Norman Feske 1f4f119b1e Capability quota accounting and trading
This patch mirrors the accounting and trading scheme that Genode employs
for physical memory to the accounting of capability allocations.

Capability quotas must now be explicitly assigned to subsystems by
specifying a 'caps=<amount>' attribute to init's start nodes.
Analogously to RAM quotas, cap quotas can be traded between clients and
servers as part of the session protocol. The capability budget of each
component is maintained by the component's corresponding PD session at
core.

At the current stage, the accounting is applied to RPC capabilities,
signal-context capabilities, and dataspace capabilities. Capabilities
that are dynamically allocated via core's CPU and TRACE service are not
yet covered. Also, the capabilities allocated by resource multiplexers
outside of core (like nitpicker) must be accounted by the respective
servers, which is not covered yet.

If a component runs out of capabilities, core's PD service prints a
warning to the log. To observe the consumption of capabilities per
component in detail, the PD service is equipped with a diagnostic
mode, which can be enabled via the 'diag' attribute in the target
node of init's routing rules. E.g., the following route enables the
diagnostic mode for the PD session of the "timer" component:

  <default-route>
    <service name="PD" unscoped_label="timer">
      <parent diag="yes"/>
    </service>
    ...
  </default-route>

For subsystems based on a sub-init instance, init can be configured
to report the capability-quota information of its subsystems by
adding the attribute 'child_caps="yes"' to init's '<report>'
config node. Init's own capability quota can be reported by adding
the attribute 'init_caps="yes"'.

Fixes #2398
2017-05-31 13:16:06 +02:00
2017-03-15 12:24:41 +01:00
2017-05-31 13:16:00 +02:00
2017-02-28 12:59:28 +01:00
2016-08-30 17:24:00 +02:00
2017-02-28 14:19:27 +01:00

                      =================================
                      Genode Operating System Framework
                      =================================


This is the source tree of the reference implementation of the Genode OS
architecture. For a general overview about the architecture, please refer to
the project's official website:

:Official project website for the Genode OS Framework:

  [https://genode.org/documentation/general-overview]

The current implementation can be compiled for 8 different kernels: Linux,
L4ka::Pistachio, L4/Fiasco, OKL4, NOVA, Fiasco.OC, seL4, and a custom
kernel for running Genode directly on ARM-based hardware. Whereas the Linux
version serves us as development vehicle and enables us to rapidly develop the
generic parts of the system, the actual target platforms of the framework are
microkernels. There is no "perfect" microkernel - and neither should there be
one. If a microkernel pretended to be fit for all use cases, it wouldn't be
"micro". Hence, all microkernels differ in terms of their respective features,
complexity, and supported hardware architectures.

Genode allows the use of each of the kernels listed above with a rich set of
device drivers, protocol stacks, libraries, and applications in a uniform way.
For developers, the framework provides an easy way to target multiple different
kernels instead of tying the development to a particular kernel technology. For
kernel developers, Genode contributes advanced workloads, stress-testing their
kernel, and enabling a variety of application use cases that would not be
possible otherwise. For users and system integrators, it enables the choice of
the kernel that fits best with the requirements at hand for the particular
usage scenario.


Documentation
#############

The primary documentation is the book "Genode Foundations", which is available
on the front page of Genode website:

:Download the book "Genode Foundations":

  [https://genode.org]

The book describes Genode in a holistic and comprehensive way. It equips you
with a thorough understanding of the architecture, assists developers with the
explanation of the development environment and system configuration, and
provides a look under the hood of the framework. Furthermore, it contains the
specification of the framework's programming interface.

The project has a quarterly release cycle. Each version is accompanied with
detailed release documentation, which is available at the documentation
section of the project website:

:Release documentation:

  [https://genode.org/documentation/release-notes/]


Directory overview
##################

The source tree is composed of the following subdirectories:

:'doc':

  This directory contains general documentation. Please consider the following
  document for a quick guide to get started with the framework:

  ! doc/getting_started.txt

  If you are curious about the ready-to-use components that come with the
  framework, please review the components overview:

  ! doc/components.txt

:'repos':

  This directory contains the so-called source-code repositories of Genode.
  Please refer to the README file in the 'repos' directory to learn more
  about the roles of the individual repositories.

:'tool':

  Source-code management tools and scripts. Please refer to the README file
  contained in the directory.


Additional community-maintained components
##########################################

The components found within the main source tree are complemented by a growing
library of additional software, which can be seamlessly integrated into Genode
system scenarios.

:Genode-world repository:

  [https://github.com/genodelabs/genode-world]


Contact
#######

The best way to get in touch with Genode developers and users is the project's
mailing list. Please feel welcome to join in!

:Genode Mailing Lists:

  [https://genode.org/community/mailing-lists]


Commercial support
##################

The driving force behind the Genode OS Framework is the German company Genode
Labs. The company offers commercial licensing, trainings, support, and
contracted development work:

:Genode Labs website:

  [https://www.genode-labs.com]

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