abort and resume, assembler

[sachin thakur]

Hi,

Thanks for your inputs..

I have one more querry...

1.         I am trying to implement abort and resume (section 7.6.3). After reading the spec my understanding is that when a abort key sequence is pressed the currently running program should halt and control should transfer to the command interpreter.

But the openfirmware process model is single-threaded and there is only one, non-preempted program running at a time. So when a program is running how can i detect the abort key sequence?

2.         I am trying to implement forth word for the Assembler mentioned In Open Firmware spec., section 7.3.9.3.

According to this section user should be able to create machine-level code definition from the command interpreter.

My doubt is how forth inner-interpreter will identify the machine dependent assembly mnemonics?

Whether Assembler would be invoked to parse the machine level code entered from the command interpreter?

In this case, Assembler should be the part of the boot firmware?

Regards

Sachin

-----Original Message-----
From: Stefan Reinauer [mailto:[e-mail]] 
Sent: Thursday, March 17, 2005 8:05 PM
To: The OpenBIOS Mailinglist
Subject: Re: [OpenBIOS] cpeek, wpeek etc

* sachin thakur  [050317 08:36]:
> Hi all
>
> I am trying to implement the words mentioned in section 5.3.7.1 of 
> open firmware specification viz. cpeek, wpeek etc.
>
> For this I have already implemented exception handling, which is in C 
> and assembly.

Sounds interesting. Did you have a look at the exception handling code I checked in a while ago?
> Now to implement these words I need to create some flags (variables) 
> which can be accessed from both forth and C.
>
> Is there any way by which I can access the same variable from both c 
> and forth.

Yes, look at the handling of "last". Variables in forth are just normal words that push the address of the memory associated with them to the stack. You can use this with the normal forth-c-bindings

If you publish a patch of your work people here can likely help you.