jhhur@sorak.kaist.ac.kr (Jin Ho Hur) (03/18/88)
Our group are now evaluating Transputer and 80386 for our project of building a multiprocessor system for our project. There, one question arised and I found no answer from the Transputer architecture reference manual (RM) and the compiler writer's guide (CWG). Is there anybody out there who can answer to our questions? Our requirements: Basic unit of computation in our system is object which is comprised of an address space and a set of execution thread. We need the object to be dynnmically loadable and the execution threads (concurrent processes in T4/T8) to be created over those objects. In that regard, we appreciate the capability of Transputer to create a process very cheaply. But w.r.t. the program image loading, we want to that in run time, not just in reset or analyse time as is specified in RM. Our interpretation of Tranputer: There are two way to load program images on Transputer from our understanding of the RM and CWG: (1) Upon reset or analyse, the transputer is ready to accept the program image over any links. Based on the first byte, it loads the program on MemStart and jumps to it. (2) Upon analyse, one can peek/poke the memory of Transputer. Questions: (1) Should the program image be loaded a priori for a process on the image to be created? (2) Related to (1) above, is there any way to load a part of the program image upon demand? For it to be possible, there should be a mechamism to raise a trap upon invalid code address (a ka page fault) so that any pre-defined program be invoked to load the wanted part of the image. RM or CWG mentions nothing about that. (3) Or, is there a room for a MMU circuitary to be attached to the external memory interface of Transputer? (4) Is there any way to load the program image while the transputer is running? We may imaging the following scenario like we allocate a persistent process be running over each channel, define a protocol for it to recognize a program image loading phase, let it poke the remaining message to the specified location in the message, and create a process over the image. Is it the only way we can imagine? Please reply via mail. I will summarize the responses. JinHo Hur Dept of Computer Science, KAIST, Seoul, Korea UUCP: {mcvax,uunet}!sorak.kaist.ac.kr!jhhur Internet: jhhur%sorak.kaist.ac.kr@relay.cs.net EAN: jhhur@sorak.kaist.ac.kr