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Unfortunately, another kernel patch is required for Genode/NOVA to get rid of global unique ids for objects (issue #268). Kernel patch: If a translate of a object capability item inside the same PD (receiver/sender in same PD) is not successful then he very same item is returned instead of the null item. Genode: Some code in Genode try to map/translate the "root" (the first instance of a) object capability within the same PD. The translate fails since it is the first cap and was not delegated beforehand. Instead the cap gets mapped to a new capability index due to xlt_rcv kernel item patch. The new local object capability index is used to lookup manged objects in lists, which however fails because the object is only known by the original object capability index. Unfortunately, this happens not only once. Below one example trace and description is attached. There are several possible solutions possible: * Find all places in Genode and replace normal function calls between objects with IPC calls, such that all capabilities can be translated during IPC. ** Time consuming to find all spots ** Rather platform specific issue requires re-adjustments in generic Genode code ** Not trivial to ever remember this fact during development of new components [other platforms have not such a issue, however have global object ids] ** Neither good in terms of performance. * Use some special system call to the kernel to be able to translate a given capability index as long until you find the requested original index. (Obviously ... no comment). * Kernel patch as this one. * <your proposal> Example trace + code description showing the behavior above: int main(): --- create local services --- int main(): --- start init --- [0] DEL OBJ PD:0xc000aa80->0xc000aa80 SB:0x000000aa RB:0x000000ac O:0x00 A:0x1f int main(): transferred 42 MB to init [0] DEL OBJ PD:0xc000aa80->0xc000aa80 SB:0x00000120 RB:0x0000013c O:0x00 A:0x1f [0] DEL OBJ PD:0xc000aa80->0xc000aa80 SB:0x0000016c RB:0x00000168 O:0x00 A:0x1f Setup ELF failed [0] XLT OBJ PD:0xc000aa80->0xc000aa80 SB:0x00000168 RB:0x0000016c O:0x00 unknown exception? int main(): --- init created, waiting for exit condition --- thread - file - line - text ------------------------------------------------------------------------------- thread A - [ 0] - 228 - new Core_child(... rom_session.dataspace() ...) thread A - [ 1] - 27 - IPC call - ask for dataspace cap thread B - [ 2] - 49 - function - return dataspace cap index 0x120 thread A - [ 1] - 27 - IPC returned - map 0x120 -> 0x13c, translate failed thread A - ... thread A - [ 3] - 231 - call _setup_elf() thread A - [ 3] - 60 - call env->rm_session()->attach() thread A - [ 4] - 35 - do dataspace object lookup (0x13c) thread A - [ 4] - 36 - lookup failed (object known as 0x120), throw Exception thread A - [ 3] - 61 - catch Exception -> return error code "0" thread A - [ 3] - 233 - "Setup ELF failed" - because error code "0" File legend: [0] base/src/core/main.cc [1] base/include/rom_session/client.h [2] base-nova/src/core/include/core_rm_session.h [3] base/src/base/process/process.cc [4] base-nova/src/core/core_rm_session.cc
=================================
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:
[http://genode.org/documentation/general-overview]
The current implementation can be compiled for 8 different kernels: Linux,
L4ka::Pistachio, L4/Fiasco, OKL4, NOVA, Fiasco.OC, Codezero, and a custom
kernel for the MicroBlaze architecture. 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.
Directory overview
##################
The Genode 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
:'base':
This directory contains the source-code repository of the fundamental
frameworks and interfaces of Genode. Furthermore, it contains the generic
parts of core.
:'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.
:'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)
:'pistachio':
L4ka::Pistachio kernel developed at University of Karlsruhe.
See [http://genode.org/community/wiki/GenodeOnL4kaPistachio]
:'fiasco':
L4/Fiasco kernel developed at University of Technology Dresden.
See [http://genode.org/community/wiki/GenodeOnL4Fiasco]
:'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 [http://genode.org/community/wiki/GenodeOnFiascoOC]
:'okl4':
OKL4 kernel (x86_32 and ARM) developed at Open-Kernel-Labs.
See [http://genode.org/community/wiki/GenodeOnOKL4]
:'nova':
NOVA hypervisor developed at University of Technology Dresden
See [http://genode.org/community/wiki/GenodeOnNOVA]
:'codezero':
Codezero microkernel developed by B-Labs
See [http://genode.org/community/wiki/GenodeOnCodezero]
:'mb':
Support for running Genode natively on the MicroBlaze softcore CPU.
See [http://genode.org/community/wiki/GenodeOnMicroBlaze]
:'host':
Pseudo platform documenting the interface between the generic and
platform-specific parts of the base framework. This is not a functional
base platform.
:'tool':
Source-code management tools and scripts. Please refer to the README file
contained in the directory.
:'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.
:'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.
:'linux_drivers':
Deprecated version of the Linux device driver environment featuring audio
drivers and the Intel GEM driver. This repository is in a transitionary
phase. Its functionality will be incorporated into 'dde_linux'.
:'dde_ipxe':
This source-code repository contains the device driver environment for
executing drivers of the iPXE project.
:'qt4':
This source-code repository contains the Genode version of Qt4 framework.
Please find more information about using Qt4 with Genode in the repository's
'README' file.
:'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.
:'ports-<platform>':
These platform-specific source-code repositories contain software that
capitalizes special features of the respective kernel platform. I.e.,
for the OKL4 base platform, a port of OKLinux is provided in 'ports-okl4'.
For the Fiasco.OC platform, 'ports-foc' hosts a port of the L4Linux
kernel. For further information, please refer to the README file at the
top level of the respective repository.
:'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'.
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:
[http://genode.org/community/mailing-lists]