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Diffstat (limited to 'README.md')
| -rw-r--r-- | README.md | 46 |
1 files changed, 32 insertions, 14 deletions
@@ -138,13 +138,6 @@ to change the `uid` value in `metadata` section and `path` values in `playbacks` All these values should be replaced by the alsa entry path of your usb device, these entry are listed under directory '/dev/snd/by-id/...'. -### Selection of the hal loaded at binding launch - -Currently, the 4a-hal binding will try to launch a hal for each json audio configuration -files found in path specified with CONTROL_CONFIG_PATH (an audio configuration file should begin with 4a-hal-*). -If you don't want a hal to be launch with the binding, you can just rename/remove the corresponding -audio json configuration file. - ## Compile (for each repositories) ```bash @@ -156,6 +149,16 @@ make ## Using '4a-hal' binder +### Selection of the hal loaded at binding launch + +Currently, the 4a-hal binding will try to launch a hal for each json audio configuration +files found in path specified with CONTROL_CONFIG_PATH (an audio configuration file should begin with 4a-hal-*). +If you don't want a hal to be launch with the binding, you can just rename/remove the corresponding +audio json configuration file. + +Be aware that every hal which will find its associated audio device will attach to the mixer. +So, if you work on M3 and want to use an external usb audio device, be sure to rename the m3 configuration file. + ### Run your binder from shell ```bash @@ -232,13 +235,14 @@ To load an external to '4a-hal-manger', you need to you use an 'api_call' from y With this 'api_call' you must sent a json description of your api: ```json -{ - "api" : mandatory, string that is your hal binding api - "uid" : mandatory, string that specify your hal uid (usually the device used by your hal) - "info" : optional, string that describes your hal - "author" : optional, string that says who is the author of your hal - "version" : optional, string that says what is the version of your hal - "date" : optional, string that says the date of your hal +"metadata" : { + "api" : "mandatory, string that is your hal binding api", + "uid" : "mandatory, string that specify your hal uid (usually the device used by your hal)", + "info" : "optional, string that describes your hal", + "author" : "optional, string that says who is the author of your hal", + "version" : "optional, string that says what is the version of your hal", + "date" : "optional, string that says the date of your hal", + "snd-dev-id": "optional, integer that specify you alsa device id (hw:X), -1 if not available" } ``` @@ -247,6 +251,20 @@ Your hal must also have a 'subscribe' verb available and event name 'hal_status' At external hal loading, the '4a-hal-manager' will subscribe to this event. Within your hal, you must generate an event each time the status of your hal changes. +### Known issues + +#### Fail to find json configuration files + +When compiling and executing 4a-hal-generic and 4a-softmixer for a specific target using an sdk, +some bindings won't find there json configuration files. +This issue does not appears when compiling and deploying the 4a-hal-generic/4a-softmixer +with yocto because a recipe its taking charge of these issues. + +Nevertheless, to make the bindings find their configuration files, you can export the `CONTROL_CONFIG_PATH` +environment variable to the directories where the configuration files are stored. +Example on a target where the 4a-hal and 4a-softmixer are deployed into `/home/root/4a` directory : +`export CONTROL_CONFIG_PATH=/home/root/4a/smixer/etc:/home/root/4a/4a-hal/etc`. + ## What is missing in this version * Check that external hal really exist at loading |