SPARC: Keep interrupts disabled during kernel init
This commit avoids enabling interrupts during Zephyr init.
Details:
Interrupts will be enabled only when the first thread starts or if
arch_irq_unlock() is called before that.
The logic is now:
1. Enable traps, disable interrupts globally
2. Initialize bss
3. Call _PrepC
Use in-place memset() to avoid register window overflow and underflow
traps. That is perhaps not the common scenario, but could happen with
memset() implementation which contains SAVE instructions on a system
with few register windows.
The second, and more important, item this commit addresses is that it
increases the processor interrupt level (priority) to highest. That
is, it enters _PrepC with all maskable interrupts levels disabled.
This fixes some cases where interrupts could be taken after
z_clock_driver_init() while the system was still initializing. That
seem to have occurred when clearing large thread stacks.
The third thing is that we now start out with current window pointer
0 (PSR.CWP=0) instead of 1. It has no practical implication except
for preparing for possible future support for systems with only
two windows.
Signed-off-by: Martin Åberg <martin.aberg@gaisler.com>
1 file changed
