Commit Graph

128 Commits (0d9649ca4514c32b8aaac31a3c56c7865fefcc94)

Author SHA1 Message Date
Gaurav-Aggarwal-AWS b9f488a713
Fix remarks emitted by IAR compiler (#763)
Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>
1 year ago
Moral-Hao bd720c316a
Bring the heap_4 improvements to secure_heap (#749)
This includes improvements like addition overflow checks,
readability improvements.
1 year ago
kar-rahul-aws 02be485e04
Update MPU wrapper for pcTaskGetName API (#737)
* Update MPU wrapper for pcTaskGetName

* Fix Formatting

* Fix mpu wrappers V1

---------

Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>
2 years ago
Moral-Hao a5bf4d9a7f
Improve the speed of split memory. (#738)
Co-authored-by: moral-hao <405197809@qq.com>
Co-authored-by: Nikhil Kamath <110539926+amazonKamath@users.noreply.github.com>
Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>
2 years ago
kar-rahul-aws b51a37314c
Update MPU wrapper for xTimerGenericCommand API (#734)
* Update xTimerGenericCommand API as per SMP branch

Signed-off-by: kar-rahul-aws <karahulx@amazon.com>

* Fix formatting

* Code review changes

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>

* Fix Formatting

---------

Signed-off-by: kar-rahul-aws <karahulx@amazon.com>
Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>
Co-authored-by: Gaurav Aggarwal <aggarg@amazon.com>
2 years ago
Zim Kalinowski 785250de45
Align some Linux and RL78 port types with other ports (#727) 2 years ago
Jeff Tenney b13e2698bb
Work around SysTick bug for QEMU ARMv8-M (#724)
* Set SysTick CLKSOURCE bit before enabling SysTick

* Use portNVIC_SYSTICK_CLK_BIT_CONFIG

The workaround now uses portNVIC_SYSTICK_CLK_BIT_CONFIG instead of
portNVIC_SYSTICK_CLK_BIT, which saves us from having to explain in the
comments why it's OK to temporarily set the CLKSOURCE bit even if the
user's FreeRTOS configuration clears the CLKSOURCE bit.

Using portNVIC_SYSTICK_CLK_BIT_CONFIG here still correctly prevents the
firmware from triggering the QEMU bug.
2 years ago
kar-rahul-aws 83da5fc958
Update portSTACK_REGION macro for continuity with user Regions (#713) 2 years ago
Jeff Tenney b375458aab
Add port-optimised task selection for ARMv8-M (#703)
Add port-optimised task selection for ARMv8-M
2 years ago
Soren Ptak 54b13568e4
Fix the comments in the CM3 and CM4 MPU Ports about the MPU Region numbers being loaded (#707)
Co-authored-by: Soren Ptak <skptak@amazon.com>
Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>
2 years ago
kar-rahul-aws 97050a17aa
Memory Protection Unit (MPU) Enhancements (#705)
Memory Protection Unit (MPU) Enhancements

This commit introduces a new MPU wrapper that places additional
restrictions on unprivileged tasks. The following is the list of changes
introduced with the new MPU wrapper:

1. Opaque and indirectly verifiable integers for kernel object handles:
   All the kernel object handles (for example, queue handles) are now
   opaque integers. Previously object handles were raw pointers.

2. Saving the task context in Task Control Block (TCB): When a task is
   swapped out by the scheduler, the task's context is now saved in its
   TCB. Previously the task's context was saved on its stack.

3. Execute system calls on a separate privileged only stack: FreeRTOS
   system calls, which execute with elevated privilege, now use a
   separate privileged only stack. Previously system calls used the
   calling task's stack. The application writer can control the size of
   the system call stack using new configSYSTEM_CALL_STACK_SIZE config
   macro.

4. Memory bounds checks: FreeRTOS system calls which accept a pointer
   and de-reference it, now verify that the calling task has required
   permissions to access the memory location referenced by the pointer.

5. System call restrictions: The following system calls are no longer
   available to unprivileged tasks:
    - vQueueDelete
    - xQueueCreateMutex
    - xQueueCreateMutexStatic
    - xQueueCreateCountingSemaphore
    - xQueueCreateCountingSemaphoreStatic
    - xQueueGenericCreate
    - xQueueGenericCreateStatic
    - xQueueCreateSet
    - xQueueRemoveFromSet
    - xQueueGenericReset
    - xTaskCreate
    - xTaskCreateStatic
    - vTaskDelete
    - vTaskPrioritySet
    - vTaskSuspendAll
    - xTaskResumeAll
    - xTaskGetHandle
    - xTaskCallApplicationTaskHook
    - vTaskList
    - vTaskGetRunTimeStats
    - xTaskCatchUpTicks
    - xEventGroupCreate
    - xEventGroupCreateStatic
    - vEventGroupDelete
    - xStreamBufferGenericCreate
    - xStreamBufferGenericCreateStatic
    - vStreamBufferDelete
    - xStreamBufferReset
   Also, an unprivileged task can no longer use vTaskSuspend to suspend
   any task other than itself.

We thank the following people for their inputs in these enhancements:
- David Reiss of Meta Platforms, Inc.
- Lan Luo, Xinhui Shao, Yumeng Wei, Zixia Liu, Huaiyu Yan and Zhen Ling
  of School of Computer Science and Engineering, Southeast University,
  China.
- Xinwen Fu of Department of Computer Science, University of
  Massachusetts Lowell, USA.
- Yuequi Chen, Zicheng Wang, Minghao Lin of University of Colorado
  Boulder, USA.
2 years ago
Evgeny Ermakov 891dcdf80a
Fix typos in comments for the AT91SAM7S port (#695)
Co-authored-by: RichardBarry <3073890+RichardBarry@users.noreply.github.com>
2 years ago
chinglee-iot aa012e8d82
Add constant type for portMAX_DELAY in port (#691)
Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>
2 years ago
chinglee-iot 9a6284262e
Fix typo in check comment of configMAX_SYSCALL_INTERRUPT_PRIORITY (#690) 2 years ago
chinglee-iot 17a46c252f
Use portTASK_FUNCTION_PROTO to replace portNORETURN (#688)
* Use portTASK_FUNCTION_PROTO to replace portNORETURN
2 years ago
chinglee-iot 4a35c97fec
Remove __NVIC_PRIO_BITS and configPRIO_BITS check in port (#683)
* Remove __NVIC_PRIO_BITS and configPRIO_BITS check in CM3, CM4 and ARMv8.
* Add hardware not implemented bits check. These bits should be zero.

---------

Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>
2 years ago
Devaraj Ranganna a07f649bd5
Armv8-M (except Cortex-M23) interrupt priority checking (#673)
* Armv8-M: Formatting changes

Signed-off-by: Devaraj Ranganna <devaraj.ranganna@arm.com>

* Armv8-M: Add support for interrupt priority check

FreeRTOS provides `FromISR` system calls which can be called directly
from interrupt service routines. It is crucial that the priority of
these ISRs is set to same or lower value (numerically higher) than that
of `configMAX_SYSCALL_INTERRUPT_PRIORITY`. For more information refer
to https://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html.

Add a check to trigger an assert when an ISR with priority higher
(numerically lower) than `configMAX_SYSCALL_INTERRUPT_PRIORITY` calls
`FromISR` system calls if `configASSERT` macro is defined.

In addition, add a config option
`configQEMU_DISABLE_INTERRUPT_PRIO_BITS_CHECK` to disable interrupt
priority check while running on QEMU. Based on the discussion
https://gitlab.com/qemu-project/qemu/-/issues/1122, The interrupt
priority bits in QEMU do not match the real hardware. Therefore the
assert that checks the number of implemented bits and __NVIC_PRIO_BITS
will always fail. The config option
 `configQEMU_DISABLE_INTERRUPT_PRIO_BITS_CHECK` should be defined in the
`FreeRTOSConfig.h` for QEMU targets.

Signed-off-by: Devaraj Ranganna <devaraj.ranganna@arm.com>

* Use SHPR2 for calculating interrupt priority bits

This removes the dependency on the secure software to mark the interrupt
as non-secure.

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>

---------

Signed-off-by: Devaraj Ranganna <devaraj.ranganna@arm.com>
Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>
Co-authored-by: Gaurav Aggarwal <aggarg@amazon.com>
Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>
2 years ago
Paul Bartell c1980cedb1 tree-wide: Unify formatting of __cplusplus ifdefs 2 years ago
Paul Bartell 5f19e34f87 portable/ARM_CM0: Add xPortIsInsideInterrupt
Add missing xPortIsInsideInterrupt function to Cortex-M0 port.
2 years ago
Paul Bartell 714e543247 Format portmacro.h in arm CM0 ports 2 years ago
Paul Bartell 686b6e62eb
ARMv7M: Adjust implemented priority bit assertions (#665)
Adjust assertions related to the CMSIS __NVIC_PRIO_BITS and FreeRTOS
configPRIO_BITS configuration macros such that these macros specify the
minimum number of implemented priority bits supported by a config
build rather than the exact number of implemented priority bits.

Related to Qemu issue #1122
2 years ago
Vo Trung Chi aa987a3443
fix conversion warning (#658)
FreeRTOS-Kernel/portable/GCC/ARM_CM4F/port.c:399:41: error: conversion from 'uint32_t' {aka 'long unsigned int'} to 'uint8_t' {aka 'unsigned char'} may change value [-Werror=conversion]

Signed-off-by: Vo Trung Chi <chi.votrung@vn.bosch.com>
2 years ago
kar-rahul-aws 99797e14e3
Cortex-M Assert when NVIC implements 8 PRIO bits (#639)
* Cortex-M Assert when NVIC implements 8 PRIO bits

* Fix CM3 ports

* Fix ARM_CM3_MPU

* Fix ARM CM3

* Fix ARM_CM4_MPU

* Fix ARM_CM4

* Fix GCC ARM_CM7

* Fix IAR ARM ports

* Uncrustify changes

* Fix MikroC_ARM_CM4F port

* Fix MikroC_ARM_CM4F port-(2)

* Fix RVDS ARM ports

* Revert changes for Tasking/ARM_CM4F port

* Revert changes for Tasking/ARM_CM4F port-(2)

* Update port.c

Fix GCC/ARM_CM4F port

* Update port.c

* update GCC\ARM_CM4F port

* update port.c

* Assert to check configMAX_SYSCALL_INTERRUPT_PRIORITY is set to higher priority

* Fix merge error: remove duplicate code

* Fix typos

---------

Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>
Co-authored-by: Ubuntu <ubuntu@ip-172-31-17-174.ec2.internal>
2 years ago
Paul Bartell 7b26ea6263
Enable building the GCC Cortex-R5 port without an FPU (#586)
* Ensure configUSE_TASK_FPU_SUPPORT option is set correctly

If one does enable the FPU of the Cortex-R5 processor, then the GCC
compiler will define the macro __ARM_FP. This can be used to ensure,
that the configUSE_TASK_FPU_SUPPORT is set accordingly.

* Enable the implementation of vPortTaskUsesFPU only if configUSE_TASK_FPU_SUPPORT is set to 1

* Remove error case in pxPortInitialiseStack

The case of configUSE_TASK_FPU_SUPPORT is 0 is now handled

* Enable access to FPU registers only if FPU is enabled

* Make minor formating changes

* Format ARM Cortex-R5 port

* Address review comments from @ChristosZosi

* Minor code review suggestions

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>

---------

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>
Co-authored-by: Christos Zosimidis <christos.zosimidis@gmail.com>
Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>
Co-authored-by: Gaurav Aggarwal <aggarg@amazon.com>
2 years ago
Chris Copeland a9e1f66849
Interrupt priority assert improvements for CM3/4/7 (#602)
* Interrupt priority assert improvements for CM3/4/7

In the ARM_CM3, ARM_CM4, and ARM_CM7 ports, change the assertion that
`configMAX_SYSCALL_INTERRUPT_PRIORITY` is nonzero to account for the
number of priority bits implemented by the hardware.

Change these ports to also use the lowest priority for PendSV and
SysTick, ignoring `configKERNEL_INTERRUPT_PRIORITY`.

* Remove not needed configKERNEL_INTERRUPT_PRIORITY define

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>

---------

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>
Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>
Co-authored-by: Gaurav Aggarwal <aggarg@amazon.com>
2 years ago
Devaraj Ranganna 5fdbb7fd2b
Cortex-M35P: Add Cortex-M35P port (#631)
* Cortex-M35P: Add Cortex-M35P port

The Cortex-M35P support added to kernel. The port hasn't been
validated yet with TF-M. Hence TF-M support is not included in this
port.

Signed-off-by: Devaraj Ranganna <devaraj.ranganna@arm.com>

* Add portNORETURN to the newly added portmacro.h

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>

---------

Signed-off-by: Devaraj Ranganna <devaraj.ranganna@arm.com>
Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>
Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>
Co-authored-by: Gaurav Aggarwal <aggarg@amazon.com>
Co-authored-by: kar-rahul-aws <118818625+kar-rahul-aws@users.noreply.github.com>
2 years ago
phelter 8cd5451ad5
Feature/fixing clang gnu compiler warnings (#620)
* Adding in ability to support a library for freertos_config and a custom freertos_kernel_port (#558)

* Using single name definition for libraries everywhere. (#558)

* Supporting backwards compatibility with FREERTOS_CONFIG_FILE_DIRECTORY (#571)

* Removing compiler warnings for GNU and Clang. (#571)

* Added in documentation on how to consume from a main project. Added default PORT selection for native POSIX and MINGW platforms.

* Only adding freertos_config if it exists. Removing auto generation of it from a FREERTOS_CONFIG_FILE_DIRECTORY.

* Fixing clang and gnu compiler warnings.

* Adding in project information and how to compile for GNU/clang

* Fixing compiler issue with unused variable - no need to declare variable.

* Adding in compile warnings for linux builds that kernel is okay with using.

* Fixing more extra-semi-stmt clang warnings.

* Moving definition of hooks into header files if features are enabled.

* Fixing formatting with uncrustify.

* Fixing merge conflicts with main merge.

* Fixing compiler errors due to merge issues and formatting.

* Fixing Line feeds.

* Adding 'portNORETURN' into portmacros.h. Other Updates based on PR request

* Further clean-up of clang and clang-tidy issues.

* Removing compiler specific pragmas from common c files.

* Fixing missing lexicon entry and uncrustify formatting changes.

* Resolving merge issue multiple defnitions of proto for prvIdleTask

* Fixing formatting issues that are not covered by uncrustify. Use clang-tidy instead if you want this level of control.

* More uncrustify formatting issues.

* Fixing extra bracket in #if statement.

---------

Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>
2 years ago
bbain 050cf0d80f
Introduce portMEMORY_BARRIER for Microblaze port. (#621)
The introduction of `portMEMORY_BARRIER` will ensure
the places in the kernel use a barrier will work.
For example, `xTaskResumeAll` has a memory barrier
to ensure its correctness when compiled with optimization
enabled. Without the barrier `xTaskResumeAll` can fail
(e.g. start reading and writing to address 0 and/or
infinite looping) when `xPendingReadyList` contains more
than one task to restore.

In `xTaskResumeAll` the compiler chooses to cache the
`pxTCB` the first time through the loop for use
in every subsequent loop. This is incorrect as the
removal of `pxTCB->xEventListItem` will actually
change the value of `pxTCB` if it was read again
at the top of the loop. The barrier forces the compiler
to read `pxTCB` again at the top of the loop.

The compiler is operating correctly. The removal
`pxTCB->xEventListItem` executes on a `List_t *`
and `ListItem_t *`.  This means that the compiler
can assume that any `MiniListItem_t` values are
unchanged by the loop (i.e. "strict-aliasing").
This allows the compiler to cache `pxTCB` as it
is obtained via a `MiniListItem_t`. This is incorrect
in this case because it is possible for a `ListItem_t *`
to actually alias a `MiniListItem_t`. This is technically
a "violation of aliasing rules" so we use the the barrier
to disable the strict-aliasing optimization in this loop.
2 years ago
Dusan Cervenka 91c20f5f42
Added support of 64bit events. (#597)
* Added support of 64bit even

Signed-off-by: Cervenka Dusan <cervenka@acrios.com>

* Added missing brackets

Signed-off-by: Cervenka Dusan <cervenka@acrios.com>

* Made proper name for tick macro.

Signed-off-by: Cervenka Dusan <cervenka@acrios.com>

* Improved macro evaluation

Signed-off-by: Cervenka Dusan <cervenka@acrios.com>

* Fixed missed port files  + documentation

Signed-off-by: Cervenka Dusan <cervenka@acrios.com>

* Changes made on PR

Signed-off-by: Cervenka Dusan <cervenka@acrios.com>

* Fix macro definition.

Signed-off-by: Cervenka Dusan <cervenka@acrios.com>

* Formatted code with uncrustify

Signed-off-by: Cervenka Dusan <cervenka@acrios.com>

---------

Signed-off-by: Cervenka Dusan <cervenka@acrios.com>
2 years ago
Paul Bartell 01820d3ed9 Normalize line endings and whitespace in source files 2 years ago
Kody Stribrny 1d59f65007
Add IAR RISC-V 32 Embedded Extension Support (#588)
Adds RV32E support to the IAR port. This is done by
reducing our register usage to the first 16 registers
only.

Influenced by changes in https://github.com/FreeRTOS/FreeRTOS-Kernel/pull/543

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>
Co-authored-by: Gaurav Aggarwal <aggarg@amazon.com>
2 years ago
ChristosZosi cd1f51cb5e
Add support for the configUSE_TASK_FPU_SUPPORT constant in the GCC/ARM_CR5 port (#584)
* Add support for the configUSE_TASK_FPU_SUPPORT in the GCC/ARM_CR5 port

This is done almost identically as in the GCC/ARM_CA9 port

* Adjust task stack initialitation of the GCC/ARM_CR5 port

Ensure that the task stack initialization is done correctly for the
different options of configUSE_TASK_FPU_SUPPORT.

This is very similar to the GCC/ARM_CA9 port. The only meaningful
difference is, that the FPU of the Cortex-R5 has just sixteen 64-bit
floating point registers as it implements the VFPv3-D16 architecture.
You may also refer to the ARM documentation

* Add support for FPU safe interrupts to the GCC/ARM_CR5 port

Similar to GCC/ARM_CA9 port

* Clarify comment about the size of the FPU registers of Cortex R5
2 years ago
Gaurav-Aggarwal-AWS 44e02bff31
Update Cortex-M55 and Cortex-M85 ports (#579)
These were missed when PR #59 was merged.

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>
2 years ago
RichardBarry d7b712668d
Update the NIOSII port to enable longer jumps (#578)
Update the NIOSII port so it works on systems with more RAM as
per https://forums.freertos.org/t/nios-ii-r-nios2-call26-noat-linker-error/16028
2 years ago
Jeff Tenney 195a351ec7
Tickless idle fixes/improvement (#59)
* Fix tickless idle when stopping systick on zero...

...and don't stop SysTick at all in the eAbortSleep case.

Prior to this commit, if vPortSuppressTicksAndSleep() happens to stop
the SysTick on zero, then after tickless idle ends, xTickCount advances
one full tick more than the time that actually elapsed as measured by
the SysTick.  See "bug 1" in this forum post:
https://forums.freertos.org/t/ultasknotifytake-timeout-accuracy/9629/40

SysTick
-------
The SysTick is the hardware timer that provides the OS tick interrupt
in the official ports for Cortex M.  SysTick starts counting down from
the value stored in its reload register.  When SysTick reaches zero, it
requests an interrupt.  On the next SysTick clock cycle, it loads the
counter again from the reload register.  To get periodic interrupts
every N SysTick clock cycles, the reload register must be N - 1.

Bug Example
-----------
- Idle task calls vPortSuppressTicksAndSleep(xExpectedIdleTime = 2).
  [Doesn't have to be "2" -- could be any number.]
- vPortSuppressTicksAndSleep() stops SysTick, and the current-count
  register happens to stop on zero.
- SysTick ISR executes, setting xPendedTicks = 1
- vPortSuppressTicksAndSleep() masks interrupts and calls
  eTaskConfirmSleepModeStatus() which confirms the sleep operation. ***
- vPortSuppressTicksAndSleep() configures SysTick for 1 full tick
  (xExpectedIdleTime - 1) plus the current-count register (which is 0)
- One tick period elapses in sleep.
- SysTick wakes CPU, ISR executes and increments xPendedTicks to 2.
- vPortSuppressTicksAndSleep() calls vTaskStepTick(1), then returns.
- Idle task resumes scheduler, which increments xTickCount twice (for
  xPendedTicks = 2)

In the end, two ticks elapsed as measured by SysTick, but the code
increments xTickCount three times.  The root cause is that the code
assumes the SysTick current-count register always contains the number of
SysTick counts remaining in the current tick period.  However, when the
current-count register is zero, there are ulTimerCountsForOneTick
counts remaining, not zero.  This error is not the kind of time slippage
normally associated with tickless idle.

*** Note that a recent commit https://github.com/FreeRTOS/FreeRTOS-Kernel/commit/e1b98f0
results in eAbortSleep in this case, due to xPendedTicks != 0.  That
commit does mostly resolve this bug without specifically mentioning
it, and without this commit.  But that resolution allows the code in
port.c not to directly address the special case of stopping SysTick on
zero in any code or comments.  That commit also generates additional
instances of eAbortSleep, and a second purpose of this commit is to
optimize how vPortSuppressTicksAndSleep() behaves for eAbortSleep, as
noted below.

This commit also includes an optimization to avoid stopping the SysTick
when eTaskConfirmSleepModeStatus() returns eAbortSleep.  This
optimization belongs with this fix because the method of handling the
SysTick being stopped on zero changes with this optimization.

* Fix imminent tick rescheduled after tickless idle

Prior to this commit, if something other than systick wakes the CPU from
tickless idle, vPortSuppressTicksAndSleep() might cause xTickCount to
increment once too many times.  See "bug 2" in this forum post:
https://forums.freertos.org/t/ultasknotifytake-timeout-accuracy/9629/40

SysTick
-------
The SysTick is the hardware timer that provides the OS tick interrupt
in the official ports for Cortex M.  SysTick starts counting down from
the value stored in its reload register.  When SysTick reaches zero, it
requests an interrupt.  On the next SysTick clock cycle, it loads the
counter again from the reload register.  To get periodic interrupts
every N SysTick clock cycles, the reload register must be N - 1.

Bug Example
-----------
- CPU is sleeping in vPortSuppressTicksAndSleep()
- Something other than the SysTick wakes the CPU.
- vPortSuppressTicksAndSleep() calculates the number of SysTick counts
  until the next tick.  The bug occurs only if this number is small.
- vPortSuppressTicksAndSleep() puts this small number into the SysTick
  reload register, and starts SysTick.
- vPortSuppressTicksAndSleep() calls vTaskStepTick()
- While vTaskStepTick() executes, the SysTick expires.  The ISR pends
  because interrupts are masked, and SysTick starts a 2nd period still
  based on the small number of counts in its reload register.  This 2nd
  period is undesirable and is likely to cause the error noted below.
- vPortSuppressTicksAndSleep() puts the normal tick duration into the
  SysTick's reload register.
- vPortSuppressTicksAndSleep() unmasks interrupts before the SysTick
  starts a new period based on the new value in the reload register.
  [This is a race condition that can go either way, but for the bug
  to occur, the race must play out this way.]
- The pending SysTick ISR executes and increments xPendedTicks.
- The SysTick expires again, finishing the second very small period, and
  starts a new period this time based on the full tick duration.
- The SysTick ISR increments xPendedTicks (or xTickCount) even though
  only a tiny fraction of a tick period has elapsed since the previous
  tick.

The bug occurs when *two* consecutive small periods of the SysTick are
both counted as ticks.  The root cause is a race caused by the small
SysTick period.  If vPortSuppressTicksAndSleep() unmasks interrupts
*after* the small period expires but *before* the SysTick starts a
period based on the full tick period, then two small periods are
counted as ticks when only one should be counted.

The end result is xTickCount advancing nearly one full tick more than
time actually elapsed as measured by the SysTick.  This is not the kind
of time slippage normally associated with tickless idle.

After this commit the code starts the SysTick and then immediately
modifies the reload register to ensure the very short cycle (if any) is
conducted only once.  This strategy requires special consideration for
the build option that configures SysTick to use a divided clock.  To
avoid waiting around for the SysTick to load value from the reload
register, the new code temporarily configures the SysTick to use the
undivided clock.  The resulting timing error is typical for tickless
idle.  The error (commonly known as drift or slippage in kernel time)
caused by this strategy is equivalent to one or two counts in
ulStoppedTimerCompensation.

This commit also updates comments and #define symbols related to the
SysTick clock option.  The SysTick can optionally be clocked by a
divided version of the CPU clock (commonly divide-by-8).  The new code
in this commit adjusts these comments and symbols to make them clearer
and more useful in configurations that use the divided clock.  The fix
made in this commit requires the use of these symbols, as noted in the
code comments.

* Fix tickless idle with alternate systick clocking

Prior to this commit, in configurations using the alternate SysTick
clocking, vPortSuppressTicksAndSleep() might cause xTickCount to jump
ahead as much as the entire expected idle time or fall behind as much
as one full tick compared to time as measured by the SysTick.

SysTick
-------
The SysTick is the hardware timer that provides the OS tick interrupt
in the official ports for Cortex M. SysTick starts counting down from
the value stored in its reload register. When SysTick reaches zero, it
requests an interrupt. On the next SysTick clock cycle, it loads the
counter again from the reload register. The SysTick has a configuration
option to be clocked by an alternate clock besides the core clock.
This alternate clock is MCU dependent.

Scenarios Fixed
---------------
The new code in this commit handles the following scenarios that were
not handled correctly prior to this commit.

1. Before the sleep, vPortSuppressTicksAndSleep() stops the SysTick on
zero, long after SysTick reached zero.  Prior to this commit, this
scenario caused xTickCount to jump ahead one full tick for the same
reason documented here: 0c7b04bd3a

2. After the sleep, vPortSuppressTicksAndSleep() stops the SysTick
before it loads the counter from the reload register.  Prior to this
commit, this scenario caused xTickCount to jump ahead by the entire
expected idle time (xExpectedIdleTime) because the current-count
register is zero before it loads from the reload register.

3. Prior to return, vPortSuppressTicksAndSleep() attempts to start a
short SysTick period when the current SysTick clock cycle has a lot of
time remaining.  Prior to this commit, this scenario could cause
xTickCount to fall behind by as much as nearly one full tick because the
short SysTick cycle never started.

Note that #3 is partially fixed by 967acc9b20
even though that commit addresses a different issue.  So this commit
completes the partial fix.

* Improve comments and name of preprocessor symbol

Add a note in the code comments that SysTick requests an interrupt when
decrementing from 1 to 0, so that's why stopping SysTick on zero is a
special case.  Readers might unknowingly assume that SysTick requests
an interrupt when wrapping from 0 back to the load-register value.

Reconsider new "_SETTING" suffix since "_CONFIG" suffix seems more
descriptive.  The code relies on *both* of these preprocessor symbols:

portNVIC_SYSTICK_CLK_BIT
portNVIC_SYSTICK_CLK_BIT_CONFIG  **new**

A meaningful suffix is really helpful to distinguish the two symbols.

* Revert introduction of 2nd name for NVIC register

When I added portNVIC_ICSR_REG I didn't realize there was already a
portNVIC_INT_CTRL_REG, which identifies the same register.  Not good
to have both.  Note that portNVIC_INT_CTRL_REG is defined in portmacro.h
and is already used in this file (port.c).

* Replicate to other Cortex M ports

Also set a new fiddle factor based on tests with a CM4F.  I used gcc,
optimizing at -O1.  Users can fine-tune as needed.

Also add configSYSTICK_CLOCK_HZ to the CM0 ports to be just like the
other Cortex M ports.  This change allowed uniformity in the default
tickless implementations across all Cortex M ports.  And CM0 is likely
to benefit from configSYSTICK_CLOCK_HZ, especially considering new CM0
devices with very fast CPU clock speeds.

* Revert changes to IAR-CM0-portmacro.h

portNVIC_INT_CTRL_REG was already defined in port.c.  No need to define
it in portmacro.h.

* Handle edge cases with slow SysTick clock

Co-authored-by: Cobus van Eeden <35851496+cobusve@users.noreply.github.com>
Co-authored-by: abhidixi11 <44424462+abhidixi11@users.noreply.github.com>
Co-authored-by: Joseph Julicher <jjulicher@mac.com>
Co-authored-by: alfred gedeon <28123637+alfred2g@users.noreply.github.com>
2 years ago
Cristian Cristea 24ade42a37
Added better pointer declaration readability (#567)
* Add better pointer declaration readability

I revised the declaration of single-line pointers by splitting it into
multiple lines. Now, every pointer is declared (and initialized
accordingly) on its own line. This refactoring should enhance
readability and decrease the probability of error when a new pointer is
added/removed or a current one has its initialization value modified.

Signed-off-by: Cristian Cristea <cristiancristea00@gmail.com>

* Remove unnecessary whitespace characters and lines

It removes whitespace characters at the end of lines (empty or
othwerwise) and clear lines at the end of the file (only one remains).
It is an automatic operation done by git.

Signed-off-by: Cristian Cristea <cristiancristea00@gmail.com>

Signed-off-by: Cristian Cristea <cristiancristea00@gmail.com>
2 years ago
Gaurav Aggarwal 79704b8213 Remove local stack variable form MPU wrappers
It was possible for a third party that had already independently gained
the ability to execute injected code to achieve further privilege
escalation by branching directly inside a FreeRTOS MPU API wrapper
function with a manually crafted stack frame. This commit removes the
local stack variable `xRunningPrivileged` so that a manually crafted
stack frame cannot be used for privilege escalation by branching
directly inside a FreeRTOS MPU API wrapper.

We thank Certibit Consulting, LLC, Huazhong University of Science and
Technology and the SecLab team at Northeastern University for reporting
this issue.

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>
2 years ago
Gaurav Aggarwal c2d616eaee Make RAM regions non-executable
This commit makes the privileged RAM and stack regions non-executable.

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>
2 years ago
Gaurav Aggarwal ea9c26f524 Use highest numbered MPU regions for kernel
ARMv7-M allows overlapping MPU regions. When 2 MPU regions overlap, the
MPU configuration of the higher numbered MPU region is applied. For
example, if a memory area is covered by 2 MPU regions 0 and 1, the
memory permissions for MPU region 1 are applied.

We use 5 MPU regions for kernel code and kernel data protections and
leave the remaining for the application writer. We were using lowest
numbered MPU regions (0-4) for kernel protections and leaving the
remaining for the application writer. The application writer could
configure those higher numbered MPU regions to override kernel
protections.

This commit changes the code to use highest numbered MPU regions for
kernel protections and leave the remaining for the application writer.
This ensures that the application writer cannot override kernel
protections.

We thank the SecLab team at Northeastern University for reporting this
issue.

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>
2 years ago
Gabor Toth 030e76681b
M85 support (#556)
* Extend support to Arm Cortex-M85

Signed-off-by: Gabor Toth <gabor.toth@arm.com>
Change-Id: I679ba8e193638126b683b651513f08df445f9fe6

* Add generated Cortex-M85 support files

Signed-off-by: Gabor Toth <gabor.toth@arm.com>
Change-Id: Ib329d88623c2936ffe3e9a24f5d6e07655e4e5c8

* Extend Trusted Firmware M port

Extend Trusted Firmware M port to Cortex-M23,
Cortex-M55 and Cortex-M85.

Signed-off-by: Gabor Toth <gabor.toth@arm.com>
Change-Id: If8f1081acfd04e547b3227579e70e355a6adffe3

* Re-run copy_files.py script

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>

Signed-off-by: Gabor Toth <gabor.toth@arm.com>
Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>
Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>
Co-authored-by: Gaurav Aggarwal <aggarg@amazon.com>
2 years ago
Jakub Lužný d91cd6fd05
RISC-V: Add support for RV32E extension in GCC port (#543)
Co-authored-by: Joseph Julicher <jjulicher@mac.com>
2 years ago
RichardBarry 8741c4f919
Include string.h at the top of portable/GCC/ARM_CA9/port.c to prevent memset() generating a warning. (#430)
Co-authored-by: none <unknown>
3 years ago
Gaurav-Aggarwal-AWS 3b18a07568
Add .syntax unified to GCC assembly functions (#538)
This fixes the compilation issue with XC32 compiler.

It was reported here - https://forums.freertos.org/t/xc32-v4-00-error-with-building-freertos-portasm-c/14357/4

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>

Co-authored-by: Paul Bartell <pbartell@amazon.com>
3 years ago
Gaurav-Aggarwal-AWS dc9c034c85
Add vPortRemoveInterruptHandler API (#533)
* Add xPortRemoveInterruptHandler API

This API is added to the MicroBlazeV9 port. It enables the application
writer to remove an interrupt handler.

This was originally contributed in this PR - https://github.com/FreeRTOS/FreeRTOS-Kernel/pull/523

* Change API signature to return void

This makes the API similar to vPortDisableInterrupt.

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>

Co-authored-by: Gavin Lambert <uecasm@users.noreply.github.com>
3 years ago
Gavin Lambert 63f86fc7a2
Implement MicroBlazeV9 stack protection (#523)
* Implement stack protection for MicroBlaze (without MPU wrappers)
3 years ago
Paul Bartell 2dfdfc4ba4
Add Cortex M7 r0p1 Errata 837070 workaround to CM4_MPU ports (#513)
* Clarify Cortex M7 r0p1 errata number in r0p1 specific port.

* Add ARM Cortex M7 r0p0 / r0p1 Errata 837070 workaround to CM4 MPU ports.

Optionally, enable the errata workaround by defining configTARGET_ARM_CM7_r0p0 or configTARGET_ARM_CM7_r0p1 in FreeRTOSConfig.h.

* Add r0p1 errata support to IAR port as well

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>

* Change macro name to configENABLE_ERRATA_837070_WORKAROUND

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>

Co-authored-by: Gaurav Aggarwal <aggarg@amazon.com>
3 years ago
alfred gedeon 719ceee352
Add suppport for ARM CM55 (#494)
* Add supposrt for ARM CM55

* Fix file header

* Remove duplicate code

* Refactor portmacro.h

1. portmacro.h is re-factored into 2 parts - portmacrocommon.h which is
   common to all ARMv8-M ports and portmacro.h which is different for
   different compiler and architecture. This enables us to provide
   Cortex-M55 ports without code duplication.
2. Update copy_files.py so that it copies Cortex-M55 ports correctly -
   all files except portmacro.h are used from Cortex-M33 ports.

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>

Co-authored-by: Gaurav Aggarwal <aggarg@amazon.com>
3 years ago
Gaurav-Aggarwal-AWS 40c37bd3ab
Add configSYSTICK_CLOCK_HZ to Cortex-M0 ports (#484)
This is needed to support the case when SysTick timer is not clocked
from the same source as CPU. This support already exists in other
Cortex-M ports.

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>
3 years ago
niniemann bdec3b6e54
fix: add additional .ltorg directives to GCC CM3/CM4 mpu ports (#473)
Co-authored-by: Nils Niemann <Niemann.N@eppendorf.de>
3 years ago
Ming Yue 09a2c0b324
Remove exception loop tags. (#457) 3 years ago