genode

History

Norman Feske bbe3ee8dc5 block_session: server-defined payload alignment This patch replaces the formerly fixed 2 KiB data alignment within the packet-stream buffer by a server-defined alignment. This has two benefits. First, when using block servers that provide small block sizes like 512 bytes, we avoid fragmenting the packet-stream buffer, which occurs when aligning 512-byte requests at 2 KiB boundaries. This reduces meta data costs for the packet-stream allocator and also allows fitting more requests into the buffer. Second, block drivers with alignment constraints dictated by the hardware can now pass those constraints to the client, thereby easing the use of zero-copy DMA directly into the packet stream. The alignment is determined by the Block::Session_client at construction time and applied by the Block::Session_client::alloc_packet method. Block-session clients should always use this method, not the 'alloc_packet' method of the packet stream (tx source) directly. The latter merely applies a default alignment of 2 KiB. At the server side, the alignment is automatically checked by block/component.h (old API) and block/request_stream.h (new API). Issue #3274		2019-05-03 13:53:12 +02:00
..
doc	tool: remove deprecated 'make prepare' mechanism	2016-03-17 17:02:04 +01:00
include	qt5: remove deprecated APIs	2019-02-26 14:38:03 +01:00
lib	spark: provide rcheck symbols in ABI	2019-04-09 12:30:35 +02:00
ports	Use https URLs for qt5 downloads	2019-03-18 15:56:23 +01:00
recipes	depot: update recipe hashes	2019-04-09 12:30:35 +02:00
run	extract: discharge dependency from timer session	2019-04-09 12:30:35 +02:00
src	block_session: server-defined payload alignment	2019-05-03 13:53:12 +02:00
README	README update	2016-08-30 17:24:00 +02:00

README

This directory contains ports of popular 3rd-party software to Genode.


Usage
-----

The tool './tool/ports/prepare_port' in the toplevel directory automates the
task of downloading and preparing the library source codes. You can select
individual packages that have to be prepared by specifying their base names
(without the version number) as command-line argument. For example, the
following command prepares both the C library and the Freetype library:
! ./tool/ports/prepare_port libc freetype

To compile and link against 3rd-party libraries of the 'libports' repository,
you have to include the repository into the build process by appending it to the
'REPOSITORIES' declaration of your '<build-dir>/etc/build.conf' file.


Under the hood
--------------

For each library, there is a file contained in the 'libports/ports/'
subdirectory. The file is named after the library and contains the
library-specific rules for downloading the source code and installing header
files.


How does 'libports' relate to the other repositories?
-----------------------------------------------------

Most libraries hosted in the 'libports' repository expect a complete C library,
which is provided with the 'libc' package. Please do not forget to prepare the
libc package when using any of the other libports packages. The libc, in turn,
depends on the 'os' repository for its back end. Because the 'os' repository is
the home of the dynamic linker, libraries contained in 'libports' are safe to
assume the presence of the dynamic linker and, thus, should be built as shared
libraries.