Commit graph

334 commits

Author SHA1 Message Date
Andy Ross
4d417034e9 kernel/Kconfig: Add prompt for CONFIG_TIMEOUT_64BIT
This was missing a prompt string, causing recent kconfig logic to
throw an error if an app tried to set it directly.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2020-05-06 06:05:03 -04:00
Andy Ross
38031dd599 kernel: Make the k_heap backend default for k_mem_pool
Legacy code can switch back to the original implementation where it
needs it, but we don't want new code to be unintentionally dependent
on the behavior of the older allocator.  The new one is a better
general purpose choice.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2020-04-14 10:05:55 -07:00
Andy Ross
8f0959c7b1 kernel: Add k_mem_pool compatibility layer on top of k_heap
Add a shim layer implementing the legacy k_mem_pool APIs backed by a
k_heap instead of the original implementation.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2020-04-14 10:05:55 -07:00
Anas Nashif
b90fafd6a0 kernel: remove unused offload workqueue option
Those are used only in tests, so remove them from kernel Kconfig and set
them in the tests that use them directly.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2020-04-12 18:42:27 -04:00
Andy Ross
4c7b77a716 kernel/timeout: Add absolute timeout APIs
Add support for "absolute" timeouts, which are expressed relative to
system uptime instead of deltas from current time.  These allow for
more race-resistant code to be written by allowing application code to
do a single timeout computation, once, and then reuse the timeout
value even if the thread wakes up and needs to suspend again later.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2020-03-31 19:40:47 -04:00
Andy Ross
cfeb07eded kernel/timeout: Enable 64 bit timeout precision
Add a CONFIG_TIMEOUT_64BIT kconfig that, when selected, makes the
k_ticks_t used in timeout computations pervasively 64 bit.  This will
allow much longer timeouts and much faster (i.e. more precise) tick
rates.  It also enables the use of absolute (not delta) timeouts in an
upcoming commit.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2020-03-31 19:40:47 -04:00
Andy Ross
7832738ae9 kernel/timeout: Make timeout arguments an opaque type
Add a k_timeout_t type, and use it everywhere that kernel API
functions were accepting a millisecond timeout argument.  Instead of
forcing milliseconds everywhere (which are often not integrally
representable as system ticks), do the conversion to ticks at the
point where the timeout is created.  This avoids an extra unit
conversion in some application code, and allows us to express the
timeout in units other than milliseconds to achieve greater precision.

The existing K_MSEC() et. al. macros now return initializers for a
k_timeout_t.

The K_NO_WAIT and K_FOREVER constants have now become k_timeout_t
values, which means they cannot be operated on as integers.
Applications which have their own APIs that need to inspect these
vs. user-provided timeouts can now use a K_TIMEOUT_EQ() predicate to
test for equality.

Timer drivers, which receive an integer tick count in ther
z_clock_set_timeout() functions, now use the integer-valued
K_TICKS_FOREVER constant instead of K_FOREVER.

For the initial release, to preserve source compatibility, a
CONFIG_LEGACY_TIMEOUT_API kconfig is provided.  When true, the
k_timeout_t will remain a compatible 32 bit value that will work with
any legacy Zephyr application.

Some subsystems present timeout (or timeout-like) values to their own
users as APIs that would re-use the kernel's own constants and
conventions.  These will require some minor design work to adapt to
the new scheme (in most cases just using k_timeout_t directly in their
own API), and they have not been changed in this patch, instead
selecting CONFIG_LEGACY_TIMEOUT_API via kconfig.  These subsystems
include: CAN Bus, the Microbit display driver, I2S, LoRa modem
drivers, the UART Async API, Video hardware drivers, the console
subsystem, and the network buffer abstraction.

k_sleep() now takes a k_timeout_t argument, with a k_msleep() variant
provided that works identically to the original API.

Most of the changes here are just type/configuration management and
documentation, but there are logic changes in mempool, where a loop
that used a timeout numerically has been reworked using a new
z_timeout_end_calc() predicate.  Also in queue.c, a (when POLL was
enabled) a similar loop was needlessly used to try to retry the
k_poll() call after a spurious failure.  But k_poll() does not fail
spuriously, so the loop was removed.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2020-03-31 19:40:47 -04:00
Flavio Ceolin
fbeaa0a510 kernel: Stack pointer random depends on MULTITHREADING
Don't pretend with have stack randomization without multithreading.
When multithreading is disabled the "main" thread never starts. Zephyr
will run on the stack used for the z_cstart(), which on most
architectures is the interrupt stack.

Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
2020-03-02 22:49:37 +02:00
Ulf Magnusson
40b49e22ea kernel: kconfig: Make SCHED_IPI_SUPPORTED invisible
Toggling this symbol probably doesn't make sense, because the
architecture is already known when Kconfig runs.

SCHED_IPI_SUPPORTED is enabled through being selected by the ARC_CONNECT
(maybe that one shouldn't be configurable either) and X86_64 symbols.

Note that it's not possible to disable the symbol when it's being
selected, so trying to turn it off on e.g. X86_64 won't work either.

Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
2020-01-20 18:38:10 -05:00
Ulf Magnusson
1404aaf099 kconfig: Remove '# hidden' comment on ARCH_HAS_CUSTOM_BUSY_WAIT
Straggler. See commit 41713244b3 ("kconfig: Remove '# Hidden' comments
on promptless symbols").

Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
2020-01-06 13:34:00 -05:00
Ulf Magnusson
bd9962d8d9 kconfig: Remove '# hidden' comments on promptless symbols
Same deal as in commit 41713244b3 ("kconfig: Remove '# Hidden' comments
on promptless symbols"). I forgot to do a case-insensitive search.

Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
2020-01-03 11:38:40 +01:00
Anas Nashif
8d2675010a kernel: update SCHED_CPU_MASK Kconfig doc
Fix reference to APIs and reformat kconfig help message.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2019-12-18 20:25:33 -05:00
David Leach
aa91113af7 kernel: Kconfig: Define dependencies for STACK_CANARIES
STACK_CANARIES relies on random value for the canarie so
ENTROPY_GENERATOR or TEST_RANDOM_GENERATOR needs to be
selected to get sys_rand32_get included in the build.

Fixes: #20587

Signed-off-by: David Leach <david.leach@nxp.com>
2019-11-15 10:13:15 -06:00
Andrew Boie
4f77c2ad53 kernel: rename z_arch_ to arch_
Promote the private z_arch_* namespace, which specifies
the interface between the core kernel and the
architecture code, to a new top-level namespace named
arch_*.

This allows our documentation generation to create
online documentation for this set of interfaces,
and this set of interfaces is worth treating in a
more formal way anyway.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2019-11-07 15:21:46 -08:00
Ulf Magnusson
1f38ea77ba kconfig: Clean up 'config FOO' (two spaces) definitions
Must've been copy-pasted around.

Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
2019-11-04 17:31:27 -05:00
Ulf Magnusson
bd6e04411e kconfig: Clean up header comments and make them consistent
Use this short header style in all Kconfig files:

    # <description>

    # <copyright>
    # <license>

    ...

Also change all <description>s from

    # Kconfig[.extension] - Foo-related options

to just

    # Foo-related options

It's clear enough that it's about Kconfig.

The <description> cleanup was done with this command, along with some
manual cleanup (big letter at the start, etc.)

    git ls-files '*Kconfig*' | \
        xargs sed -i -E '1 s/#\s*Kconfig[\w.-]*\s*-\s*/# /'

Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
2019-11-04 17:31:27 -05:00
Ulf Magnusson
975de21858 kconfig: Global whitespace/consistency cleanup
Clean up space errors and use a consistent style throughout the Kconfig
files. This makes reading the Kconfig files more distraction-free, helps
with grepping, and encourages the same style getting copied around
everywhere (meaning another pass hopefully won't be needed).

Go for the most common style:

 - Indent properties with a single tab, including for choices.

   Properties on choices work exactly the same syntactically as
   properties on symbols, so not sure how the no-indentation thing
   happened.

 - Indent help texts with a tab followed by two spaces

 - Put a space between 'config' and the symbol name, not a tab. This
   also helps when grepping for definitions.

 - Do '# A comment' instead of '#A comment'

I tweaked Kconfiglib a bit to find most of the stuff.

Some help texts were reflowed to 79 columns with 'gq' in Vim as well,
though not all, because I was afraid I'd accidentally mess up
formatting.

Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
2019-11-01 15:53:23 +01:00
Charles E. Youse
64300a7ec3 kernel/Kconfig: clamp number of CPUs to 4
This maximum is implicit in the kernel support for SMP, e.g.,
kernel/init.c and kernel/smp.c assume CONFIG_MP_NUM_CPUS <= 4.

Signed-off-by: Charles E. Youse <charles.youse@intel.com>
2019-10-07 19:46:55 -04:00
Andrew Boie
2c1fb971e0 kernel: rename __swap
This is part of the core kernel -> architecture API and
has been renamed to z_arch_swap().

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2019-09-30 15:25:55 -04:00
Andrew Boie
7fae2bbc18 tests: increase main stack size for x86 with ztest
Some options like stack canaries use more stack space,
and on x86 this is not quite enough for ztest's main
thread stack to be 512 bytes.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2019-08-05 13:25:50 +02:00
Nicolas Pitre
1f4b5ddd0f riscv32: rename to riscv
With the upcoming riscv64 support, it is best to use "riscv" as the
subdirectory name and common symbols as riscv32 and riscv64 support
code is almost identical. Then later decide whether 32-bit or 64-bit
compilation is wanted.

Redirects for the web documentation are also included.

Then zephyrbot complained about this:

"
New files added that are not covered in CODEOWNERS:

dts/riscv/microsemi-miv.dtsi
dts/riscv/riscv32-fe310.dtsi

Please add one or more entries in the CODEOWNERS file to cover
those files
"

So I assigned them to those who created them. Feel free to readjust
as necessary.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-08-02 13:54:48 -07:00
Andy Ross
669730f030 kernel: Crank up default tick rate
When tickless is available, all existing devices can handle much
higher timing precision than 10ms.  A 10kHz default seems acceptable
without introducing too much range limitation (rollover for a signed
time delta will happen at 2.5 days).  Leave the 100 Hz default in
place for ticked configurations, as those are going to be special
purpose usages where the user probably actually cares about interrupt
rate.

Note that the defaulting logic interacts with an obscure trick:
setting the tick rate to zero would indicate "no clock exists" to the
configuration (some platforms use this to drop code from the build).
But now that becomes a kconfig cycle, so to break it we expose
CONFIG_SYS_CLOCK_EXISTS as an app-defined tunable and not a derived
value from the tick rate.  Only one test actually did this.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2019-07-02 22:52:29 -04:00
Andrew Boie
38129ce1a6 kernel: fix CONFIG_THREAD_NAME from user mode.
This mechanism had multiple problems:

- Missing parameter documentation strings.
- Multiple calls to k_thread_name_set() from user
  mode would leak memory, since the copied string was never
  freed
- k_thread_name_get() returns memory to user mode
  with no guarantees on whether user mode can actually
  read it; in the case where the string was in thread
  resource pool memory (which happens when k_thread_name_set()
  is called from user mode) it would never be readable.
- There was no test case coverage for these functions
  from user mode.

To properly fix this, thread objects now have a buffer region
reserved specifically for the thread name. Setting the thread
name copies the string into the buffer. Getting the thread name
with k_thread_name_get() still returns a pointer, but the
system call has been removed. A new API k_thread_name_copy()
is introduced to copy the thread name into a destination buffer,
and a system call has been provided for that instead.

We now have full test case coverge for these APIs in both user
and supervisor mode.

Some of the code has been cleaned up to place system call
handler functions in proximity with their implementations.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2019-07-01 16:29:45 -07:00
Anas Nashif
76d9d7806d x86: remove unused and x86 only latency benchmark
We do have a multi-architecture latency benchmark now, this one was x86
only, was never used or compiled in and is out-dated.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2019-06-03 09:42:00 -07:00
Carles Cufi
201fdf0aec kernel: Fix usage of CONFIG_SYS_CLOCK_EXISTS
When compiling the kernel with CONFIG_SYS_CLOCK_TICKS_PER_SEC=0,
the CONFIG_SYS_CLOCK_EXISTS internal variable is unset.
This completely disables timer handling in the kernel, but a couple of
spots missed the required conditional compilation.

Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>
2019-05-15 10:44:59 +02:00
Andrew Boie
0f6c9a5a04 kernel: adjust default main stack for riscv
We are just at the knife edge with 512, with stack
overflows being observed with stack canaries enabled.
Given the special case for the idle thread stack size
on this arch, seems reasonable to increase it here
for that arch.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2019-05-03 13:30:16 -07:00
Andrew Boie
afda764ee6 kernel: increase workq sizes if COVERAGE=y
The defaults are too small if coverage is enabled.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2019-05-02 07:23:35 -04:00
Flavio Ceolin
2e0095a99c security: kernel: Fix STACK_POINTER_RANDOM dependency
STACK_POINTER_RANDOM depends on a random generator, this can be either a
non-random generator (used for testing purpose) or a real random
generator. Make this dependency explicitly in Kconfig to avoid linking
problems.

Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
2019-05-01 08:34:13 -07:00
Wentong Wu
8646a8e4f5 tests/kernel/mem_protect/stackprot: stack size adjust
revert commit 3e255e968 which is to adjust stack size
on qemu_x86 platform for coverage test, but break other
platform's CI test.

Fixes: #15379.

Signed-off-by: Wentong Wu <wentong.wu@intel.com>
2019-04-12 10:06:43 -04:00
Wentong Wu
3e255e968a tests: adjust stack size for qemu_x86's coverage test
for SDK 0.10.0, it consumes more stack size when coverage
enabled, so adjust stack size to fix stack overflow issue.

Fixes: #15206.

Signed-off-by: Wentong Wu <wentong.wu@intel.com>
2019-04-11 17:59:39 -04:00
Wentong Wu
b991962a2e tests: adjust stack size for qemu_x86 and mps2_an385's coverage test
for SDK 0.10.0, it consumes more stack size when coverage enabled
on qemu_x86 and mps2_an385 platform, adjust stack size for most of
the test cases, otherwise there will be stack overflow.

Fixes: #14500.

Signed-off-by: Wentong Wu <wentong.wu@intel.com>
2019-04-04 08:23:13 -04:00
David Brown
22029275d3 kernel: Clarify warning about no multithreading
Clarify the warning in the help for CONFIG_MULTITHREADING to make it
clear that many things will break if this is set to 'n'.

Signed-off-by: David Brown <david.brown@linaro.org>
2019-03-28 09:49:59 -04:00
Andy Ross
42ed12a387 kernel/sched: arch/x86_64: Support synchronous k_thread_abort() in SMP
Currently thread abort doesn't work if a thread is currently scheduled
on a different CPU, because we have no way of delivering an interrupt
to the other CPU to force the issue.  This patch adds a simple
framework for an architecture to provide such an IPI, implements it
for x86_64, and uses it to implement a spin loop in abort for the case
where a thread is currently scheduled elsewhere.

On SMP architectures (xtensa) where no such IPI is implemented, we
fall back to waiting on an arbitrary interrupt to occur.  This "works"
for typical code (and all current tests), but of course it cannot be
guaranteed on such an architecture that k_thread_abort() will return
in finite time (e.g. the other thread on the other CPU might have
taken a spinlock and entered an infinite loop, so it will never
receive an interrupt to terminate itself)!

On non-SMP architectures this patch changes no code paths at all.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2019-03-13 19:15:20 +01:00
Pawel Dunaj
b87920bf3c kernel: Make heap smallest object size configurable
Allow application to chose the size of the smallest object taken from
the heap.

Signed-off-by: Pawel Dunaj <pawel.dunaj@nordicsemi.no>
2019-03-12 11:56:31 +01:00
Andrew Boie
576ebf4991 kernel: add config for Spectre V1 mitigation
This is off by default, but may be selected by the arch
configuration.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2019-03-11 09:54:04 -07:00
Ioannis Glaropoulos
edc9e4d245 arch: arm: userspace: Force arch-specific user local data reservation
This commit forces architecture-specific implementation for
initializing the are for user mode local thread data. This
has been enforced already for ARC. We now do the same for ARM.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2019-03-09 11:57:24 -08:00
Andrew Boie
d3c89fea4f kernel: move CONFIG_RETPOLINE definition
Retpolines were never completely implemented, even on x86.
Move this particular Kconfig to only concern itself with
the assembly code, and don't default it on ever since we
prefer SSBD instead.

We can restore the common kernel-wide CONFIG_RETPOLINE once
we have an end-to-end implementation.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2019-03-01 12:35:04 -08:00
Aurelien Jarno
992f29a1bc arch: make __ramfunc support transparent
Instead of having to enable ramfunc support manually, just make it
transparently available to users, keeping the MPU region disabled if not
used to not waste a MPU region. This however wastes 24 bytes of code
area when the MPU is disabled and 48 bytes when it is enabled, and
probably a dozen of CPU cycles during boot. I believe it is something
acceptable.

Note that when XIP is used, code is already in RAM, so the __ramfunc
keyword does nothing, but does not generate an error.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2019-02-22 11:36:50 -08:00
qianfan Zhao
e1cc657941 arm: Placing the functions which holds __ramfunc into '.ramfunc'
Using __ramfunc to places a function in RAM instead of Flash.
Code that for example reprograms flash at runtime can't execute
from flash, in that case must placing code into RAM.

This commit create a new section named '.ramfunc' in link scripts,
all functions has __ramfunc keyword saved in thats sections and
will load from flash to sram after the system booted.

Fixes: #10253

Signed-off-by: qianfan Zhao <qianfanguijin@163.com>
2019-02-22 11:36:50 -08:00
Ioannis Glaropoulos
228702e6e1 kernel: minor syntax fix in Kconfig
Minor style (syntax) fix in the help text of symbol
config EXECUTION_BENCHMARKING.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2019-02-12 08:29:33 -06:00
Andrew Boie
41f6011c36 userspace: remove APPLICATION_MEMORY feature
This was never a long-term solution, more of a gross hack
to get test cases working until we could figure out a good
end-to-end solution for memory domains that generated
appropriate linker sections. Now that we have this with
the app shared memory feature, and have converted all tests
to remove it, delete this feature.

To date all userspace APIs have been tagged as 'experimental'
which sidesteps deprecation policies.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2019-02-08 07:04:30 -05:00
Andy Ross
ab46b1b3c5 kernel/sched: CPU mask affinity/pinning API
This adds a simple implementation of SMP CPU affinity to Zephyr.  The
API is simple and doesn't try to invent abstractions like "cpu sets".
Each thread has an enable/disable flag associated with each CPU in the
system, and the bits can be turned on and off (for threads that are
not currently runnable, of course) using an easy three-function API.

Because the implementation picked requires enumerating runnable
threads in priority order looking for one that match the current CPU,
this is not a good fit for the SCALABLE or MULTIQ scheduler backends,
so it currently can be enabled only for SCHED_DUMB (which is the
default anyway).  Fancier algorithms do exist, but even the best of
them scale as O(N_CPUS), so aren't quite constant time and often
require significant memory overhead to keep separate lists for
different cpus/sets.

The intended use here is for apps that want to "pin" threads to
specific CPUs for latency control, or conversely to prevent certain
threads from taking time on specific CPUs to leave them free for fast
response.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2019-02-01 21:37:24 -05:00
Sebastian Bøe
5a58da57fd Kconfig: STACK_CANARIES: Correct the help text
The help text has been stating that CONFIG_STACK_CANARIES will
silently be ignored when the compiler does not support them. But this
is not the desired behaviour of CONFIG_STACK_CANARIES[1].

This patch corrects the help text to state that an error will occur if
this feature is enabled, but not supported.

[1] "I would much rather see the build break if someone tries to
enable the stack canaries, and the compiler doesn't support
it. Because what happens now is that if someone enables this option,
and there is no support, the build will succeed but there are no
actual stack canaries in place, and unless the user is paying close
attention to the cmake test output they will have no idea."
--
https://github.com/zephyrproject-rtos/zephyr/issues/5019

Signed-off-by: Sebastian Bøe <sebastian.boe@nordicsemi.no>
2019-01-23 09:44:09 +01:00
Adithya Baglody
76ee02b6b3 Gcov: Added Kconfig changes needed by Gcov.
This patch addes the required changes in the Kconfig files.

Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>
2019-01-16 06:12:33 -05:00
Andy Ross
7f42dbaf48 kernel: Add CONFIG_SWAP_NONATOMIC flag
On ARM, _Swap() isn't atomic and a hardware interrupt can land after
the (irq_locked) caller has entered _Swap() but before the context
switch actually happens.  This will require some platform-specific
workarounds in a few places in the scheduler.

This commit is just the Kconfig and selection on ARM.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2019-01-15 13:06:35 +01:00
Sebastian Bøe
204f05b23a kconfig: Minor comments and 'help' text fixes
Minor comments and 'help' text fixes.

Signed-off-by: Sebastian Bøe <sebastian.boe@nordicsemi.no>
2018-12-30 16:24:50 -05:00
Sebastian Bøe
f42ed32dc5 Kconfig: Hide SMP and USE_SWITCH from unsupported platforms
Don't present USE_SWITCH and SMP to user applications that are
configuring for platforms that do not support SMP or USE_SWITCH.

Signed-off-by: Sebastian Bøe <sebastian.boe@nordicsemi.no>
2018-12-30 16:24:50 -05:00
Sebastian Bøe
21d69579f5 kconfig: Have the 'SMP' option depend on 'USE_SWITCH'
SMP requires the new-style '_arch_switch' to be enabled. To prevent
users from creating invalid configurations where SMP is enabled while
_arch_switch is not, we add a dependency from SMP to USE_SWITCH.

Signed-off-by: Sebastian Bøe <sebastian.boe@nordicsemi.no>
2018-12-30 16:24:50 -05:00
Sebastian Bøe
4019bda695 kconfig: Disable 'RETPOLINE' on unsupported platforms
RETPOLINE has been enabled by default on most platforms, but it is
only supported on X86.

Features should only be enabled if they are supported and active on
the given platform. To rectify this we have RETPOLINE depend on X86,
the only platform on which it is implemented.

Signed-off-by: Sebastian Bøe <sebastian.boe@nordicsemi.no>
2018-12-30 16:24:50 -05:00
Andy Ross
c0a184c067 drivers/timer: Select tickless via driver kconfig flag
Add a TICKLESS_CAPABLE kconfig variable which is used by the kernel to
select tickless mode's default automatically on drivers that support
it (rather than having to set the default per-board).  Select it from
the ARM SysTick and Intel HPET drivers.

Also remove the old qemu_cortex_m3 default settings which this
replaces.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2018-11-13 17:10:07 -05:00