When implementing callbacks for Squeak in the "normal" Interpreter. I've implemented the callback processing loop as:

!ExternalInterface methodsFor: 'callBacks' !
interpretCallBack
	" Private - Interpret bytecodes while processing callback."
	self inline: false.
	waitingCallBack _ true.
	interpreterProxy internalizeIPandSP.
	[waitingCallBack] whileTrue: [
	  interpreterProxy interpretNextByteCode.
	].
	interpreterProxy externalizeIPandSP.
	waitingCallBack _ true.! !

And as an Interpreter instance method:
!Interpreter methodsFor: 'external calls' !
interpretNextByteCode
	"Advance the receiver and interpret the next byteCode."
	currentBytecode _ self fetchByte.
	self dispatchOn: currentBytecode in: BytecodeTable.!

now I want to port callbacks to the new Jitter Interpreter, but I don't know what to do to fetch a bytecode and dispatch it.
I have tried with:
!DynamicInterpreter methodsFor: 'external calls'! 
interpretNextByteCode
	"Advance the receiver and interpret the next byteCode."
	currentBytecode _ opcodeIndex.
	self dispatchOn: currentBytecode in: OpcodeTable.!
But it doesn't works.

What must I do to run the DynamicInterpreter loop until some condition?
(Remember that I am in a callback, similar to be inside a primitive)

Thanks,
Ale.