This patch introduces the file-system-session interface, provides an
implementation of this interface in the form of an in-memory file
system, and enables the libc to use the new file-system facility.
The new interface resides in 'os/include/file_system_session/'. It
uses synchronous RPC calls for functions referring to directory
and meta-data handling. For transferring payload from/to files, the
packet-stream interface is used. I envision that the asynchronous design
of the packet-stream interface fits well will the block-session
interface. Compared to Unix-like file-system APIs, Genode's file-system
session interface is much simpler. In particular, it does not support
per-file permissions. On Genode, we facilitate binding policy (such as
write-permission) is sessions rather than individual file objects.
As a reference implementation of the new interface, there is the
new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse
files in memory. At the startup, 'ram_fs' is able to populate the
file-system content with directories and ROM modules as specified
in its configuration.
To enable libc-using programs to access the new file-system interface,
there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this
plugin, files stored on a native Genode file system can be accessed
using the traditional POSIX file API.
To see how the three parts described above fit together, the test
case at 'libports/run/libc_fs' can be taken as reference. It reuses
the original 'libc_ffat' test to exercise several file operations
on a RAM file-system using the libc API.
:Known limitations:
The current state should be regarded as work in progress. In particular
the error handling is not complete yet. Not all of the session functions
return the proper exceptions in the event of an error. I plan to
successively refine the interface while advancing the file-system
implementations. Also the support for truncating files and symlink
handling are not yet implemented.
Furthermore, there is much room for optimization, in particular for the
handling of directory entries. Currently, we communicate only one dir
entry at a time, which is bad when traversing large trees. However, I
decided to focus on functionality first and defer optimizations (such as
batching dir entries) to a later stage.
The current implementation does not handle file modification times at
all, which may be a severe limitation for tools that depend on this
information such as GNU make. Support for time will be added after we
have revisited Genode's timer-session interface (issue #1).
Fixes#54Fixes#171
This patch implements a Genode-specific audio backend for SDL.
The audio volume (in percent) can be configured in the config file of the
SDL application:
<config>
<sdl_audio_volume value="100"/>
</config>
Fixes#204.
This patch enables the use of threads and locking mechanisms in SDL
applications. The 'pthread' libary is used as backend. Not all features
are currently supported.
Fixes#185.
This patch provides an implementation of the '_nanosleep()' libc function,
which blocks on a timed semaphore for the given time, but at least 10ms.
This should result in better performance than creating a timer connection
on every call (for thread-safety), but could still be improved.
Fixes#158.
The 'log2()' and 'log2f()' functions have been added in FreeBSD's libc
version 9.0.0, but they are missing in version 8.2.0, which is used in
Genode. This patch provides preliminary implementations of these
functions until the Genode libc gets updated to version 9.0.0 or above.
Fixes#143.
This version of the library was hardwired to the former USB storage
driver supplied with DDE Linux. This driver is no more. The ffat.mk lib
is superseded by the libc_ffat plugin anyway. This plugin uses Genode's
block session interface instead of co-locating the block driver with the
application.
MuPDF is a fast and versatile PDF rendering library with only a few
dependencies. It depends on openjpeg (JPEG2000 codec) and jbig2dec (b/w
image compression library). Therefore, this patch comprises the ports of
these libraries as well. All libraries compile well in the Genode build
system but are not tested yet.
Removed dummy implementation of '_ioctl'. This function is called
internally within the libc, i.e., by 'tcgetattr'. For running
libreadline in Noux, we need to hook into those ioctl operations via
the libc plugin interface.
