Nicolas Pitre points out that since these thread structs are just
dummies for the context swtiching, they can be presumed to be "write
only" and thus there's no point in having one per CPU, everyone can
share the same one.
The only gotcha is that we never really documented (nor really have a
place to document) that rule, so it's not theoretically impossible for
an architecture to read back what it might have written underneath
arch_switch(). Leave this in a separate commit for bisection
purposes, but the risk seems very low.
Signed-off-by: Andy Ross <andyross@google.com>
After a k_thread_abort(), the resulting thread struct is documented as
unused/free memory that may be re-used (for example, to respawn a new
thread).
But in the special case of aborting the current thread from within an
ISR, that wasn't quite happening. The scheduler cleanup would
complete, but the architecture layer would still try to context switch
away from the aborted thread on exit, and that can include writes to
the now-reused thread struct! The specifics will depend on
architecture (some do a full context save on entry, most don't), but
in the case of USE_SWITCH=y it will at the very least write the
switch_handle field.
Fix this simply, with a per-cpu "switch dummy" thread struct for use
as a target for context switches like this. There is some non-trivial
memory cost to that; thread structs on many architectures are large.
Pleasingly, this also addresses a known deadlock on SMP: because the
"spin in ISR" step now happens as the very last stage of
k_thread_abort() handling, the existing scheduler lock works to
serialize calls such that it's impossible for a cycle of threads to
independently decide to spin on each other: at least one will see
itself as "already aborting" and break the cycle.
Fixes#64646
Signed-off-by: Andy Ross <andyross@google.com>
This reverts commit 61c70626a5.
This PR introduced 2 regressions in main CI:
71977 & 71978
Let's revert it by now to get main's CI passing again.
Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>
This reverts commit 20611f13ca.
This PR introduced 2 regressions in main CI:
71977 & 71978
Let's revert it by now to get main's CI passing again.
Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>
Nicolas Pitre points out that since these thread structs are just
dummies for the context swtiching, they can be presumed to be "write
only" and thus there's no point in having one per CPU, everyone can
share the same one.
The only gotcha is that we never really documented (nor really have a
place to document) that rule, so it's not theoretically impossible for
an architecture to read back what it might have written underneath
arch_switch(). Leave this in a separate commit for bisection
purposes, but the risk seems very low.
Signed-off-by: Andy Ross <andyross@google.com>
After a k_thread_abort(), the resulting thread struct is documented as
unused/free memory that may be re-used (for example, to respawn a new
thread).
But in the special case of aborting the current thread from within an
ISR, that wasn't quite happening. The scheduler cleanup would
complete, but the architecture layer would still try to context switch
away from the aborted thread on exit, and that can include writes to
the now-reused thread struct! The specifics will depend on
architecture (some do a full context save on entry, most don't), but
in the case of USE_SWITCH=y it will at the very least write the
switch_handle field.
Fix this simply, with a per-cpu "switch dummy" thread struct for use
as a target for context switches like this. There is some non-trivial
memory cost to that; thread structs on many architectures are large.
Pleasingly, this also addresses a known deadlock on SMP: because the
"spin in ISR" step now happens as the very last stage of
k_thread_abort() handling, the existing scheduler lock works to
serialize calls such that it's impossible for a cycle of threads to
independently decide to spin on each other: at least one will see
itself as "already aborting" and break the cycle.
Fixes#64646
Signed-off-by: Andy Ross <andyross@google.com>
Currently, all devices are initialized at boot time (following their
level and priority order). This patch introduces deferred
initialization: by setting the property `zephyr,deferred-init` on a
device on the devicetree, Zephyr will not initialized the device.
To initialize such devices, one has to call `device_init()`.
Deferred initialization is done by grouping all deferred devices on a
different ELF section. In this way, there's no need to consume more
memory to keep track of deferred devices. When `device_init()` is
called, Zephyr will scan the deferred devices section and call the
initialization function for the matching device. As this scanning is
done only during deferred device initialization, its cost should be
bearable.
Signed-off-by: Ederson de Souza <ederson.desouza@intel.com>
Simple rename to align the kernel naming scheme. This is being
used throughout the tree, especially in the architecture code.
As this is not a private API internal to kernel, prefix it
appropriately with K_.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
Add a closing comment to the endif with the configuration
information to which the endif belongs too.
To make the code more clearer if the configs need adaptions.
Signed-off-by: Simon Hein <Shein@baumer.com>
Move out of thread and put directly in init.c where it is being used.
Also remove definition from kernel.h, this is an internal function and
should not be in a public header.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
The functions to manipulate the essential flag indeed operate on
threads, but they are misplaced in the thread implementation file. Put
them alongside other routines setting other thread flags and cleanup
headers a bit.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Some platforms already have .bss section zeroed-out externally before the
Zephyr initialization and there is no sence to zero it out the second time
from the SW.
Such boot-time optimization could be critical e.g. for RTL Simulation.
Signed-off-by: Alexander Razinkov <alexander.razinkov@syntacore.com>
The early random get function was making many wrong assumptions
about random subsys and entropy drivers. First, it was assuming
that entropy_get_entropy() would be ISR safe, that is not right,
the driver has an ISR safe callback and if it is not implemented
or not working it is not ok using the other callback.
Second, the fallback to the random subsys is even more problematic
since they can use kernel services to protect internal states and be
thread-safe.
Another incorrect thing in this function was the guard around it.
It was needed by features like stack randomization and stack canaries,
and not when those conditions were match. Just remove it and in case
it is not needed the linker will take care of it.
The drawback of this change is that in the absence of an entropy
generator with support to be called from ISR the randomness is very
weak.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Allow targets come up with their own early random generator
since the default can be NOT so random due constraints.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Rename z_early_boot_rand_get with z_early_rand_get to get consistent
with other early functions.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
rand32.h does not make much sense, since the random subsystem
provides more APIs than just getting a random 32 bits value.
Rename it to random.h and get consistently with other
subsystems.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Integrates object core statistics framework into the following
kernel objects:
sys_mem_blocks, k_mem_slab
threads, _cpu, z_kernel
Signed-off-by: Peter Mitsis <peter.mitsis@intel.com>
Refactors CPU usage (thread runtime stats) to make it easier to
integrate with the object core statistics framework.
Signed-off-by: Peter Mitsis <peter.mitsis@intel.com>
Add new option to use thread local storage for stack
canaries. This makes harder to find the canaries location
and value. This is made optional because there is
a performance and size penalty when using it.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Only set a cpu as active (on pm subsystem) when the cpu is effectively
initialized. We cannot assume on pm subsystem that all cpus were
initialized since when the option CONFIG_SMP_BOOT_DELAY is used cpus are
initialized on demand by the application.
Note that once cpus are properly initialized the subystem is able to track
their status.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Exception handler(arch/x86/core/ia32/excstub.S) may access
_kernel variable, it will lead to failure when enabled paging,
so make this critical variable pinned.
Signed-off-by: Qipeng Zha <qipeng.zha@intel.com>
Some devices do not need to perform any initialization, so allow the
init function to be NULL. In this case, the initialization code will
just mark the device as initialized, i.e. ready.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
As both C and C++ standards require applications running under an OS to
return 'int', adapt that for Zephyr to align with those standard. This also
eliminates errors when building with clang when not using -ffreestanding,
and reduces the need for compiler flags to silence warnings for both clang
and gcc.
Most of these changes were automated using coccinelle with the following
script:
@@
@@
- void
+ int
main(...) {
...
- return;
+ return 0;
...
}
Approximately 40 files had to be edited by hand as coccinelle was unable to
fix them.
Signed-off-by: Keith Packard <keithp@keithp.com>
The init infrastructure, found in `init.h`, is currently used by:
- `SYS_INIT`: to call functions before `main`
- `DEVICE_*`: to initialize devices
They are all sorted according to an initialization level + a priority.
`SYS_INIT` calls are really orthogonal to devices, however, the required
function signature requires a `const struct device *dev` as a first
argument. The only reason for that is because the same init machinery is
used by devices, so we have something like:
```c
struct init_entry {
int (*init)(const struct device *dev);
/* only set by DEVICE_*, otherwise NULL */
const struct device *dev;
}
```
As a result, we end up with such weird/ugly pattern:
```c
static int my_init(const struct device *dev)
{
/* always NULL! add ARG_UNUSED to avoid compiler warning */
ARG_UNUSED(dev);
...
}
```
This is really a result of poor internals isolation. This patch proposes
a to make init entries more flexible so that they can accept sytem
initialization calls like this:
```c
static int my_init(void)
{
...
}
```
This is achieved using a union:
```c
union init_function {
/* for SYS_INIT, used when init_entry.dev == NULL */
int (*sys)(void);
/* for DEVICE*, used when init_entry.dev != NULL */
int (*dev)(const struct device *dev);
};
struct init_entry {
/* stores init function (either for SYS_INIT or DEVICE*)
union init_function init_fn;
/* stores device pointer for DEVICE*, NULL for SYS_INIT. Allows
* to know which union entry to call.
*/
const struct device *dev;
}
```
This solution **does not increase ROM usage**, and allows to offer clean
public APIs for both SYS_INIT and DEVICE*. Note that however, init
machinery keeps a coupling with devices.
**NOTE**: This is a breaking change! All `SYS_INIT` functions will need
to be converted to the new signature. See the script offered in the
following commit.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
init: convert SYS_INIT functions to the new signature
Conversion scripted using scripts/utils/migrate_sys_init.py.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
manifest: update projects for SYS_INIT changes
Update modules with updated SYS_INIT calls:
- hal_ti
- lvgl
- sof
- TraceRecorderSource
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
tests: devicetree: devices: adjust test
Adjust test according to the recently introduced SYS_INIT
infrastructure.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
tests: kernel: threads: adjust SYS_INIT call
Adjust to the new signature: int (*init_fn)(void);
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
Add check to ensure that CONFIG_MP_NUM_CPUS and CONFIG_MP_MAX_NUM_CPUS
are set the same. This will at least cause a build issue for out of
tree users.
Signed-off-by: Kumar Gala <kumar.gala@intel.com>
Add the `zephyr,pm-device-runtime-auto` flag to `pm.yaml` and
`struct pm_device`.
This flag is intended to signify to the boot system that device runtime
PM should be automatically enabled on the device after the init function
has run.
Only run `pm_device_runtime_auto_enable` function on a device if
initialisation succeeded. This prevents actions being run on devices
that are not ready.
Signed-off-by: Jordan Yates <jordan.yates@data61.csiro.au>
Most of the time, z_cstart() is running on an arbitrary region
of memory as stack, where the necessary stack setup has not been
performed. This prevents stack protection to work correctly,
as the stack canary has not been populated. So mark z_cstart()
to have no stack protection at all inside the function to avoid
raising exception during boot.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This commit updates all in-tree code to use `CONFIG_CPP` instead of
`CONFIG_CPLUSPLUS`, which is now deprecated.
Signed-off-by: Stephanos Ioannidis <stephanos.ioannidis@nordicsemi.no>
The C++ standard requires the main() function to have the return type
of 'int' and does not allow the main() to be defined with the 'void'
return type. Moreover, GCC goes as far as to emit a hard error when the
'::main()' has the return type of `void`.
This commit introduces an option to instruct the Zephyr kernel to call
the 'int main(void)' instead of the 'void main(void)' in case a Zephyr
application defines main() in a C++ source file.
Signed-off-by: Stephanos Ioannidis <stephanos.ioannidis@nordicsemi.no>
Move runtime code to use arch_num_cpus() instead of CONFIG_MP_NUM_CPUS
and use CONFIG_MP_MAX_NUM_CPUS for ifdef and BUILD_ASSERT macros.
Signed-off-by: Kumar Gala <kumar.gala@intel.com>
The _SYS_INIT_LEVEL* definitions were used to indicate the index entry
into the levels array defined in init.c (z_sys_init_run_level). init.c
uses this information internally, so there is no point in exposing this
in a public header. It has been replaced with an enum inside init.c. The
device shell was re-using the same defines to index its own array. This
is a fragile design, the shell needs to be responsible of its own data
indexing. A similar situation happened with some unit tests.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
The function in charge of calling all init function was defined in
device.c, had a public prototype and was just used in init.c. Since this
is really an internal function tied to Kernel init code, move it to
init.c and make it static, there's no need to expose it publicly.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
The `ARCH` init level was added to solve a specific problem, call init
code (SYS_INIT/devices) before `z_cstart` in the `intel_adsp` platform.
The documentation claims it runs before `z_cstart`, but this is only
true if the SoC/arch takes care of calling:
```c
z_sys_init_run_level(_SYS_INIT_LEVEL_ARCH);
```
Which is only true for `intel_adsp` nowadays. So in practice, we now
have a platform specific init level. This patch proposes to do things in
a slightly different way. First, level name is renamed to `EARLY`, to
emphasize it runs in the early stage of the boot process. Then, it is
handled by the Kernel (inside `z_cstart()` before calling
`arch_kernel_init()`). This means that any platform can now use this
level. For `intel_adsp`, there should be no changes, other than
`gcov_static_init()` will be called before (I assume this will allow to
obtain coverage for code called in EARLY?).
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
Many device pointers are initialized at compile and never changed. This
means that the device pointer can be constified (immutable).
Automated using:
```
perl -i -pe 's/const struct device \*(?!const)(.*)= DEVICE/const struct
device *const $1= DEVICE/g' **/*.c
```
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
There's no point to doing this when the host OS clears all memory at
mapping time. And as it turns out, the __bss_end symbol it was
relying on actually comes from the host toolchain's linker, not our
own linker scripts (making it semi-dangerous to rely on). And it's
not present in clang/lld output anyway.
Signed-off-by: Andy Ross <andyross@google.com>
Files including <zephyr/kernel.h> do not have to include
<zephyr/zephyr.h>, a shim to <zephyr/kernel.h>.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
Rename the symbols used to denote the locations of the global
constructor lists and modify the Zephyr start-up code accordingly.
On POSIX systems this ensures that the native libc init code won't
find any constructors to run before Zephyr loads.
Fixes#39347, #36858
Signed-off-by: David Palchak <palchak@google.com>
In order to bring consistency in-tree, migrate all kernel code to the
new prefix <zephyr/...>. Note that the conversion has been scripted,
refer to zephyrproject-rtos#45388 for more details.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
The idle thread got an index suffix in #23536 to make it easier to
identify different idle threads on different cores. This looks out of
place on single-core devices when the idle thread is listed next to
other kernel threads, such as main.
Remove the idle thread index on single-core platforms, and replace all
references to this format in tests and documentation.
Signed-off-by: Trond Einar Snekvik <Trond.Einar.Snekvik@nordicsemi.no>
A reference to the entropy device can be obtained at compile time, so
avoid using device_get_binding().
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
There is an API to get an specific number of random bytes. There is
no need to re-implement this logic here.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Things had gotten a little tangled in there so let's do some cleanup.
Remove the distressingly-special-purpose z_reinit_idle_thread() hook
(which existed to support secondary core bringup when
SMP_BOOT_DELAY=y), and just fold that into a generic z_init_cpu(),
which we can call in obvious and symmetric ways from main
initialization, z_smp_init(), and z_smp_start_cpu() (the now-official
programmatic hook for starting cpus).
Remove the "#if CONFIG_MP_NUM_CPUS > 1" exclusions. These weren't
saving any code size and were propagating themselves into platform
layers trying to avoid build failures.
There are some "special" APIs added for SOF which need to go away in
favor of the newer/generic z_smp_start_cpu(). Collect them in one
place and put them under a "#ifdef CONFIG_SOF" to prevent them from
being used in Zephyr apps.
Move some function declarations that didn't have homes into
<kernel/thread.h>.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Commit 678b76e4b0 ("kernel/init.c: allow for memset/memcpy
alternatives during early boot") and commit da28829b64 ("kernel:
zero the bss section of OCM memory at boot time") were created
independently and missed changes from each other.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Zeroing the BSS and copying data to RAM with regular memset/memcpy may
cause problems when those functions are assuming a fully initialized
system for their optimizations to work e.g. some instructions require
an active MMU, but turning the MMU on needs the .bss section to be
cleared first, etc.
Commit c5b898743a ("aarch64: Fix alignment fault on z_bss_zero()")
provides a detailed explanation of such a case.
Replacing z_bss_zero() with an architecture specific one is problematic
as the former may see new sections added to it that would be missed by
the later. The same reasoning goes for z_data_copy().
Let's make maintenance much easier by providing weak versions of
memset/memcpy that can be overridden by architecture-specific safe
versions when needed.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
If a chosen entry exists for a memory area of type OCM, zero the OCM
memory's bss section at boot-time.
Signed-off-by: Immo Birnbaum <Immo.Birnbaum@weidmueller.com>
