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| -rw-r--r-- | README.md | 77 | ||||
| -rwxr-xr-x | loadDrivers.sh | 19 |
2 files changed, 65 insertions, 31 deletions
@@ -1,5 +1,4 @@ -Alsa Virtual Sound Driver --------------------------- +## Alsa Virtual Sound Driver The ALSA Virtual Sound Driver (AVIRT) aims to provide a Linux kernel solution to the issue of audio routing in kernel-space, as well as security per-stream, and dynamic configuration of streams at the kernel level. @@ -9,45 +8,99 @@ The top-level driver is configured (currently) using module parameters, as is th A sample dummy Audio Path is provided as an example to show how a low-level audio driver would subscribe to AVIRT, and accept audio routing for playback. +Currently, the Fiberdyne DSP hardmixer is supported on the Renesas R-Car M3 AGL +reference platform, and a default loopback softmixer is in development. + ## Building + ### Out Of Tree + The kernel modules can be built either in-tree, or out-of-tree. To build both AVIRT and the dummy Audio Path out-of-tree, use the following command: ```sh -$ CONFIG_AVIRT=m CONFIG_AVIRT_BUILDLOCAL=y CONFIG_AVIRT_DUMMYAP=m make -C /lib/modules/$(uname -r)/build/ M=$(pwd) +$ make all ``` -To build both AVIRT and the dummy Audio Path out-of-tree for [AGL](http://docs.automotivelinux.org/) (`aarch64` currently supported), use the [XDS](http://docs.automotivelinux.org/docs/devguides/en/dev/reference/xds/part-1/0_Abstract.html) build system together with the `make_agl.sh` script: +If building for [AGL](http://docs.automotivelinux.org/), use the [XDS](http://docs.automotivelinux.org/docs/devguides/en/dev/reference/xds/part-1/0_Abstract.html) build system together with the `make_agl.sh` script: ```sh $ ./make_agl.sh ${XDS_SDK_ID} ``` + ### In tree + To build in tree, use the [Fiberdyne Linux fork](https://github.com/fiberdyne/linux), which will automatically clone the AVIRT Driver and required AudioPath modules to the `drivers/staging` directory. You can then turn AVIRT Support on by setting to `<M>`. The drivers can be found here: + ``` $ make menuconfig # Navigate to: Device Drivers--->Staging Drivers--->AVIRT Support ``` + Finally build the kernel with the configuration selected by making. + ``` $ make ``` ## Running -To run, we must load the kernel modules using the `loadDrivers.sh` script, which contains sample module parameters to AVIRT: + +Firstly, install the resulting kernel modules to the appropriate modules +directory, and run`depmod`. For example, in AGL: + +```sh +cp avirt_core.ko avirt_dummyap.ko /lib/modules/4.14.0-yocto-standard/ +depmod +``` + +Now we can load the modules: + ```sh -$ ./loadDrivers.sh +modprobe avirt_core +modprobe avirt_dummyap ``` -To unload the drivers use: + +We must now configure AVIRT. We can do this with the test script: + +```sh +source scripts/test_configfs.sh +``` + +We can see the newly created streams by using the `aplay` utility. For example: + ```sh -$ ./unload.sh +aplay -l +... +card 2: avirt [avirt], device 0: multimedia [multimedia] + Subdevices: 1/1 + Subdevice #0: subdevice #0 +card 2: avirt [avirt], device 1: navigation [navigation] + Subdevices: 1/1 + Subdevice #0: subdevice #0 +card 2: avirt [avirt], device 2: emergency [emergency] + Subdevices: 1/1 + Subdevice #0: subdevice #0 ``` +## 4A Integration + +AVIRT has been integrated with [4a-softmixer](https://github.com/iotbzh/4a-softmixer) +and [4a-hal-generic](https://github.com/iotbzh/4a-hal-generic) to provide a smooth +transition from the existing aloop implementation to the future AVIRT loopback implementation. + +### User-space Library + +The user-space library [libavirt](https://github.com/fiberdyne/libavirt) can be used to configure AVIRT from within a given AGL 4A binding. + +### Hardmixer + +A new 4A mixer binding has been developed to demonstrate the capabilities of the +Fiberdyne DSP mixer operating on the HiFi2 core on-board the Renesas R-Car M3 M3ULCB +AGL reference platform. This is called the 'hardmixer', and is a faster, lower +latency alternative to the softmixer. + ## TODO - - Currently, playback only - implementing capture is WIP. - - Rework module parameters into configfs configuration. - - Create a loopback Audio Path for use with AVIRT, to demonstrate standard AGL soft-mixing capabilities. - - Modify Fiberdyne DSP driver for use with AVRIT, to demonstrate DSP off-loading and hard-mixing capabilities via Xtensa HiFi2. +- Currently, playback only - implementing capture is WIP. +- Create a loopback Audio Path for use with AVIRT, to demonstrate standard AGL soft-mixing capabilities. diff --git a/loadDrivers.sh b/loadDrivers.sh deleted file mode 100755 index 9ff5960..0000000 --- a/loadDrivers.sh +++ /dev/null @@ -1,19 +0,0 @@ -#!/bin/bash - -# Sample module parameters -params="\ -playback_num=4 \ -playback_chans=2,4,1,1 \ -playback_names=radio,media,nav,phone \ -capture_num=1 \ -capture_chans=2 \ -capture_names=voice" - -# Load the virtual driver -insmod avirt_core.ko "$params" - -# Load the additional audio path -#insmod dummy/avirt_dummyap.ko -insmod loopback/avirt_loopbackap.ko - -echo "Drivers Loaded!" |