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A project log for F-CPU

The Freedom CPU project has a log here too now :-)

Yann Guidon / YGDESYann Guidon / YGDES 03/07/2018 at 08:220 Comments

I think I'm closer to the solution of the old old problem of copy-less data transmission between threads or processes.

Already, switching from one process to another is almost as easy as a Call/Return within a given process. The procedure uses 3 dedicated opcodes : IPC, IPE and IPR (InterProcess Call/Enter/Return). The real problem is how to transfer more data than what the register set can hold.

My new solution is to "mark" certain address registers to yield the ownership of the pointer to the called process.

This creates quite a lot of new sub-problems but I believe it is promising.

This affects the paging system in many ways so this will be the next thing to study...