Commit Graph

24 Commits

Author SHA1 Message Date
Martin Stein
685f509a43 timer connection: no interpolation on arm w/o hw
On ARM, we do not have a component-local hardware time-source. The ARM
performance counter has no reliable frequency as the ARM idle command
halts the counter. Thus, we do not do local time interpolation on ARM.
Except we're on the HW kernel. In this case we can read out the kernel
time instead.

Ref #2435
2017-05-31 17:50:28 +02:00
Norman Feske
a1df4fee44 base: restructure signal-submit initialization
This patch allows core's 'Signal_transmitter' implementation to sidestep
the 'Env::Pd' interface and thereby adhere to a stricter layering within
core. The 'Signal_transmitter' now uses - on kernels that depend on it -
a dedicated (and fairly freestanding) RPC proxy mechanism for signal
deliver, instead of channeling signals through the 'Pd_session::submit'
RPC function.
2017-05-31 13:16:12 +02:00
Martin Stein
c70fed29f7 os/timer: interpolate time via timestamps
Previously, the Genode::Timer::curr_time always used the
Timer_session::elapsed_ms RPC as back end.  Now, Genode::Timer reads
this remote time only in a periodic fashion independently from the calls
to Genode::Timer::curr_time. If now one calls Genode::Timer::curr_time,
the function takes the last read remote time value and adapts it using
the timestamp difference since the remote-time read. The conversion
factor from timestamps to time is estimated on every remote-time read
using the last read remote-time value and the timestamp difference since
the last remote time read.

This commit also re-works the timeout test. The test now has two stages.
In the first stage, it tests fast polling of the
Genode::Timer::curr_time. This stage checks the error between locally
interpolated and timer-driver time as well as wether the locally
interpolated time is monotone and sufficiently homogeneous. In the
second stage several periodic and one-shot timeouts are scheduled at
once. This stage checks if the timeouts trigger sufficiently precise.

This commit adds the new Kernel::time syscall to base-hw. The syscall is
solely used by the Genode::Timer on base-hw as substitute for the
timestamp. This is because on ARM, the timestamp function uses the ARM
performance counter that stops counting when the WFI (wait for
interrupt) instruction is active. This instruction, however is used by
the base-hw idle contexts that get active when no user thread needs to
be scheduled.  Thus, the ARM performance counter is not a good choice for
time interpolation and we use the kernel internal time instead.

With this commit, the timeout library becomes a basic library. That means
that it is linked against the LDSO which then provides it to the program it
serves. Furthermore, you can't use the timeout library anymore without the
LDSO because through the kernel-dependent LDSO make-files we can achieve a
kernel-dependent timeout implementation.

This commit introduces a structured Duration type that shall successively
replace the use of Microseconds, Milliseconds, and integer types for duration
values.

Open issues:

* The timeout test fails on Raspberry PI because of precision errors in the
  first stage. However, this does not render the framework unusable in general
  on the RPI but merely is an issue when speaking of microseconds precision.

* If we run on ARM with another Kernel than HW the timestamp speed may
  continuously vary from almost 0 up to CPU speed. The Timer, however,
  only uses interpolation if the timestamp speed remained stable (12.5%
  tolerance) for at least 3 observation periods. Currently, one period is
  100ms, so its 300ms. As long as this is not the case,
  Timer_session::elapsed_ms is called instead.

  Anyway, it might happen that the CPU load was stable for some time so
  interpolation becomes active and now the timestamp speed drops. In the
  worst case, we would now have 100ms of slowed down time. The bad thing
  about it would be, that this also affects the timeout of the period.
  Thus, it might "freeze" the local time for more than 100ms.

  On the other hand, if the timestamp speed suddenly raises after some
  stable time, interpolated time can get too fast. This would shorten the
  period but nonetheless may result in drifting away into the far future.
  Now we would have the problem that we can't deliver the real time
  anymore until it has caught up because the output of Timer::curr_time
  shall be monotone. So, effectively local time might "freeze" again for
  more than 100ms.

  It would be a solution to not use the Trace::timestamp on ARM w/o HW but
  a function whose return value causes the Timer to never use
  interpolation because of its stability policy.

Fixes #2400
2017-05-31 13:16:11 +02:00
Norman Feske
3d7b92ea50 Generalize ABI mechanism to shared objects
This patch make the ABI mechanism available to shared libraries other
than Genode's dynamic linker. It thereby allows us to introduce
intermediate ABIs at the granularity of shared libraries. This is useful
for slow-moving ABIs such as the libc's interface but it will also
become handy for the package management.

To implement the feature, the build system had to be streamlined a bit.
In particular, archive dependencies and shared-lib dependencies are now
handled separately, and the global list of 'SHARED_LIBS' is no more.
Now, the variable with the same name holds the per-target list of shared
libraries used by the target.
2017-01-13 13:06:54 +01:00
Norman Feske
c450ddcb3d Disambiguate kernel-specific file names
This patch removes possible ambiguities with respect to the naming of
kernel-dependent binaries and libraries. It also removes the use of
kernel-specific global side effects from the build system. The reach of
kernel-specific peculiarities has thereby become limited to the actual
users of the respective 'syscall-<kernel>' libraries.

Kernel-specific build artifacts are no longer generated at magic places
within the build directory (like okl4's includes, or the L4 build
directories of L4/Fiasco and Fiasco.OC, or the build directories of
various kernels). Instead, such artifacts have been largely moved to the
libcache. E.g., the former '<build-dir>/l4/' build directory for the L4
build system resides at '<build-dir>/var/libcache/syscall-foc/build/'.
This way, the location is unique to the kernel. Note that various tools
are still generated somewhat arbitrarily under '<build-dir>/tool/' as
there is no proper formalism for building host tools yet.

As the result of this work, it has become possible to use a joint Genode
build directory that is usable with all kernels of a given hardware
platform. E.g., on x86_32, one can now seamlessly switch between linux,
nova, sel4, okl4, fiasco, foc, and pistachio without rebuilding any
components except for core, the kernel, the dynamic linker, and the timer
driver. At the current stage, such a build directory must still be
created manually. A change of the 'create_builddir' tool will follow to
make this feature easily available.

This patch also simplifies various 'run/boot_dir' plugins by removing
the option for an externally hosted kernel. This option remained unused
for many years now.

Issue #2190
2016-12-23 16:51:32 +01:00
Norman Feske
f54c85e045 Genode application binary interface (ABI)
This patch decouples the kernel-specific implementation of the dynamic
linker from its kernel-agnostic binary interface. The name of the
kernel-specific dynamic linker binary now corresponds to the kernel,
e.g., 'ld-linux.lib.so' or 'ld-nova.lib.so'. Applications are no longer
linked directly against a concrete instance of the dynamic linker but
against a shallow stub called 'ld.lib.so'. This stub contains nothing
but the symbols provided by the dynamic linker. It thereby represents
the Genode ABI.

At system-integration time, the kernel-specific run/boot_dir back ends
integrate the matching the kernel-specific variant of the dynamic linker
as 'ld.lib.so' into the boot image.

The ABI symbol file for the dynamic linker is located at
'base/lib/symbols/ld'. It contains the joint ABI of all supported
architectures. The new utility 'tool/abi_symbols' eases the creation of
such an ABI symbol file for a given shared library. Its result should be
manually inspected and edited as needed.

The patch removes the 'syscall' library from 'base_libs.mk' to avoid
polluting the kernel-agnostic ABI with kernel-specific interfaces.

Issue #2190
Issue #2195
2016-12-23 16:50:28 +01:00
Norman Feske
ccffbb0dfc Build dynamically linked executables by default
Fixes #2184
2016-12-14 11:22:27 +01:00
Norman Feske
57ec61fb4b base-linux: omit stack-area init for lx_hybrid
Fixes #2030
2016-07-11 13:31:37 +02:00
Norman Feske
88b358c5ef Unification of native_capability.h
This patch establishes the sole use of generic headers across all
kernels. The common 'native_capability.h' is based on the version of
base-sel4. All traditional L4 kernels and Linux use the same
implementation of the capability-lifetime management. On base-hw, NOVA,
Fiasco.OC, and seL4, custom implementations (based on their original
mechanisms) are used, with the potential to unify them further in the
future.

This change achieves binary compatibility of dynamically linked programs
across all kernels.

Furthermore, the patch introduces a Native_capability::print method,
which allows the easy output of the kernel-specific capability
representation using the base/log.h API.

Issue #1993
2016-07-11 13:07:37 +02:00
Norman Feske
40a5af42eb Clean up base-library structure
This patch moves the base library from src/base to src/lib/base,
flattens the library-internal directory structure, and moves the common
parts of the library-description files to base/lib/mk/base.inc and
base/lib/mk/base-common.inc.

Furthermore, the patch fixes a few cosmetic issues (whitespace and
comments only) that I encountered while browsing the result.

Fixes #1952
2016-05-09 13:24:11 +02:00
Norman Feske
7274ca997d Remove Genode::Process from API
This patch makes the former 'Process' class private to the 'Child'
class and changes the constructor of the 'Child' in a way that
principally enables the implementation of single-threaded runtime
environments that virtualize the CPU, PD, and RAM services. The
new interfaces has become free from side effects. I.e., instead
of implicitly using Genode::env()->rm_session(), it takes the reference
to the local region map as argument. Also, the handling of the dynamic
linker via global variables is gone. Now, the linker binary must be
provided as constructor argument.

Fixes #1949
2016-05-09 13:10:52 +02:00
Norman Feske
511acad507 Consolidate RM service into PD session
This patch integrates three region maps into each PD session to
reduce the session overhead and to simplify the PD creation procedure.
Please refer to the issue cited below for an elaborative discussion.

Note the API change:

With this patch, the semantics of core's RM service have changed. Now,
the service is merely a tool for creating and destroying managed
dataspaces, which are rarely needed. Regular components no longer need a
RM session. For this reason, the corresponding argument for the
'Process' and 'Child' constructors has been removed.

The former interface of the 'Rm_session' is not named 'Region_map'. As a
minor refinement, the 'Fault_type' enum values are now part of the
'Region_map::State' struct.

Issue #1938
2016-05-09 13:10:51 +02:00
Norman Feske
051e84c4b4 Move server API concept to base framework
This commit introduces the new `Component` interface in the form of the
headers base/component.h and base/entrypoint.h. The os/server.h API
has become merely a compatibilty wrapper and will eventually be removed.
The same holds true for os/signal_rpc_dispatcher.h. The mechanism has
moved to base/signal.h and is now called 'Signal_handler'.

Since the patch shuffles headers around, please do a 'make clean' in the
build directory.

Issue #1832
2016-04-11 11:51:46 +02:00
Norman Feske
7f73e5e879 base: hide internals of the Thread API
This patch moves details about the stack allocation and organization
the base-internal headers. Thereby, I replaced the notion of "thread
contexts" by "stacks" as this term is much more intuitive. The fact that
we place thread-specific information at the bottom of the stack is not
worth introducing new terminology.

Issue #1832
2016-03-07 12:34:46 +01:00
Norman Feske
3473955212 base-linux/nova: unify include/rm_session/client.h
By moving the stub implementation to rm_session_client.cc, we can use
the generic base/include/rm_session/client.h for base-linux and
base-nova and merely use platform-specific implementations.

Issue #1832
2016-03-07 12:34:45 +01:00
Norman Feske
e6729316ff base: uniform base-internal header structure
This patch establishes a common organization of header files
internal to the base framework. The internal headers are located at
'<repository>/src/include/base/internal/'. This structure has been
choosen to make the nature of those headers immediately clear when
included:

  #include <base/internal/lock_helper.h>

Issue #1832
2016-03-07 12:34:45 +01:00
Norman Feske
be496c6dc1 base: remove kernel-specific base/sleep.h
With this patch, the platform differences reside solely in the
implementation of the base library.

Issue #1832
2016-03-07 12:34:44 +01:00
Norman Feske
62b1c55399 Integrate CAP session into PD session
This patch integrates the functionality of the former CAP session into
the PD session and unifies the approch of supplementing the generic PD
session with kernel-specific functionality. The latter is achieved by
the new 'Native_pd' interface. The kernel-specific interface can be
obtained via the Pd_session::native_pd accessor function. The
kernel-specific interfaces are named Nova_native_pd, Foc_native_pd, and
Linux_native_pd.

The latter change allowed for to deduplication of the
pd_session_component code among the various base platforms.

To retain API compatibility, we keep the 'Cap_session' and
'Cap_connection' around. But those classes have become mere wrappers
around the PD session interface.

Issue #1841
2016-03-07 12:34:44 +01:00
Stefan Kalkowski
ed52d5a211 Introduce 'spec' subdirectories to outline aspects
Instead of holding SPEC-variable dependent files and directories inline
within the repository structure, move them into 'spec' subdirectories
at the corresponding levels, e.g.:

  repos/base/include/spec
  repos/base/mk/spec
  repos/base/lib/mk/spec
  repos/base/src/core/spec
  ...

Moreover, this commit removes the 'platform' directories. That term was
used in an overloaded sense. All SPEC-relative 'platform' directories are
now named 'spec'. Other files, like for instance those related to the
kernel/architecture specific startup library, where moved from 'platform'
directories to explicit, more meaningful places like e.g.: 'src/lib/startup'.

Fix #1673
2015-09-16 13:58:50 +02:00
Christian Helmuth
98def2488a thread: move Thread_base::myself() to separate file
The thread library (thread.cc) in base-foc shared 95% of the code with
the generic implementation except myself(). Therefore, its
implementation is now separated from the other generic sources into
myself.cc, which allows base-foc to use a foc-specific primitive to
enable our base libraries in L4Linux.

Issue #1491
2015-05-06 10:55:17 +02:00
Alexander Boettcher
faa25e1df6 base: make irq_session asynchronous
second step

options: factor out common parts of irq_session_component.cc
options: use on foc arm no proxy threads

Fixes #1456
2015-04-23 16:47:58 +02:00
Alexander Boettcher
1f8fad8fa1 base: refactor signal_transmitter::submit
Move it to platform specific .cc file, so that it may get re-implemented
platform specifically if needed.

Issue #1446
2015-03-19 09:32:52 +01:00
Christian Prochaska
078883fda3 base: interface for D- and I-cache synchronization
On ARM, when machine instructions get written into the data cache
(for example by a JIT compiler), one needs to make sure that the
instructions get written out to memory and read from memory into
the instruction cache before they get executed. This functionality
is usually provided by a kernel syscall and this patch adds a generic
interface for Genode applications to use it.

Fixes #1153.
2014-05-27 11:14:45 +02:00
Norman Feske
ca971bbfd8 Move repositories to 'repos/' subdirectory
This patch changes the top-level directory layout as a preparatory
step for improving the tools for managing 3rd-party source codes.
The rationale is described in the issue referenced below.

Issue #1082
2014-05-14 16:08:00 +02:00