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
The 'Session_policy' helper could not cope well with configurations that
contain nodes of a type other than '<policy>'. This patch improves the
policy matching by skipping non-policy nodes.
Due to recent changes on the Fiasco.OC platform, when building ldso
applications for this platform the std::terminate function is needed
by the ~Ipc_server destructor. So we've to add it to ldso's whitelist.
This patch increases the stack size of entrypoint threads in the PCI and
PS/2 drivers, in the Terminal server and in the Signal service for 64-bit
Genode/Fiasco.OC built with -O0.
Fixes#198.
The original loader service was primarily motivated by the
browser-plugin scenario presented on our live CD. The new version
implements a more general session interface, which widens the
application scope of the service and, at the same time, reduces its
implementation complexity.
The complexity reduction is achieved by removing the original limitation
of supplying the new sub system as a single binary blob only. The server
used to implement heuristics and functionality for dealing with
different kinds of blobs such as ELF images or TAR archives. This has
been replaced by a session-local ROM service, which can be equipped with
an arbitrary number of ROM modules supplied by the loader client prior
starting the new sub system. Even though the TAR support has been
removed, a separate instance of the 'tar_rom' service can be used within
the subsystem to provide the formerly built-in functionality.
The new 'chroot' tool at 'os/src/app/chroot' allows for executing
subsystems within chroot jails on Linux. For using the tool, please
refer to the test case 'os/run/chroot.run'. Fixes#37
With this patch clients of the RM service can state if they want a mapping
to be executable or not. This allows dataspaces to be mapped as
non-executable on Linux by default and as executable only if needed.
Partially fixes#176.
This patch reads program arguments from the config file and makes them
available to the application via the 'argc' and 'argv' arguments of the
'main()' function. The configuration syntax looks like this:
<config>
<arg value="...">
<arg value="...">
...
</config>
The 'value' attribute of the first <arg> node becomes 'argv[0]' and so on.
Fixes#184.
This patch introduces support for ROM sessions that update their
provided data during the lifetime of the session. The 'Rom_session'
interface had been extended with the new 'release()' and 'sigh()'
functions, which are needed to support the new protocol. All ROM
services have been updated to the new interface.
Furthermore, the patch changes the child policy of init
with regard to the handling of configuration files. The 'Init::Child'
used to always provide the ROM dataspace with the child's config file
via a locally implemented ROM service. However, for dynamic ROM
sessions, we need to establish a session to the real supplier of the ROM
data. This is achieved by using a new 'Child_policy_redirect_rom_file'
policy to handle the 'configfile' rather than handling the 'configfile'
case entirely within 'Child_config'.
To see the new facility in action, the new 'os/run/dynamic_config.run'
script provides a simple scenario. The config file of the test program
is provided by a service, which generates and updates the config data
at regular intervals.
In addition, new support has been added to let slaves use dynamic
reconfiguration. By using the new 'Child_policy_dynamic_rom_file', the
configuration of a slave can be changed dynamically at runtime via the
new 'configure()' function.
The config is provided as plain null-terminated string (instead of a
dataspace capability) because we need to buffer the config data anyway.
So there is no benefit of using a dataspace. For buffering configuration
data, a 'Ram_session' must be supplied. If no 'Ram_session' is specified
at construction time of a 'Slave_policy', no config is supplied to the
slave (which is still a common case).
An example for dynamically reconfiguring a slave is provided by
'os/run/dynamic_config_slave.run'.
The new 'swap' and 'realloc' functions are needed in scenarios where
'Attached_ram_dataspace' is used to implement double buffering. The
particular use case is the implementation of dynamic ROM sessions.
Use multiple load store instructions for 32 byte chunks in ARM-specific
blit-function, analog to x86 variant. Make the blit-function of x86 a
generic one, and provide needed utility functions for ARM and generic code.
Please refer issue #147 for discussion.
Separate spin-lock implementation from lock-implementation and put it into a
non-public header, so it can be re-used by the DDE kit's and Fiasco.OC's
capability-allocator spin lock. Fixes issue #123.
The ROM prefetcher service can be used to prefetch complete ROM files,
which is handy when using the iso9660 server (which normally reads file
content block-wise on demand). The server used to perform the
prefetching upon request of the respective ROM session. This patch adds
a facility for prefetching a predefined list of files. It is primarily
intended for eagerly fetching live-CD content in the background after
having passed the first boot stage.
This patch makes use of the recently added support for const RPC
functions by turning 'Framebuffer::Session::mode()' and
'Input::Session::is_pending()' into const functions.
Linux DDE used to implement Linux spin locks based on 'dde_kit_lock'.
This works fine if a spin lock is initialized only once and used
infinitely. But if spin locks are initialized on-the-fly at a high rate,
each initialization causes the allocation of a new 'dde_kit_lock'.
Because in contrast to normal locks, spinlocks cannot be explicitly
destroyed, the spin-lock emulating locks are never freed. To solve the
leakage of locks, there seems to be no other way than to support the
semantics as expected by the Linux drivers. Hence, this patch introduces
a DDE Kit API for spin locks.
The new 'Slave_policy' and 'Slave' classes are built upon the existing
child framework. They support the implementation of scenarios where a
service is started as a child of the client. This is usefull for
employing an existing service implementation as a local utility or
plugin.
The 'mode_sigh' function allows the client to receive notifications
about server-side display-mode changes. To respond to such a signal, the
client can use the new 'release' function, which acknowledges the mode
change at the server and frees the original framebuffer dataspace. Via a
subsequent call of 'dataspace', a framebuffer dataspace corresponding to
the new mode can be obtained. Related to issue #11.
As a preliminary step for working on issue #11, this patch revisits the
'Framebuffer::info' RPC call. Instead of using C-style out paramters,
the new 'mode()' RPC call returns the mode information as an object of
type 'Mode'. Consequently, mode-specific functions such as
'bytes_per_pixel' have been moved to the new 'Framebuffer::Mode' class.
The probing and I/O resource allocation is done only once at the
creation time of the first session. When closing and re-opening the
session, the '_device' object is simply reused. This patch fixes#92.
This patch prevents 'fb_sdl' from wrongly using SDL headers located in
the libports repository. We have to make sure to use the headers
installed on the host system.
