State of openjdk on hppa

[Andrew Haley]

On 01/05/2010 06:13 PM, Tom Rodriguez wrote:

>> openjdk builds on hppa, but doesn't run (yet). Andrew Haley once
>> debugged it and found out at least one things which would need to
>> be fixed: the assumption in the C++ interpreter that the stack
>> always grows downwards, and not upwards as on hppa.
>>
>> please could one of the hotspot developers sched some light on
>> this, how easy this might to be fix, and if there are other
>> assumptions?
> 
> Could you give more detail on where exactly the direction of growth
> is being assumed?  I know there's an accessor in frame that's
> supposed to describe the direction of growth of the expression stack
> which is used a few places in the code:
> 
>   // expression stack (may go up or down, direction == 1 or -1)
>  public:
>   intptr_t* interpreter_frame_expression_stack() const;
>   static  jint  interpreter_frame_expression_stack_direction();
> 
> I would think this has to be set correctly for HPPA to work.  Is it?
> It's possible that the C++ interpreter would also need to consult
> this when pushing values for it to work correctly.

I didn't get very far.  The first crash happens when the runtime
write-protects some of the stack pages, which immediately segfaults.

Andrew.