Commit Graph

1755 Commits

Author SHA1 Message Date
Ioannis Glaropoulos 9d8111c88f arch: arm: cortex-m: fix placement of ARMv7-M-related MPU workaround
The workaround for ARMv7-M architecture (which proactively
decreases the available thread stack by the size of the MPU
guard) needs to be placed before we calculate the pointer of
the user-space local thread data, otherwise this pointer will
fall beyond the boundary of the thread stack area.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-05-27 19:48:27 +02:00
Ioannis Glaropoulos 6b54958a0e arch: arm: aarch32: cortex-m: fix logic for detecting guard violation
We fix (by inverting) the logic of the IS_MPU_GUARD_VIOLATION
macro, with respect to the value of the supplied 'fault_addr'.
We shall only be inspecting the fault_addr value if it is not
set to -EINVAL.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-05-27 10:10:22 +02:00
Ioannis Glaropoulos 7284aee7d7 arch: arm: aarch32: cortex_m: add note in mem_manage_fault()
It is possible that MMFAR address is not written by the
Cortex-M core; this occurs when the stacking error is
not accompanied by a data access violation error (i.e.
when stack overflows due to the exception entry frame
stacking): z_check_thread_stack_fail() shall be able to
handle the case of 'mmfar' holding the -EINVAL value.

Add this node in mem_manage_fault() function to clarify
that it is valid for z_check_thread_stack_fail() to be
called with invalid mmfar address value.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-05-27 10:10:22 +02:00
Andrew Boie 2873afb7fe aarch32: fix a build failure
Some wires were crossed when an older PR was merged that
had build conflicts with newer code. Update this header
to reflect were the 'nested' member is in the kernel CPU
struct.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2020-05-08 13:59:17 -05:00
Andrew Boie a203d21962 kernel: remove legacy fields in _kernel
UP should just use _kernel.cpus[0].

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2020-05-08 17:42:49 +02:00
Stephanos Ioannidis aaf93205bb kconfig: Rename CONFIG_FP_SHARING to CONFIG_FPU_SHARING
This commit renames the Kconfig `FP_SHARING` symbol to `FPU_SHARING`,
since this symbol specifically refers to the hardware FPU sharing
support by means of FPU context preservation, and the "FP" prefix is
not fully descriptive of that; leaving room for ambiguity.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-05-08 10:58:33 +02:00
Abhishek Shah 2f85c01eaa arch: arm: aarch64: Add Cortex-A72 config
Add Cortex-A72 config in order to set "-mcpu" correctly.

Signed-off-by: Abhishek Shah <abhishek.shah@broadcom.com>
2020-05-08 10:46:23 +02:00
Stephanos Ioannidis 8b27d5c6b9 linker: Clean up section name definitions
This commit cleans up the section name definitions in the linker
sections header file (`include/linker/sections.h`) to have the uniform
format of `_(SECTION)_SECTION_NAME`.

In addition, the scope of the short section reference aliases (e.g.
`TEXT`, `DATA`, `BSS`) are now limited to the ASM code, as they are
currently used (and intended to be used) only by the ASM code to
specify the target section for functions and variables, and these short
names can cause name conflicts with the symbols used in the C code.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-04-30 13:42:36 -04:00
Sandeep Tripathy d4f1f2a07e arch: arm64: add public header for asm macros
Move generic macros to exported assembly header file
'macro.inc'. Rename the existing 'macro.inc' to 'macro_priv.inc'.

Signed-off-by: Sandeep Tripathy <sandeep.tripathy@broadcom.com>
2020-04-28 10:44:42 -07:00
Stephanos Ioannidis 0e6ede8929 kconfig: Rename CONFIG_FLOAT to CONFIG_FPU
This commit renames the Kconfig `FLOAT` symbol to `FPU`, since this
symbol only indicates that the hardware Floating Point Unit (FPU) is
used and does not imply and/or indicate the general availability of
toolchain-level floating point support (i.e. this symbol is not
selected when building for an FPU-less platform that supports floating
point operations through the toolchain-provided software floating point
library).

Moreover, given that the symbol that indicates the availability of FPU
is named `CPU_HAS_FPU`, it only makes sense to use "FPU" in the name of
the symbol that enables the FPU.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-04-27 19:03:44 +02:00
Andrew Boie 618426d6e7 kernel: add Z_STACK_PTR_ALIGN ARCH_STACK_PTR_ALIGN
This operation is formally defined as rounding down a potential
stack pointer value to meet CPU and ABI requirments.

This was previously defined ad-hoc as STACK_ROUND_DOWN().

A new architecture constant ARCH_STACK_PTR_ALIGN is added.
Z_STACK_PTR_ALIGN() is defined in terms of it. This used to
be inconsistently specified as STACK_ALIGN or STACK_PTR_ALIGN;
in the latter case, STACK_ALIGN meant something else, typically
a required alignment for the base of a stack buffer.

STACK_ROUND_UP() only used in practice by Risc-V, delete
elsewhere.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2020-04-21 18:45:45 -04:00
Andrew Boie 1f6f977f05 kernel: centralize new thread priority check
This was being done inconsistently in arch_new_thread(), just
move to the core kernel.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2020-04-21 18:45:45 -04:00
Andrew Boie c0df99cc77 kernel: reduce scope of z_new_thread_init()
The core kernel z_setup_new_thread() calls into arch_new_thread(),
which calls back into the core kernel via z_new_thread_init().

Move everything that doesn't have to be in z_new_thread_init() to
z_setup_new_thread() and convert to an inline function.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2020-04-21 18:45:45 -04:00
Stephanos Ioannidis ae427177c0 arch: arm: aarch32: Rework non-Cortex-M exception handling
This commit reworks the ARM AArch32 non-Cortex-M (i.e. Cortex-A and
Cortex-R) exception handling to establish the base exception handling
framework and support detailed exception information reporting.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-04-20 18:22:46 +02:00
Stephanos Ioannidis c442203c08 arch: arm: aarch32: Fix incorrect z_arm_{int,exc}_exit usage
In the ARM Cortex-M architecture implementation, the concepts of
"exceptions" and "interrupts" are interchangeable; whereas, in the
Cortex-A/-R architecture implementation, they are considered separate
and therefore handled differently (i.e. `z_arm_exc_exit` cannot be used
to exit an "interrupt").

This commit fixes all `z_arm_exc_exit` usages in the interrupt handlers
to use `z_arm_int_exit`.

NOTE: In terms of the ARM AArch32 Cortex-A and Cortex-R architecture
      implementations, the "exceptions" refer to the "Undefined
      Instruction (UNDEF)" and "Prefetch/Data Abort (PABT/DABT)"
      exceptions, while "interrupts" refer to the "Interrupt (IRQ)",
      "Fast Interrupt (FIQ)" and "Software Interrupt/Supervisor Call
      (SWI/SVC)".

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-04-20 18:22:46 +02:00
Stephanos Ioannidis b14d53435b arch: arm: aarch32: Split fault_s.S for Cortex-M and the rest
The exception/fault handling mechanisms for the ARM Cortex-M and the
rest (i.e. Cortex-A and Cortex-R) are significantly different and there
is no benefit in having the two implementations in the same file.

This commit relocates the Cortex-M fault handler to
`cortex_m/fault_s.S` and the Cortex-A/-R generic exception handler to
`cortex_a_r/exc.S` (note that the Cortex-A and Cortex-R architectures
do not provide direct fault vectors; instead, they provide the
exception vectors that can be used to handle faults).

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-04-20 18:22:46 +02:00
Stephanos Ioannidis 37f44193f3 arch: arm: aarch32: Split exc_exit.S for Cortex-M and the rest
The amount of shared code in exc_exit.S between the ARM Cortex-M and
the rest (i.e. Cortex-A and Cortex-R) is minimal and there is little
benefit in having the two implementations in the same file.

This commit splits the interrupt/exception exit code for the
Cortex-A/-R and Cortex-M into separate files to improve readability as
well as maintainability.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-04-20 18:22:46 +02:00
Sandeep Tripathy 1dc095c949 arch: arm64: use callee saved reg to stash
Use calee saved register to preserve value accoss sequence.
Procedure calls are mandated to follow ABI spec and preserve
x19 to x29.

Signed-off-by: Sandeep Tripathy <sandeep.tripathy@broadcom.com>
2020-04-20 16:14:36 +02:00
Sandeep Tripathy 82724de6a5 arch: arm64: refactor for EL3 specific init
Zephyr being an OS is typically expected to run at EL1. Arm core
can reset to EL3 which typically requires a firmware to run at EL3
and drop control to lower EL. In that case EL3 init is done by the
firmware allowing the lower EL software to have necessary control.

If Zephyr is entered at EL3 and it is desired to run at EL1, which
is indicated by 'CONFIG_SWITCH_TO_EL1', then Zephyr is responsible
for doing required EL3 initializations to allow lower EL necessary
control.

The entry sequence is modified to have control flow under single
'switch_el'.

Provisions added by giving weak funcions to do platform specific
init from EL3.

Signed-off-by: Sandeep Tripathy <sandeep.tripathy@broadcom.com>
2020-04-20 16:14:36 +02:00
Sandeep Tripathy c6f8771311 arch: arm64: macro for mov immediate
Single mov instruction can not be used to move non-zero
64b immediate value to the 64b register.
Implement macro to generate mov/ movk and movz sequences
depending on immediate value width.

Signed-off-by: Sandeep Tripathy <sandeep.tripathy@broadcom.com>
2020-04-20 16:14:36 +02:00
Kumar Gala 5648df39ac arch: arm: cortex_m: Rework DT_NUM_IRQ_PRIO_BITS
To remove the need to have DT_NUM_IRQ_PRIO_BITS defined in every
dts_fixup.h we can just handle the few variant cases in irq.h.  This
allows us to remove DT_NUM_MPU_REGIONS from all the dts_fixup.h files.

Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
2020-04-17 15:17:43 +02:00
Kumar Gala c5e5d531ca arch: arm: cortex_m: arm_mpu: Rework DT usage for DT_NUM_MPU_REGIONS
To remove the need to have DT_NUM_MPU_REGIONS defined in every
dts_fixup.h we can just handle the few variant cases in arm_mpu.c
directly.  This allows us to remove DT_NUM_MPU_REGIONS from all the
dts_fixup.h files.

Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
2020-04-17 15:17:43 +02:00
Stephanos Ioannidis 2d6194170b arch: arm: aarch32: Fix read_timer_end_of_isr register preservation
The current implementation to preserve r0 and r3 registers around the
call to `read_timer_end_of_isr` function has the following problems:

1. STM and LDM mnemonics are used without proper suffixes, in attempt
   to implement PUSH and POP (i.e. STMFD and LDMFD). The suffix-less
   STM mnemonic is equivalent to STMEA (increment after), which clearly
   is not a PUSH operation, and this corrupts the interrupt stack,
   leading to crashes on the Cortex-R.

2. The current implementation unnecessarily preserves additional r1, r2
   and lr registers. There is no need to preserve r1 and r2 because the
   values contained in these registers are not used after the function
   call; as for the lr register, it is already pushed to the stack when
   the interrupt service routine enters.

This commit removes all the unnecessary register preservations and
fixes the incorrect STM and LDM usages.

Note that the PUSH and POP aliases are used in place of the STMFD and
LDMFD mnemonics because they are used throughout the rest of the code.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-04-15 15:49:27 +02:00
Bobby Noelte 68cd1b7f9e arch: arm: aarch32: fix system clock driver selection for cortex m
The selection of the Cortex M systick driver to be used as a system
clock driver is controlled by CONFIG_CORTEX_M_SYSTICK.

To replace it by another driver CONFIG_CORTEX_M_SYSTICK must be set
to 'n'. Unfortunately this also controls the interrupt vector for
the systick interrupt. It is now routed to z_arm_exc_spurious.

Remove the dependecy on CONFIG_CORTEX_M_SYSTICK and route to
z_clock_isr as it was before #24012.

Fixes #24347

Signed-off-by: Bobby Noelte <b0661n0e17e@gmail.com>
2020-04-15 12:16:10 +02:00
Stephanos Ioannidis a1e838872c arch: arm: Remove extraneous root cmake files
The ARM architecture root directory contains `aarch32.cmake` and
`aarch64.cmake` files whose contents are better suited to go into other
more purpose-specific files.

This commit removes the aforementioned files and moves their contents
to other files following the convention used by other architectures.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-04-15 11:23:56 +02:00
Stephanos Ioannidis eeddc7566d arch: arm: aarch32: Add missing arch flag for Cortex-R5
This commit adds the GCC `-march` flag for the ARM Cortex-R5 targets.

Note that `armv7-r+idiv` must be specified instead of `armv7-r`,
because the GCC internally resolves `-mcpu=cortex-r5` to it.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-04-15 11:23:56 +02:00
Stephanos Ioannidis 3cf1a9139e arch: arm: Clean up configurations
This is a minor clean-up for the ARM architecture configurations.

Note that the `CPU_CORTEX_A` symbol is moved from the AArch64 to the
ARM root Kconfig because it can be selected from both AArch32 and
AArch64.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-04-15 11:23:56 +02:00
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
Ioannis Glaropoulos 95da5d479b arch: arm: minor fixes in the docs for ARM kernel_arch headers
Fix documentation in kernel_arch_data.h and kernel_arch_func.h
headers for ARM, to indicate that these are common headers for
all ARM architecture variants.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-04-09 13:13:42 -07:00
Ioannis Glaropoulos 25060b0f2e arch: arm: aarch32: rename z_arm_reserved to z_arm_exc_spurious
In the Cortex-M exception table we rename z_arm_reserved()
function to z_arm_exc_spurious(), as it is invoked when
existing (that is, non-reserved) but un-installed exceptions
are triggered, accidentaly, by software, or hardware. This
currently applies to SysTick and SecureFault exceptions.

Since fault.S is shared between Cortex-M and other AARCH32
architectures, we keep z_arm_reserved as a defined symbol
there. This commit does some additional, minor, "no-op"
cleanup in #ifdef's for Cortex-M and Cortex-R.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-04-07 09:57:12 -05:00
Ioannis Glaropoulos d3fa2eebb0 arch: arm: aarch32: cortex_m: add z_arm_reserved only if core has SE
If the Cortex-M core does not implement the Security Extension,
we should not be adding z_arm_reserved in the corresponding
vector table entry. That is because the entry is reserved by
the ARM architecture.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-04-07 09:57:12 -05:00
Ioannis Glaropoulos 4364f2d455 arch: arm: aarch32: add z_arm_reserved only when we have SysTick
If the Cortex-M core does not implement the SysTick peripheral,
we should not be adding z_arm_reserved in the corresponding
vector table entry. If we do have SysTick implemented but we
are not using it as the system timer, we shall install the
reserved interrupt at the vector table entry.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-04-07 09:57:12 -05:00
Ioannis Glaropoulos d725402daf arch: arm: aarch32: cortex_m: write 0x0 to reserved exception entries
Write 0x0 instead of z_arm_reserved to vector exception
entries that are always reserved for future use by the
ARM architecture. These vector table entries cannot be
fetched to be executed by the Cortex-M exception entry,
so having z_arm_reserved gives a false impression, since
it is a function that may be invoked in the code. This
modification is safe since these vector entries are also
not supposed to be read / written by the code.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-04-07 09:57:12 -05:00
Stephanos Ioannidis b63a028fbc arch: arm: aarch32: Rework non-Cortex-M context preservation
The current context preservation implementation saves the spsr and
lr_irq registers, which contain the cpsr and pc register values of the
interrupted context, in the thread callee-saved block and this prevents
nesting of interrupts because these values are required to be part of
the exception stack frame to preserve the nested interrupt context.

This commit reworks the AArch32 non-Cortex-M context preservation
implementation to save the spsr and lr_irq registers in the exception
stack frame to allow preservation of the nested interrupt context as
well as the interrupted thread context.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-04-02 09:22:38 +02:00
Carlo Caione 99a8155914 arm: AArch64: Add support for nested exception handlers
In the current implementation both SPSR and ELR registers are saved with
the callee-saved registers and restored by the context-switch routine.
To support nested IRQs we have to save those on the stack when entering
and exiting from an ISR.

Since the values are now carried on the stack we can now add those to
the ESF and the initial stack and take care to restore them for new
threads using the new thread wrapper routine.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
2020-03-31 19:24:48 +02:00
Stephanos Ioannidis 33928f18ae arch: arm: aarch32: Add header shims for `cortex_a_r` renaming
Out-of-tree code can still be using the old file locations. Introduce
header shims to include the headers from the new correct location and
print a warning message.

These shims should be removed after two releases.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-03-26 11:20:36 +01:00
Stephanos Ioannidis a033683783 arch: arm: aarch32: Rename `cortex_r` to `cortex_a_r`
This commit renames the `cortex_r` directory under the AArch32 to
`cortex_a_r`, in preparation for the AArch32 Cortex-A support.

The rationale for this renaming is that the Cortex-A and Cortex-R share
the same base design and the difference between them, other than the
MPU vs. MMU, is minimal.

Since most of the architecture port code and configurations will be
shared between the Cortex-A and Cortex-R architectures, it is
advantageous to have them together in the same directory.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-03-26 11:20:36 +01:00
Stephanos Ioannidis bafb623239 arch: arm: aarch32: Reorganise configurations
This commit re-organises AArch32 configurations for consistency.

1. Move Cortex-M-specific includes to `cortex_m/Kconfig`.

2. Relocate the "TrustZone" configurations to `cortex_m/tz/Kconfig`
  since these are really the TrustZone-M configurations and do not
  apply to the TrustZone-A.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-03-26 11:20:36 +01:00
Carlo Caione 67e4ccbc51 arch: aarch64: Add check on context switch
Check whether we actually need to schedule a new thread before calling
the context switch routine.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
2020-03-23 12:13:07 +01:00
Carlo Caione b41e5e67d0 arch: aarch64: Rewrite comments and rename swap routines
Rewrite the comments for the swap routine removing the references to the
old aarch32 code and rename z_arm64_pendsv() ->
z_arm64_context_switch().

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
2020-03-23 12:13:07 +01:00
Carlo Caione fbf9b2675d aarch64: swap: Remove redundant code
Delete redundant / useless code from z_arm64_pendsv().

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
2020-03-23 12:13:07 +01:00
Carlo Caione 99e63a799d arch: aarch64: Rework exception entry/exit code
Rework the assembly code for the ISR wrapper and SVC to share the
entry/exit code that is currently scattered amoung several files /
places. No functional changes.

Rename also macro.h -> macro.inc to fool the CI.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
2020-03-20 14:15:43 +01:00
Ioannis Glaropoulos fec399e74a arch: arm: aarch32: correct documentation of arch_cpu_atomic_idle
z_CpuIdleInit has been renamed to z_arm_cpu_idle_init, so
we need to correct that function's name in the documentation
of arch_cpu_atomic_idle.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-03-20 11:53:14 +01:00
Stephanos Ioannidis 3f395f5698 arch: arm: aarch32: Add memory barriers to arch_cpu_idle
This commit adds the required memory barriers to the `arch_cpu_idle`
function in order to ensure proper idle operation in all cases.

1. Add ISB after setting BASEPRI to ensure that the new wake-up
  interrupt priority is visible to the WFI instruction.

2. Add DSB before WFI to ensure that all memory transactions are
  completed before going to sleep.

3. Add ISB after CPSIE to ensure that the pending wake-up interrupt
  is serviced immediately.

Co-authored-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-03-20 11:53:14 +01:00
Stephanos Ioannidis ba0bcaf41b arch: arm: aarch32: Fix arch_cpu_idle interrupt masking
The current AArch32 `arch_cpu_idle` implementation enables interrupt
before executing the WFI instruction, and this has the side effect of
allowing interruption and thereby calling wake-up notification
functions before the CPU enters sleep.

This commit fixes the problem described above by ensuring that
interrupt is disabled when the WFI instruction is executed and
re-enabled only after the processor wakes up.

For ARMv6-M, ARMv8-M Baseline and ARM-R, the PRIMASK (ARM-M)/
CPSR.I (ARM-R) is used to lock interrupts and therefore it is not
necessary to do anything before executing the WFI instruction.

For ARMv7-M and ARMv8-M Mainline, the BASEPRI is used to lock
interrupts and the PRIMASK is always cleared in non-interrupt context;
therefore, it is necessary to set the PRIMASK to mask interrupts,
before clearing the BASEPRI to configure wake-up interrupt priority to
the lowest.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-03-20 11:53:14 +01:00
Stephanos Ioannidis 50e4f2a671 arch: arm: aarch32: Fix whitespaces in cpu_idle.S
This commit fixes whitespaces in cpu_idle.S.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-03-20 11:53:14 +01:00
Andrew Boie 28be793cb6 kernel: delete separate logic for priv stacks
This never needed to be put in a separate gperf table.
Privilege mode stacks can be generated by the main
gen_kobject_list.py logic, which we do here.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2020-03-17 20:11:27 +02:00
Øyvind Rønningstad c3ee533b5e arch: arm: tz: secure_entry_functions: Add support for nRF53
The nRF53 has different region size than nRF91.
This patch is aware of Erratum 19 (wrong SPU region size).

Signed-off-by: Øyvind Rønningstad <oyvind.ronningstad@nordicsemi.no>
2020-03-17 11:41:19 +01:00
Andrew Boie 80a0d9d16b kernel: interrupt/idle stacks/threads as array
The set of interrupt stacks is now expressed as an array. We
also define the idle threads and their associated stacks this
way. This allows for iteration in cases where we have multiple
CPUs.

There is now a centralized declaration in kernel_internal.h.

On uniprocessor systems, z_interrupt_stacks has one element
and can be used in the same way as _interrupt_stack.

The IRQ stack for CPU 0 is now set in init.c instead of in
arch code.

The extern definition of the main thread stack is now removed,
this doesn't need to be in a header.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2020-03-16 23:17:36 +02:00
Stephanos Ioannidis cd90d49a86 arch: arm: Optimise Cortex-R exception return function.
z_arm_exc_exit (z_arm_int_exit) requires the current execution mode to
be specified as a parameter (through r0). This is not necessary because
this value can be directly read from CPSR.

This commit modifies the exception return function to retrieve the
current execution mode from CPSR and removes all provisions for passing
the execution mode parameter.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-03-14 11:49:22 +01:00