From: Eric Anholt Date: Fri, 16 Oct 2020 22:50:40 +0000 (-0700) Subject: docs: Document how to build and install Android drivers. X-Git-Tag: upstream/21.0.0~3534 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0f82c99c4e62d999efaa4d9355c151d00d1931ac;p=platform%2Fupstream%2Fmesa.git docs: Document how to build and install Android drivers. This is what I've been using so far. Reviewed-by: Kristian H. Kristensen Part-of: --- diff --git a/docs/android.rst b/docs/android.rst new file mode 100644 index 0000000..1d41d32 --- /dev/null +++ b/docs/android.rst @@ -0,0 +1,167 @@ +Android +======= + +Mesa hardware drivers can be built for Android one of two ways: built +into the Android OS using the Android.mk build sytem on older versions +of Android, or out-of-tree using the Meson build system and the +Android NDK. + +The Android.mk build system has proven to be hard to maintain, as one +needs a built Android tree to build against, and it has never been +tested in CI. The meson build system flow is frequently used by +Chrome OS developers for building and testing Android drivers. + +Building using the Android NDK +------------------------------ + +Download and install the NDK using whatever method you normally would. +Then, create your meson cross file to use it, something like this +``~/.local/share/meson/cross/android-aarch64`` file:: + + [binaries] + ar = 'NDKDIR/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android-ar' + c = ['ccache', 'NDKDIR/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android29-clang', '-fuse-ld=lld'] + cpp = ['ccache', 'NDKDIR/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android29-clang++', '-fuse-ld=lld', '-fno-exceptions', '-fno-unwind-tables', '-fno-asynchronous-unwind-tables', '-static-libstdc++'] + strip = 'NDKDIR/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android-strip' + # Android doesn't come with a pkg-config, but we need one for meson to be happy not + # finding all the optional deps it looks for. Use system pkg-config pointing at a + # directory we get to populate with any .pc files we want to add for Android + pkgconfig = ['env', 'PKG_CONFIG_LIBDIR=NDKDIR/pkgconfig', '/usr/bin/pkg-config'] + + [host_machine] + system = 'linux' + cpu_family = 'arm' + cpu = 'armv8' + endian = 'little' + +Now, use that cross file for your Android build directory (as in this +one cross-compiling the turnip driver for a stock Pixel phone) + +.. code-block:: console + + meson build-android-aarch64 \ + --cross-file android-aarch64 \ + -Dplatforms=android \ + -Dplatform-sdk-version=26 \ + -Dandroid-stub=true \ + -Dgallium-drivers= \ + -Dvulkan-drivers=freedreno \ + -Dfreedreno-kgsl=true + ninja -C build-android-aarch64 + +Replacing Android drivers on stock Android +------------------------------------------ + +The vendor partition with the drivers is normally mounted from a +read-only disk image on ``/vendor``. To be able to replace them for +driver development, we need to unlock the device and remount +``/vendor`` read/write. + +.. code-block:: console + + adb disable-verity + adb reboot + adb remount -R + +Now you can replace drivers as in: + +.. code-block:: console + + adb push build-android-aarch64/src/freedreno/vulkan/libvulkan_freedreno.so /vendor/lib64/hw/vulkan.sdm710.so + +Note this command doesn't quite work because libvulkan wants the +SONAME to match. For now, in turnip we have been using a hack to the +meson.build to change the SONAME. + +Replacing Android drivers on Chrome OS +-------------------------------------- + +Chrome OS's ARC++ is an Android container with hardware drivers inside +of it. The vendor partition with the drivers is normally mounted from +a read-only squashfs image on disk. For doing rapid driver +development, you don't want to regenerate that image. So, we'll take +the existing squashfs image, copy it out on the host, and then use a +bind mount instead of a loopback mount so we can update our drivers +using scp from outside the container. + +On your device, you'll want to make ``/`` read-write. ssh in as root +and run: + +.. code-block:: console + + crossystem dev_boot_signed_only=0 + /usr/share/vboot/bin/make_dev_ssd.sh --remove_rootfs_verification --partitions 4 + reboot + +Then, we'll switch Android from using an image for ``/vendor`` to using a +bind-mount from a directory we control. + +.. code-block:: console + + cd /opt/google/containers/android/ + mkdir vendor-ro + mount -o loop vendor.raw.img vendor-ro + cp -a vendor-ro vendor-rw + emacs config.json + +In the ``config.json``, you want to find the block for ``/vendor`` and +change it to:: + + { + "destination": "/vendor", + "type": "bind", + "source": "/opt/google/containers/android/vendor-rw", + "options": [ + "bind", + "rw" + ] + }, + +Now, restart the UI to do a full reload: + +.. code-block:: console + + restart ui + +At this point, your android container is restarted with your new +bind-mount ``/vendor``, and if you use ``android-sh`` to shell into it +then the ``mount`` command should show:: + + /dev/root on /vendor type ext2 (rw,seclabel,relatime) + +Now, replacing your DRI driver with a new one built for Android should +be a matter of: + +.. code-block:: console + + scp msm_dri.so $HOST:/opt/google/containers/android/vendor-rw/lib64/dri/ + +You can do your build of your DRI driver using ``emerge-$BOARD +arc-mesa-freedreno`` (for example) if you have a source tree with +ARC++, but it should also be possible to build using the NDK as +described above. There are currently rough edges with this, for +example the build will require that you have your arc-libdrm build +available to the NDK, assuming you're building anything but the +freedreno vulkan driver for KGSL. You can mostly put things in place +with: + +.. code-block:: console + + scp $HOST:/opt/google/containers/android/vendor-rw/lib64/libdrm.so \ + NDKDIR/sysroot/usr/lib/aarch64-linux-android/lib/ + + ln -s \ + /usr/include/xf86drm.h \ + /usr/include/libsync.h \ + /usr/include/libdrm \ + NDKDIR/sysroot/usr/include/ + +It seems that new invocations of an application will often reload the +DRI driver, but depending on the component you're working on you may +find you need to reload the whole Android container. To do so without +having to log in to Chrome again every time, you can just kill the +container and let it restart: + +.. code-block:: console + + kill $(cat /run/containers/android-run_oci/container.pid ) diff --git a/docs/contents.rst b/docs/contents.rst index 4e2e458..f7fd50d 100644 --- a/docs/contents.rst +++ b/docs/contents.rst @@ -64,6 +64,7 @@ sourcedocs dispatch gallium/index + android .. toctree:: :maxdepth: 1