A race condition is present where an IRQ is serviced between the
priority increase of the PENDSV and the sleep. When the IRQ
is serviced before the WFI sleep, the core will sleep until the next
IRQ and the thread activated by the IRQ will not be scheduled until
a new IRQ triggers.
This commit wraps an IRQ disable and restore around the priority
modification and sleep to prevent interrupts from being serviced until
the WFI call returns.
The `ldr r1, =sched_active_thread` instruction couldn't be assembled with
LTO, as the no immediate offset could be found to construct the address of
`sched_active_thread`. This commit instructs the assembler to generate a
literate pool which can be used to construct the address. While this issue
was only triggered during LTO, it theoretically could also pop up without LTO
due to unrelated changes. Thus, it is a good idea to create the literate pool
even without LTO enabled.
- Use `irq_enable()` over `bl irq_enable`, as `irq_enable()` is an inline
function and not a C function any more
- Drop `__attribute__((naked))` qualifier
- It must be used with the declaration of the function, but there it is
missing. (And it cannot be added there, as this function would need to
be implemented as "naked" by every platform; which is impossible for
platforms not supporting `__attribute__((naked))`.)
- Only functions consisting completely of basic asm may be marked as naked.
But both the assembly used to trigger the SVC interrupt as well as the
assembly used in `irq_enable()` are extended asm, not basic asm
- Use ` UNREACHABLE();` over a custom asm construct
All bits in the ICSR register in the cortexm system control block are
either read-only or don't have an effect when writing a zero. A
read-modify-write cycle is thus not required when writing bit flags in
the register. This commit removes the reads in the read-modify-store
patterns for this register.
Refactor and add multiply by word size to get the usage in number of
bytes instead of in number of words.
Verified implementation by manual memory inspection in GDB.
- removed coretx-m[0|3|4]
- moved their content to cortexm_common
- adjusted cortex Makefiles to this new name
- adjusted cortex Makefiles new structure
- fixes to cortexm-common
- Added ARM CMSIS headers to cortexm_common
- thread_exit fixes to cortexm-common
- cortexm-common adjusted documentation
- cortexm_common added eINT dINT defines for now
