Commit graph

5896 commits

Author SHA1 Message Date
Wayne Ren
e43e137d8b arch: arc: remove MPU_STACK_GUARD for ARC_MPU_VER 2
ARC_MPU_VER 2 has a strong requirement in
  * size, must be >= 2048 bytes and power of 2
  * start address must be aligned to size

It may bring a big waste of memory.

On the other hand, GEN_PRIV_STACK is used for ARC_MPU_VER 2,
it conflicts with MPU_STACK_GUARD.

So considering the limmitations, remove MPU_STACK_GUARD for
ARC_MPU_VER 2

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2020-05-06 12:51:05 -07:00
Wayne Ren
7633da7046 arch: arc: ARC MPUv3 doesn't use GEN_PRIV_STACK
Because ARC MPUv3 doesn't have a strong alignment requirement
as ARC MPUv2 does, no use of GEN_PRIV_STACK for it.

Without GEN_PRIV_STACK, all stack elements can be in one stack object.
See #24048.

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2020-05-06 12:51:05 -07:00
Wayne Ren
99dd392825 arch: arc: use the way of GEN_PRIV_STACK for privilege stack
drop the original C macro based allocation of privilged stack as
it may cause the waste of memory for ARC MPUv2.

now use the way of GEN_PRIV_STACK to generate privilege stack as
other archs did, e.g. ARM.

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2020-05-06 12:51:05 -07:00
Andrew Boie
0091a700d3 x86_64: fix crash on nested interrupts
x86_64 supports 4 levels of interrupt nesting, with
the interrupt stack divided up into sub-stacks for
each nesting level.

Unfortunately, the initial interrupt stack pointer
on the first CPU was not taking into account reserved
space for guard areas, causing a stack overflow exception
when attempting to use the last interrupt nesting level,
as that page had been set up as a stack guard.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2020-05-01 11:44:05 -07:00
Andrew Boie
dac61f450d x86: fix trampoline stack clobber
We need to lock interrupts before setting the thread's
stack pointer to the trampoline stack. Otherwise, we
could unexpectedly take an interrupt on this stack
instead of the thread stack as intended.

The specific problem happens at the end of the interrupt,
when we switch back to the thread stack and call swap.
Doing this on a per-cpu trampoline stack instead of the
thread stack causes data corruption.

Fixes: #24869

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2020-05-01 11:43:57 -07:00
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
Kumar Gala
a45ea3806f x86: Rework rework x86 related code to use new DTS macros
Replace DT_PHYS_RAM_ADDR and DT_RAM_SIZE with DT_REG_ADDR/DT_REG_SIZE
for the DT_CHOSEN(zephyr_sram) node.

Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
2020-04-30 08:37:18 -05:00
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
Tobias Svehagen
ca872a44c1 lib: posix: Add support for eventfd
This implements a file descriptor used for event notification that
behaves like the eventfd in Linux.

The eventfd supports nonblocking operation by setting the EFD_NONBLOCK
flag and semaphore operation by settings the EFD_SEMAPHORE flag.

The major use case for this is when using poll() and the sockets that
you poll are dynamic. When a new socket needs to be added to the poll,
there must be some way to wake the thread and update the pollfds before
calling poll again. One way to solve it is to have a timeout set in the
poll call and only update the pollfds during a timeout but that is not
a very nice solution. By instead including an eventfd in the pollfds,
it is possible to wake the polling thread by simply writing to the
eventfd.

Signed-off-by: Tobias Svehagen <tobias.svehagen@gmail.com>
2020-04-28 09:57:41 +03:00
Stephanos Ioannidis
4f4e85c035 kconfig: Improve architecture floating point symbol descriptions
This commit reworks the symbol descriptions for `CONFIG_FPU` and
`CONFIG_FP_SHARING`, in order to provide more details and clarify any
ambiguity between the two symbols.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-04-27 19:03:44 +02:00
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
Corey Wharton
6f6564752a riscv: Restore floating-point caller saved registers before integer
This fixes an issue where the t0 register is overwritten after it
has been restored.

Signed-off-by: Corey Wharton <coreyw7@fb.com>
2020-04-22 16:39:48 -07:00
Corey Wharton
c8f7cd5462 kconfig: Make the CPU_HAS_FPU_DOUBLE_PRECISION option global.
This option now applies to the RISC-V architecture and is no longer
a ARM only configuration.

Signed-off-by: Corey Wharton <coreyw7@fb.com>
2020-04-22 16:39:48 -07:00
Corey Wharton
22c52846a5 riscv: Set mabi and march flags for floating point
Adds handling of the FLOAT_64BIT option when determining the ISA
flags as well as introduces a new Kconfig option to enable/disable
the hard-float calling convention.

Signed-off-by: Corey Wharton <coreyw7@fb.com>
2020-04-22 16:39:48 -07:00
Corey Wharton
58232d58e0 riscv: Add support for floating point
This change adds full shared floating point support for the RISCV
architecture with minimal impact on threads with floating point
support not enabled.

Signed-off-by: Corey Wharton <coreyw7@fb.com>
2020-04-22 16:39:48 -07:00
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
Martí Bolívar
6d0896b7ec gen_isr_tables: error improvements
Random readability improvements:

- avoid a stack trace on error by using sys.exit()
- include "error:" in the error() output, for grep
- print conflicting addresses on multiple IRQ registration

Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>
2020-04-17 18:28:47 +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
Stephanos Ioannidis
cdbfbe396f tests: benchmarks: Fix incorrect ARM arch variant check
Currently, the Cortex-M SysTick-based timing info implementation is
incorrectly specified for all 32-bit ARM architectures.

This commit fixes that by restricting the SysTick-based implementation
to the ARM Cortex-M architectures only; in addition, it removes the
ARM64 timing info implementation as it is identical to the default
generic implementation and was previously added only as a workaround
for the aforementioned problem.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-04-15 15:49:27 +02:00
Stephanos Ioannidis
819fe00071 tests: benchmarks: Fix Kconfig symbol checks
This commit fixes the incorrect (or un-conventional, at least) Kconfig
boolean symbol checks.

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
Wayne Ren
2833d016aa arch: arc: fix the bug of IRQ_ACT.U bit sync up
This bug is brought in commit 3f88ddd54999.

The cleanup of IRQ_ACT.U bit before thread switch is not done.

The bug comes out at the case where interrupt comes in user mode,
then a thread switch happens, and the target thread is to run in kernel
mode. Because the U bit is not sync up correctly, the stack operation
is wrong.

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2020-04-14 12:52:41 -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
Kumar Gala
a5cd799523 arch: riscv: irq: fix build warning
In arch_irq_connect_dynamic the 'level' variable is only used on
platforms that define CONFIG_RISCV_HAS_PLIC.  For the other platforms
we'll get a warning about an unused variable.  Remove the need for
'level' and just call irq_get_level() where its needed to address the
issue.

Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
2020-04-10 12:38:06 -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
Jaron Kelleher
0fb4382164 arch: isr: Update z_isr_install for multi-level interrupts
z_isr_install is not suited to handle multi-level interrupt formats.
This update allows z_isr_install to accept irq numbers in zephyr format
and place them in the isr table appropriately.

Fixes issue #22145

Signed-off-by: Jaron Kelleher <jkelleher@fb.com>
2020-04-09 13:12:24 -07:00
Daniel Leung
7b31f93980 xtensa: enable XTENSA_HAL at SoC level
This moves enabling XTENSA_HAL to the SoC definitions.
As Xtensa SoCs are highly configurable, it is possible
that the generic Xtensa HAL provided in the tree is
not suitable. So only enable XTENSA_HAL only if
the generic version can be used.

Signed-off-by: Daniel Leung <daniel.leung@intel.com>
2020-04-08 13:10:35 -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
Jaron Kelleher
bd4f721a59 RISCV compiler: Set mabi and march via Kconfig options
The mabi and march options of the compiler and linker commands
were previously hardcoded and depended only on the 64BIT config
option. This update allows these flags to be set by the config
options currently available, plus an additional option to
specify the compressed ISA.

Signed-off-by: Jaron Kelleher <jkelleher@fb.com>
2020-04-06 21:54:07 -04:00
Wayne Ren
819e7aec77 arch: arc: optimizations on irq lock/unlock in low level
When SMP is enabled, the irq_lock/unlock will get and
release a global spin lock, but the codes changed in this
commit only need to lock the local cpu. No affect on
uniprocessor, but optimizations for SMP case.

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2020-04-06 11:17:38 -07:00
Wayne Ren
8f76233029 arch: arc: optimize the arc v2 interrupt unit driver
* add interrupt lock in low level API to gurantee the
  correctness of operations.

* make some functions as in-line functions

* clean up and optimize the code comments

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2020-04-06 11:17:38 -07:00
Kumar Gala
cd88902bc4 arch: posix: Kconfig: select HAS_DTS as the arch level
Now that all posix boards have a dts we can move the selection of
HAS_DTS to the arch level like it is for all the other architectures.

Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
2020-04-04 16:01:11 +02:00
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