2015/06/28

DISCLAIMER: These notes are from the defunct k8 project which precedes SquirrelJME. The notes for SquirrelJME start on 2016/02/26! The k8 project was effectively a Java SE 8 operating system and as such all of the notes are in the context of that scope. That project is no longer my goal as SquirrelJME is the spiritual successor to it.

09:02

I am awake.

10:23

Although slightly "bad", I will not go through and check the times for a package over and over again. They will only be done once, so sources should not be changed during a build. Right now my build time is 24 seconds with nothing changed. Rebuilding hairball causes hairball-os-construct to rebuild which gives me 25 seconds to reach a TODO. And getting to the same spot gives me about 10 seconds to 12 seconds. So about twice as fast when the disk is not checked over and over.

16:47

Was doing real life stuff for many hours. Anyway, thought about how instructions will be encoded and decoded. Each instruction set will have fields that instructions use (like aa or i). Those fields will be an enumeration then there will be a stream-like way of initializing how instructions are encoded with bit fields and bit ranges and such. For instruction forms (such as on PowerPC and MIPS) there can just be macros which are predefined placement of said fields so they can just be set. I suppose a Function would work in the constructor so that there is not much of a body for instructions to use. Then there will be a generic opcode thing that can encode an instruction using arguments and such (EnumMap for that). I would like to keep the instruction list clean. So I can use method handles and use names and such for an emulator backend which can run any instruction and create SSA operations from that. At least for Java I can bring in a bunch of my NARF stuff to handle that. Each architecture however will require an encoder which takes SSA and turns it into binary code. Decoders and encoders would be optional but I would need a Java decoder and native CPU encoder. Later on I can reuse the system for a Java compiler and write a Java encoder.