[PATCH v1 3/5] cpukit/microblaze: Add interrupt hooks

[Kinsey Moore]

On 2/17/2022 13:53, Chris Johns wrote:
> On 16/2/22 7:38 am, Kinsey Moore wrote:
>> Add hooks for manipulating system state before and after interrupts are
>> run. These hooks serve primarily to allow the MicroBlaze libdebugger
>> backend to prevent software breaks from occurring in interrupt context.
> I am unsure what problem this is resolving?
This is resolving an issue specific to libdebugger backends that use 
only software breaks without any additional architecture support. When 
entering interrupt context, breakpoints of all varieties must be 
disabled or libdebugger may be called into from interrupt context which 
libdebugger ignores as something that needs to be passed to the fatal 
error handler. Microblaze in particular has no way to set hardware 
breakpoints, watchpoints, or single-step operation from the CPU (even if 
they exist in some configurations) and no way to disable software breaks 
upon entry to interrupt context without hooks of this variety.
> Who is setting breaks points in interrupts?

Where I encountered issues was setting breaks in library functions that 
I was stepping through in non-interrupt context, particularly in 
memset(). ISR handlers can also call into this library code and 
libdebugger bails when application debugging intersects with ISR handler 
execution.


Kinsey