Very simple implementation of deadline scheduling. Works by storing a
single word in each thread containing a deadline, setting it (as a
delta from "now") via a single new API call, and using it as extra
input to the existing thread priority comparison function when
priorities are equal.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
This patch adds a set of priorities at the (numerically) lowest end of
the range which have "meta-irq" behavior. Runnable threads at these
priorities will always be scheduled before threads at lower
priorities, EVEN IF those threads are otherwise cooperative and/or
have taken a scheduler lock.
Making such a thread runnable in any way thus has the effect of
"interrupting" the current task and running the meta-irq thread
synchronously, like an exception or system call. The intent is to use
these priorities to implement "interrupt bottom half" or "tasklet"
behavior, allowing driver subsystems to return from interrupt context
but be guaranteed that user code will not be executed (on the current
CPU) until the remaining work is finished.
As this breaks the "promise" of non-preemptibility granted by the
current API for cooperative threads, this tool probably shouldn't be
used from application code.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Leading/trailing whitespace in prompts requires ugly workarounds in
genrest.py, as e.g. *prompt * is invalid RST. strip() all prompts in
Kconfiglib and get rid of the genrest.py workarounds. Add a warning too.
The Kconfiglib update has some unrelated cleanups and fixes (that won't
affect Zephyr).
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
This replaces the existing scheduler (but not priority handling)
implementation with a somewhat simpler one. Behavior as to thread
selection does not change. New features:
+ Unifies SMP and uniprocessing selection code (with the sole
exception of the "cache" trick not being possible in SMP).
+ The old static multi-queue implementation is gone and has been
replaced with a build-time choice of either a "dumb" list
implementation (faster and significantly smaller for apps with only
a few threads) or a balanced tree queue which scales well to
arbitrary numbers of threads and priority levels. This is
controlled via the CONFIG_SCHED_DUMB kconfig variable.
+ The balanced tree implementation is usable symmetrically for the
wait_q abstraction, fixing a scalability glitch Zephyr had when many
threads were waiting on a single object. This can be selected via
CONFIG_WAITQ_FAST.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
In order to mitigate Spectre variant 2 (branch target injection), use
retpolines for indirect jumps and calls.
The newly-added hidden CONFIG_X86_NO_SPECTRE flag, which is disabled
by default, must be set by a x86 SoC if its CPU performs speculative
execution. Most targets supported by Zephyr do not, so this is
set to "y" by default.
A new setting, CONFIG_RETPOLINE, has been added to the "Security
Options" sections, and that will be enabled by default if
CONFIG_X86_NO_SPECTRE is disabled.
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
To make Zephyr builds more reproducible, default to disabling build
timestamps. Expand the documentation for CONFIG_BUILD_TIMESTAMP to
explain that enabling it will make the build unreproducible.
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Move posix layer from 'kernel' to 'lib' folder as it is not
a core kernel feature.
Fixed posix header file dependencies as part of the move and
also removed NEWLIBC related macros from posix headers.
Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
* ring_bufffer is in lib, so move the Kconfig out of the kernel.
* move one Kconfig used for json to lib/Kconfig alongside other
Kconfigs.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
This is a component of address space layout randomization that we can
implement even though we have a physical address space.
Support for upward-growing stacks omitted for now, it's not done
currently on any of our current or planned architectures.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Simply define the Kconfig variables in this patch so they can be used
in later patches. Define MP_NUM_CPUS correctly on esp32. No code
changes.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
The existing __swap() mechanism is too high level for some
applications because of its scheduler-awareness. This introduces a
new _arch_switch() mechanism, which is a simpler primitive that looks
like:
void _arch_switch(void *handle, void **old_handle_out);
The new thread handle (typically just a stack pointer) is specified
explicitly instead of being picked up from the scheduler by
per-architecture code, and on return the "old" thread handle that got
switched out is returned through the pointer.
The new primitive (currently available only on xtensa) is selected
when CONFIG_USE_SWITCH is "y". A new C _Swap() implementation based
on this primitive is then added which operates compatibly.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Remove references to k_mem_pool_defrag and any related bits associated
with mem_pool defrag that don't make sense anymore.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
This adds CONFIG_EXECUTE_XOR_WRITE, which is enabled by default on
systems that support controlling whether a page can contain executable
code. This is also known as W^X[1].
Trying to add a memory domain with a page that is both executable and
writable, either for supervisor mode threads, or for user mode threads,
will result in a kernel panic.
There are few cases where a writable page should also be executable
(JIT compilers, which are most likely out of scope for Zephyr), so an
option is provided to disable the check.
Since the memory domain APIs are executed in supervisor mode, a
determined person could bypass these checks with ease. This is seen
more as a way to avoid people shooting themselves in the foot.
[1] https://en.wikipedia.org/wiki/W%5EX
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
Add the following application-facing memory domain APIs:
k_mem_domain_init() - to initialize a memory domain
k_mem_domain_destroy() - to destroy a memory domain
k_mem_domain_add_partition() - to add a partition into a domain
k_mem_domain_remove_partition() - to remove a partition from a domain
k_mem_domain_add_thread() - to add a thread into a domain
k_mem_domain_remove_thread() - to remove a thread from a domain
A memory domain would contain some number of memory partitions.
A memory partition is a memory region (might be RAM, peripheral
registers, flash...) with specific attributes (access permission,
e.g. privileged read/write, unprivileged read-only, execute never...).
Memory partitions would be defined by set of MPU regions or MMU tables
underneath.
A thread could only belong to a single memory domain any point in time
but a memory domain could contain multiple threads.
Threads in the same memory domain would have the same access permission
to the memory partitions belong to the memory domain.
The memory domain APIs are used by unprivileged threads to share data
to the threads in the same memory and protect sensitive data from
threads outside their domain. It is not only for improving the security
but also useful for debugging (unexpected access would cause exception).
Jira: ZEP-2281
Signed-off-by: Chunlin Han <chunlin.han@linaro.org>
All system calls made from userspace which involve pointers to kernel
objects (including device drivers) will need to have those pointers
validated; userspace should never be able to crash the kernel by passing
it garbage.
The actual validation with _k_object_validate() will be in the system
call receiver code, which doesn't exist yet.
- CONFIG_USERSPACE introduced. We are somewhat far away from having an
end-to-end implementation, but at least need a Kconfig symbol to
guard the incoming code with. Formal documentation doesn't exist yet
either, but will appear later down the road once the implementation is
mostly finalized.
- In the memory region for RAM, the data section has been moved last,
past bss and noinit. This ensures that inserting generated tables
with addresses of kernel objects does not change the addresses of
those objects (which would make the table invalid)
- The DWARF debug information in the generated ELF binary is parsed to
fetch the locations of all kernel objects and pass this to gperf to
create a perfect hash table of their memory addresses.
- The generated gperf code doesn't know that we are exclusively working
with memory addresses and uses memory inefficently. A post-processing
script process_gperf.py adjusts the generated code before it is
compiled to work with pointer values directly and not strings
containing them.
- _k_object_init() calls inserted into the init functions for the set of
kernel object types we are going to support so far
Issue: ZEP-2187
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Partial implementation of the IEEE 1003.1 pthread API, including
mutexes and condition variables in their default behaviors, and
pthread barrier objects. The rwlock and spinlocks abstractions are
not supported in this commit (both only make sense in the presence of
multiple SMP processors).
Note that this is the IPC mechanisms only. The thread creation API
itself is unsupported: Zephyr threads work differently from pthreads
and don't port cleanly in all cases. Likewise the "_INITIALIZER"
macros from pthreads don't work cleanly here, and _DECLARE macros have
been provided to statically initialize pthread primitives in a manner
more native to Zephyr
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Save some memory for small memory systems when running ztests. We have
our own stack in ztest so we should be able to get away reducing down
the main stack.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Adds common and Kinetis-specific adc device tree properties, and updates
all Kinetis SoC and board dts files to include adc nodes.
Jira: ZEP-1396
Signed-off-by: Maureen Helm <maureen.helm@nxp.com>
Introduce a configurable boot delay option (defaulting to none) that
happens right after printing a boot delay banner, #before calling
main() in kernel/init.c:_main(), before taking timestamps for _main()
and once all the infrastructure is in place. Move also the boot banner
to happen after this delay.
The rationale for this is some boards will boot really fast and print
out some test case output in the serial port before the system that is
monitoring the serial port is able to read from the serial port.
This happens in MCUs whose serial port is embedded in a USB connection
which also is used to power the MCU board. When powering it on by
powering the USB port, there is a time it takes the host system to
detect the USB connection, enumerate the serial port, configure it and
load, start and read from the serial port. At this time, it might have
printed the output of the serial port.
While manually it is possible to press a reset button, on automation
setups this adds a lot of overhead and cabling or modifications to the
MCU that are easier (and cheaper) to overcome with this delay. Other
options (like using a separate serial line) might not be possible or
add a lot of cabling and cost, plus it'd also add extra build
configuration.
Change-Id: I2f4d1ba356de6cefa19b4ef5c9f19f87885d4dfd
Signed-off-by: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Commit 1bc2fdc70 ("dts: arm: STM32 boards use DT to configure I2C")
added a new Kconfig option, HAS_DTS_I2C, which should be set when the
target supports configuration of I2C peripherals via Device Tree.
Currently, STM32 targets select this. However, the fact that
HAS_DTS_I2C has no default is causing prompting when building Zephyr
on other targets with DTS. To avoid this and allow builds to complete
as usual, have HAS_DTS_I2C default to n.
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
Configure I2C using DT for the following STM32 boards:
disco_l475_iot1
nucleo_f401re
96b_carbon
olimexino_stm32
Signed-off-by: Yannis Damigos <giannis.damigos@gmail.com>
This patck adds the stack information into the k_thread data structure.
The information will be set by when creating a new thread (_new_thread)
and will be used by the scheduling process.
Change-Id: Ibe79fe92a9ef8bce27bf8616d8e0c878508c267d
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@linaro.org>
First step to removing legacy APIs, this will be a wakeup call for this
still using legacy APIs before we completely remove them.
Change-Id: I32db62ff73efaa7eb5ab9ebc4d4fdc4a7c34ae56
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
When enabling CONFIG_FP_SHARING on ARM, 64 extra bytes are necessary
on the stack of each task in order to save FPU registers S16 to S31.
In the case of the idle stack, the default value of 256 bytes is too
small. As described in ZEP-1470, when the idle task is scheduled out,
floating point registers are saved, which corrupts the stack frame
(especially the saved PC value). When scheduling the idle task, the
restored PC will jump to nowhere, leading to a Usage Fault.
Increase the size of the idle stack by 64 bytes to fix this issue.
JIRA: ZEP-1470
Change-Id: Ib800cd51e5189dda8bf59332db661c21399db3e3
Signed-off-by: Florian Vaussard <florian.vaussard@heig-vd.ch>
Xtensa port uses more stack than others. This was discussed with the team and
we agreed that this can be accepted for the first beta.
We will investigate this later to see how to avoid allocating coproc registers
for the system threads in order to reduce the stack overhead. However this
will not be before the port is considered stable.
Change-Id: Icd5b2b0ab68d0906b5408f35f081b100acabc010
Signed-off-by: Mazen NEIFER <mazen@nestwave.com>
This patch adds support for using device tree configuration files for
configuring ARM platforms.
In this patch, only the FLASH_SIZE, SRAM_SIZE, NUM_IRQS, and
NUM_IRQ_PRIO_BITS were removed from the Kconfig options. A minimal set
of options were removed so that it would be easier to work through the
plumbing of the build system.
It should be noted that the host system must provide access to the
device tree compiler (DTC). The DTC can usually be installed on host
systems through distribution packages or by downloading and compiling
from https://git.kernel.org/pub/scm/utils/dtc/dtc.git
This patch also requires the Python yaml package.
This change implements parts of each of the following Jira:
ZEP-1304
ZEP-1305
ZEP-1306
ZEP-1307
ZEP-1589
Change-Id: If1403801e19d9d85031401b55308935dadf8c9d8
Signed-off-by: Andy Gross <andy.gross@linaro.org>
This flag is no longer necessary and TICKLESS_IDLE will be
enabled by default if SYS_POWER_MANAGEMENT is enabled.
Jira: ZEP-1325
Change-Id: Ic6cd4b8dc0a17c6a413cabf6509b215a4558318d
Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>
k_poll() is similar to the POSIX poll() API in spirit in that it allows
a single thread to monitor multiple events without actively polling
them, but rather pending for one or more to become ready. Such events
can be a direct event, or kernel objects (currently only semaphores and
fifos).
When a kernel object being polled on is ready, it is not "given" to the
poller: the poller must then acquire it via the regular API for the
object (e.g. k_sem_take()). Only one thread can poll on a particular
object at one time. These restrictions mean that k_poll() is most
effective when a single thread monitors multiple events that are not
subject for contention. For example, being the sole reader on multiple
fifos, or the only thread being signalled by multiple semaphores, or a
combination of both.
Change-Id: I7035a9baf4aa016fb87afc5f5c0f5f8cb216480f
Signed-off-by: Benjamin Walsh <walsh.benj@gmail.com>
Replace the existing Apache 2.0 boilerplate header with an SPDX tag
throughout the zephyr code tree. This patch was generated via a
script run over the master branch.
Also updated doc/porting/application.rst that had a dependency on
line numbers in a literal include.
Manually updated subsys/logging/sys_log.c that had a malformed
header in the original file. Also cleanup several cases that already
had a SPDX tag and we either got a duplicate or missed updating.
Jira: ZEP-1457
Change-Id: I6131a1d4ee0e58f5b938300c2d2fc77d2e69572c
Signed-off-by: David B. Kinder <david.b.kinder@intel.com>
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
