Instead of having some special stack frame when first scheduling new
thread and a new thread entry wrapper to pull out the needed data, we
can reuse the context restore code by adapting the initial stack frame.
This reduces the lines of code and simplify the code at the expense of a
slightly bigger initial stack frame.
Signed-off-by: Carlo Caione <ccaione@baylibre.com>
Switch to the _arch_switch() API that is required for an SMP-aware
scheduler instead of using the old arch_swap mechanism.
SMP is not supported yet but this is a necessary step in that direction.
Signed-off-by: Carlo Caione <ccaione@baylibre.com>
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>
Introduce the basic ARM64 architecture support.
A new CONFIG_ARM64 symbol is introduced for the new architecture and new
cmake / Kconfig files are added to switch between ARM and ARM64.
Signed-off-by: Carlo Caione <ccaione@baylibre.com>
