contain sensible values). + +Add support to the build system +''''''''''''''''''''''''''''''' +A directory for the new target must be created under ``targets``, and it must be added +to ``targets/targets.mk``. In the new target directory, four files must be created: + +* config +* kernel-config +* kernel-vermagic +* profiles.mk + +The file ``config`` can be used to add additional, target-specific options to the OpenWrt config. If such options +aren't necessary, it can be left empty. For ``profiles.mk``, see :ref:`hardware-adding-profiles`. + +The files ``kernel-config`` and ``kernel-vermagic`` must have the correct content so kernel modules from the upstream repositories +can be easily installed. The OpenWrt version a Gluon release is based on is defined by the upstream package repo URL in ``include/gluon.mk`` +(in the variable ``CONFIG_VERSION_REPO``); at the time this documentation was written, this was ``barrier_breaker/14.07-rc3``; whenever +the package repo is updated, all ``kernel-config`` and ``kernel-vermagic`` files must be updated as well. + +The file ``kernel-vermagic`` just contains a hash which is part of the version number of the kernel package. So in the case of ``ar71xx-generic`` on +``barrier_breaker/14.07-rc3``, we look in the directory ``https://downloads.openwrt.org/barrier_breaker/14.07-rc3/ar71xx/generic/packages/`` and +find that the kernel package is called ``kernel_3.10.49-1-94831e5bcf361d1c03e87a15e152b0e8_ar71xx.ipk``. This makes the ``kernel-vermagic`` the +string ``94831e5bcf361d1c03e87a15e152b0e8``. + +For ``kernel-config``, the OpenWrt image builder must be downloaded. Again, for ``ar71xx-generic`` on +``barrier_breaker/14.07-rc3``, we download ``OpenWrt-SDK-ar71xx-for-linux-x86_64-gcc-4.8-linaro_uClibc-0.9.33.2.tar.bz2`` +from ``https://downloads.openwrt.org/barrier_breaker/14.07-rc3/ar71xx/generic/``. After unpacking it, we use the file +``OpenWrt-ImageBuilder-ar71xx_generic-for-linux-x86_64/build_dir/target-mips_34kc_uClibc-0.9.33.2/linux-ar71xx_generic/linux-3.10.49/.config`` +as our ``kernel-config``. + +After this, is should be sufficient to call ``make GLUON_TARGET=-`` to build the images for the new target. diff --git a/docs/index.rst b/docs/index.rst index 53e1a97a..1e616a1b 100644 --- a/docs/index.rst +++ b/docs/index.rst @@ -34,6 +34,7 @@ Developer Documentation :maxdepth: 2 dev/basics + dev/hardware Supported Devices -----------------