genode/repos
Josef Söntgen 3d2b0cab93 libc: implement SNDCTL I/O control handling
In the same vein as the terminal and block I/O controls, the sound
controls are implemented via poperty files and match the OSS
API ([1] features a nice overview while [2] is v3 and [3] gives
in-depth information on the current v4.x API we eventually might want
to implement).

  [1] https://wiki.freebsd.org/RyanBeasley/ioctlref/
  [2] http://www.opensound.com/pguide/oss.pdf
  [3] http://manuals.opensound.com/developer/

The controls currently implemented are the ones used by the cmus OSS
output plugin, which was the driving factor behind the implementation.
It uses the obsolete (v3) API and does not check if the requested
parameter was actually set, which should be done according to the
official OSS documentation.

At the moment it is not possible to set or rather change any
parameters. In case the requested setting differs from the parameters
of the underlying Audio_out session - in contrast to the suggestion in
the OSS manual - we do not silently adjust the parameters returned
to the callee but outright fail the I/O control operation.

The following list contains all currently handled I/O controls.

  * SNDCTL_DSP_CHANNELS sets the number of channels. We return the
    available channels here and return ENOTSUP if it differs from
    the requested number of channels.

  * SNDCTL_DSP_GETOSPACE returns amount of playback data that can
    be written without blocking. For now it amounts the space left
    in the Audio_out packet-stream.

  * SNDCTL_DSP_POST forces playback to start. We do nothing and return
    success.

  * SNDCTL_DSP_RESET is supposed to reset the device when it is
    active before any parameters are changed. We do nothing and return
    success.

  * SNDCTL_DSP_SAMPLESIZE sets the sample size. We return the
    sample size of the underlying Audio_out session and return ENOTSUP
    if it differs from the requested number of channels.

  * SNDCTL_DSP_SETFRAGMENT sets the buffer size hint. We ignore the
    hint and return success.

  * SNDCTL_DSP_SPEED sets the samplerate. For now, we always return
    the rate of the underlying Audio_out session and return ENOTSUP
    if it differs from the requested one.

This commit serves as a starting point for further implementing the
OSS API by exploring more users, e.g. as VirtualBox/Qt5/SDL2 audio
backend or a more sophisticated progam like sndiod.

Issue #3891.
2020-10-09 13:44:14 +02:00
..
base test/entrypoint: extend timeout interval 2020-10-09 13:37:14 +02:00
base-fiasco depot: update recipe hashes 2020-10-09 13:35:57 +02:00
base-foc depot: update recipe hashes 2020-10-09 13:35:57 +02:00
base-hw depot: update recipe hashes 2020-10-09 13:35:57 +02:00
base-linux depot: update recipe hashes 2020-10-09 13:35:57 +02:00
base-nova depot: update recipe hashes 2020-10-09 13:35:57 +02:00
base-okl4 depot: update recipe hashes 2020-10-09 13:35:57 +02:00
base-pistachio depot: update recipe hashes 2020-10-09 13:35:57 +02:00
base-sel4 depot: update recipe hashes 2020-10-09 13:35:57 +02:00
dde_bsd depot: update recipe hashes 2020-10-09 13:35:57 +02:00
dde_ipxe depot: update recipe hashes 2020-10-09 13:35:57 +02:00
dde_linux depot: update recipe hashes 2020-10-09 13:35:57 +02:00
dde_rump depot: update recipe hashes 2020-10-09 13:35:57 +02:00
demo depot: update recipe hashes 2020-10-09 13:35:57 +02:00
gems depot: update recipe hashes 2020-10-09 13:35:57 +02:00
hello_tutorial Add missing override annotations 2019-02-19 11:12:11 +01:00
libports libc: implement SNDCTL I/O control handling 2020-10-09 13:44:14 +02:00
os Ensure high priority for timer in test.run 2020-10-09 13:37:17 +02:00
ports depot: update recipe hashes 2020-10-09 13:35:57 +02:00
README Remove dde_zircon 2020-08-25 11:49:44 +02:00

                      ===============================
                      Genode source-code repositories
                      ===============================


This directory contains the source-code repositories of the Genode OS
Framework. Each sub directory has the same principle layout as described in the
build-system manual:

:Build-system manual:

  [https://genode.org/documentation/developer-resources/build_system]

The build system uses a configurable selection of those reposities to obtain
the source codes for the build process. The repositories are not independent
but build upon of each other:

:'base':

  This directory contains the source-code repository of the fundamental
  frameworks and interfaces of Genode. Furthermore, it contains the generic
  parts of core.

:'base-<platform>':
  These directories contain platform-specific source-code repositories
  complementing the 'base' repository. The following platforms are supported:

  :'linux':
    Linux kernel (both x86_32 and x86_64)

  :'nova':
    NOVA hypervisor developed at University of Technology Dresden
    See [https://genode.org/documentation/platforms/nova]

  :'foc':
    Fiasco.OC is a modernized version of the Fiasco microkernel with a
    completely revised kernel interface fostering capability-based
    security. It is not compatible with L4/Fiasco.
    See [https://genode.org/documentation/platforms/foc]

  :'hw':
    The hw platform allows the execution of Genode on bare ARM and x86 hardware
    without the need for a separate kernel. The kernel functionality is
    included in core except in the special case of the Muen separation
    kernel.
    See [https://genode.org/documentation/platforms/hw] and
    [https://genode.org/documentation/platforms/muen]

  :'okl4':
    OKL4 kernel (x86_32 and ARM) developed at Open-Kernel-Labs.
    See [https://genode.org/documentation/platforms/okl4]

  :'pistachio':
    L4ka::Pistachio kernel developed at University of Karlsruhe.
    See [https://genode.org/documentation/platforms/pistachio]

  :'fiasco':
    L4/Fiasco kernel developed at University of Technology Dresden.
    See [https://genode.org/documentation/platforms/fiasco]

  :'sel4':
    seL4 microkernel developed at NICTA/General Dynamics
    See[https://sel4.systems/]

:'os':

  This directory contains the non-base OS components such as the init process,
  device drivers, and basic system services.

:'demo':

  This directory contains the source-code repository of various services and
  applications that we use for demonstration purposes. For example, a graphical
  application launcher called Launchpad and the Scout tutorial browser.

:'hello_tutorial':

  Tutorial for creating a simple client-server scenario with Genode. This
  repository includes documentation and the complete source code.

:'libports':

  This source-code repository contains ports of popular open-source libraries
  to Genode, most importantly the C library. The repository contains no
  upstream source code but means to download the code and adapt it to Genode.
  For instructions about how to use this mechanism, please consult the README
  file at the top level of the repository. Among the 3rd-party libraries
  are Qt5, libSDL, freetype, Python, ncurses, Mesa, and libav.

:'dde_linux':

  This source-code repository contains the device driver environment for
  executing Linux device drivers natively on Genode. Currently, this
  repository hosts the USB stack.

:'dde_ipxe':

  This source-code repository contains the device-driver environment for
  executing drivers of the iPXE project.

:'dde_bsd':

  This source-code repository contains the device-driver environment for
  drivers of the OpenBSD operating system.

:'dde_rump':

  This source-code repository contains the port of rump kernels, which are
  used to execute subsystems of the NetBSD kernel as user level processes.
  The repository contains a server that uses a rump kernel to provide
  various NetBSD file systems to Genode.

:'ports':

  This source-code repository hosts ports of 3rd-party applications to
  Genode. The repository does not contain upstream source code but provides
  a mechanism for downloading the official source distributions and adapt
  them to the Genode environment. The used mechanism is roughly the same
  as used for the 'libports' repository. Please consult 'libports/README'
  for further information.

:'gems':

  This source-code repository contains Genode applications that use
  both native Genode interfaces as well as features of other high-level
  repositories, in particular shared libraries provided by 'libports'.