By separating the session-interface concerns from the mechanics of the
dataspace creation, the code becomes simpler to follow, and the RAM
session can be more easily merged with the PD session in a subsequent
step.
Issue #2407
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
With this, we get rid of platform specific timer interfaces. The new
Timer class does the same as the old Clock class and has a generic
interface. The old Timer class was merely used by the old Clock class.
Also, we get rid of having only one timer instance which we tell with
each method call for which CPU it shall be done. Instead now each Cpu
object has its own Timer member that knows the CPU it works for.
Also, rename all "tics" to "ticks".
Fixes#2347
Previously we did write the SPSR via an MSR instruction without
additional flags. Unfortunately, this tells the CPU to write the
register only partially. This often isn't a problem as the users PSR
reset value normally is conform to our expectations but in some cases
(e.g. PSR endianess bit on WandBoard core #4) the reset value is bad.
Thus, we have to add the CXSF flags (access Control + eXtension + Status
+ Flags) so the CPU overwrites the entire register.
Fixes#2254
This patch reduces the number of exception types by facilitating
globally defined exceptions for common usage patterns shared by most
services. In particular, RPC functions that demand a session-resource
upgrade not longer reflect this condition via a session-specific
exception but via the 'Out_of_ram' or 'Out_of_caps' types.
Furthermore, the 'Parent::Service_denied', 'Parent::Unavailable',
'Root::Invalid_args', 'Root::Unavailable', 'Service::Invalid_args',
'Service::Unavailable', and 'Local_service::Factory::Denied' types have
been replaced by the single 'Service_denied' exception type defined in
'session/session.h'.
This consolidation eases the error handling (there are fewer exceptions
to handle), alleviates the need to convert exceptions along the
session-creation call chain, and avoids possible aliasing problems
(catching the wrong type with the same name but living in a different
scope).
This patch mirrors the accounting and trading scheme that Genode employs
for physical memory to the accounting of capability allocations.
Capability quotas must now be explicitly assigned to subsystems by
specifying a 'caps=<amount>' attribute to init's start nodes.
Analogously to RAM quotas, cap quotas can be traded between clients and
servers as part of the session protocol. The capability budget of each
component is maintained by the component's corresponding PD session at
core.
At the current stage, the accounting is applied to RPC capabilities,
signal-context capabilities, and dataspace capabilities. Capabilities
that are dynamically allocated via core's CPU and TRACE service are not
yet covered. Also, the capabilities allocated by resource multiplexers
outside of core (like nitpicker) must be accounted by the respective
servers, which is not covered yet.
If a component runs out of capabilities, core's PD service prints a
warning to the log. To observe the consumption of capabilities per
component in detail, the PD service is equipped with a diagnostic
mode, which can be enabled via the 'diag' attribute in the target
node of init's routing rules. E.g., the following route enables the
diagnostic mode for the PD session of the "timer" component:
<default-route>
<service name="PD" unscoped_label="timer">
<parent diag="yes"/>
</service>
...
</default-route>
For subsystems based on a sub-init instance, init can be configured
to report the capability-quota information of its subsystems by
adding the attribute 'child_caps="yes"' to init's '<report>'
config node. Init's own capability quota can be reported by adding
the attribute 'init_caps="yes"'.
Fixes#2398
This patch replaces the 'Parent::Quota_exceeded',
'Service::Quota_exceeded', and 'Root::Quota_exceeded' exceptions
by the single 'Insufficient_ram_quota' exception type.
Furthermore, the 'Parent' interface distinguished now between
'Out_of_ram' (the child's RAM is exhausted) from
'Insufficient_ram_quota' (the child's RAM donation does not suffice to
establish the session).
This eliminates ambiguities and removes the need to convert exception
types along the path of the session creation.
Issue #2398
This patch upgrades the cap-space slab only if the kernel runs out of
entries, instead of consuming as much PD-session quota as possible.
Until now, the behavior worked well because the cap-space slab was the
only consumer of PD-session quota. However, once we start accounting all
PD session meta data - and eventually merging the PD and RAM services -
the aggressive scheme stands in the way.
Issue #2398
This commit moves the headers residing in `repos/base/include/spec/*/drivers`
to `repos/base/include/drivers/defs` or repos/base/include/drivers/uart`
respectively. The first one contains definitions about board-specific MMIO
iand RAM addresses, or IRQ lines. While the latter contains device driver
code for UART devices. Those definitions are used by driver implementations
in `repos/base-hw`, `repos/os`, and `repos/dde-linux`, which now need to
include them more explicitely.
This work is a step in the direction of reducing 'SPEC' identifiers overall.
Ref #2403
By installing the core object to bin/, we follow the same convention as
for regular binaries. This, in turn, enables us to ship core in a
regular binary archive. The patch also adjusts the run tool to pick up
the core object from bin/ for the final linking stage.
The size of the whole table and table entries were exchanged for PML4,
leading to out-of-bound accesses for addesses >= 2^39. Some constants
were lacking type suffixes causing integer overflows.
Added assertions to catch out-of-bound accesses early on.
Fixes#2210Fixes#2211
If we do the tics-to-us translation with one division and multiplication
over the whole argument, like before, we loose microseconds granularity
although the timer frequency allows for such granularity. Thus, we treat
the most significant half and the least significant half of the tics
value separate. Each half is shifted to the best bit position for the
translation, then translated, and then shifted back.
Ref #2347
* Acknowledge receive of page-fault signal with ack_signal,
but restart thread execution separately
* use kill_signal_context when disolving a pager_object to prevent race
* Remove bureaucracy in form of Thread_event and Signal_ack_handler
* remove dead code in riscv, namely Thread_base definition
* translation_table_insertions function for ARM drops out,
which was overcautious
There was a race when the component entrypoint wanted to do
'wait_and_dispatch_one_signal'. In this function it raises a flag for
the signal proxy thread to notice that the entrypoint also wants to
block for signals. When the flag is set and the signal proxy wakes up
with a new signal, it tried to cancel the blocking of the entrypoint.
However, if the entrypoint had not reached the signal blocking at this
point, the cancel blocking failed without a solution. Now, the new
Kernel::cancel_next_signal_blocking call solves the problem by storing a
request to cancel the next signal blocking of a thread immediately
without blocking itself.
Ref #2284
Put the initialization of the cpu cores, setup of page-tables, enabling of
MMU and caches into a separate component that is only used to bootstrap
the kernel resp. core.
Ref #2092
This aspect was always enabled when creating a build directory for hw,
but is not enabled anymore due to recent build directory unifications.
On the other hand it is needed for jitter entropy anyway.
Ref #2190
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
This cleans up the syscalls that are mainly used to control the
scheduling readiness of a thread. The different use cases and
requirements were somehow mixed together in the previous interface. The
new syscall set is:
1) pause_thread and resume_thread
They don't affect the state of the thread (IPC, signalling, etc.) but
merely decide wether the thread is allowed for scheduling or not, the
so-called pause state. The pause state is orthogonal to the thread state
and masks it when it comes to scheduling. In contrast to the stopped
state, which is described in "stop_thread and restart_thread", the
thread state and the UTCB content of a thread may change while in the
paused state. However, the register state of a thread doesn't change
while paused. The "pause" and "resume" syscalls are both core-restricted
and may target any thread. They are used as back end for the CPU session
calls "pause" and "resume". The "pause/resume" feature is made for
applications like the GDB monitor that transparently want to stop and
continue the execution of a thread no matter what state the thread is
in.
2) stop_thread and restart_thread
The stop syscall can only be used on a thread in the non-blocking
("active") thread state. The thread then switches to the "stopped"
thread state in wich it explicitely waits for a restart. The restart
syscall can only be used on a thread in the "stopped" or the "active"
thread state. The thread then switches back to the "active" thread state
and the syscall returns whether the thread was stopped. Both syscalls
are not core-restricted. "Stop" always targets the calling thread while
"restart" may target any thread in the same PD as the caller. Thread
state and UTCB content of a thread don't change while in the stopped
state. The "stop/restart" feature is used when an active thread wants to
wait for an event that is not known to the kernel. Actually the syscalls
are used when waiting for locks and on thread exit.
3) cancel_thread_blocking
Does cleanly cancel a cancelable blocking thread state (IPC, signalling,
stopped). The thread whose blocking was cancelled goes back to the
"active" thread state. It may receive a syscall return value that
reflects the cancellation. This syscall doesn't affect the pause state
of the thread which means that it may still not get scheduled. The
syscall is core-restricted and may target any thread.
4) yield_thread
Does its best that a thread is scheduled as few as possible in the
current scheduling super-period without touching the thread or pause
state. In the next superperiod, however, the thread is scheduled
"normal" again. The syscall is not core-restricted and always targets
the caller.
Fixes#2104
The initial stack is solely used to initialize the Genode environment
along with the application stack located in the stack area. It never
executes application code. Hence, we can make it small. To check that it
is not dimensioned too small, the patch introduces a sanity check right
before switching to the application stack.
This is a redesign of the root and parent interfaces to eliminate
blocking RPC calls.
- New session representation at the parent (base/session_state.h)
- base-internal root proxy mechanism as migration path
- Redesign of base/service.h
- Removes ancient 'Connection::KEEP_OPEN' feature
- Interface change of 'Child', 'Child_policy', 'Slave', 'Slave_policy'
- New 'Slave::Connection'
- Changed child-construction procedure to be compatible with the
non-blocking parent interface and to be easier to use
- The child's initial LOG session, its binary ROM session, and the
linker ROM session have become part of the child's envirenment.
- Session upgrading must now be performed via 'env.upgrade' instead
of performing a sole RPC call the parent. To make RAM upgrades
easier, the 'Connection' provides a new 'upgrade_ram' method.
Issue #2120
Replace 'dump()' debug utilities within Allocator_avl with Output::print
equivalents, and use the new Avl_tree::for_each utility to simplify
the implementation.
Ref #2159
Instead of solving the problem to deliver ROM modules to core while booting
differently for the several kernels (multi-boot, elfweaver, core re-linking),
this commit unifies the approaches. It always builds core as a library, and
after all binaries are built from a run-script, the run-tool will link an
ELF image out of the core-library and all boot modules. Thereby, core can
access its ROM modules directly.
This approach now works for all kernels except Linux.
With this solution, there is no [build_dir]/bin/core binary available anymore.
For debugging purposes you will find a core binary without boot modules, but
with debug symbols under [run_dir].core.
Fix#2095
base generic code:
* Remove unused verbosity code from mmio framework
* Remove escape sequence end heuristic from LOG
* replace Core_console with Core_log (no format specifiers)
* move test/printf to test/log
* remove `printf()` tests from the log test
* check for exact match of the log test output
base-fiasco:
* remove unused Fiasco::print_l4_threadid function
base-nova:
* remove unused hexdump utility from core
base-hw:
* remove unused Kernel::Thread::_print_* debug utilities
* always print resource summary of core during startup
* remove Kernel::Ipc_node::pd_label (not used anymore)
base*:
* Turn `printf`,`PWRN`, etc. calls into their log equivalents
Ref #1987Fix#2119
* Remove 'test' routine from kernel/core
* Move 'cpu_scheduler' and 'double_list' test to user-land
* Remove 'hw_info' target at all (can be recycled in a topic branch)
Besides adapting the components to the use of base/log.h, the patch
cleans up a few base headers, i.e., it removes unused includes from
root/component.h, specifically base/heap.h and
ram_session/ram_session.h. Hence, components that relied on the implicit
inclusion of those headers have to manually include those headers now.
While adjusting the log messages, I repeatedly stumbled over the problem
that printing char * arguments is ambiguous. It is unclear whether to
print the argument as pointer or null-terminated string. To overcome
this problem, the patch introduces a new type 'Cstring' that allows the
caller to express that the argument should be handled as null-terminated
string. As a nice side effect, with this type in place, the optional len
argument of the 'String' class could be removed. Instead of supplying a
pair of (char const *, size_t), the constructor accepts a 'Cstring'.
This, in turn, clears the way let the 'String' constructor use the new
output mechanism to assemble a string from multiple arguments (and
thereby getting rid of snprintf within Genode in the near future).
To enforce the explicit resolution of the char * ambiguity, the 'char *'
overload of the 'print' function is marked as deleted.
Issue #1987