SquirrelJME/SquirrelJME

# 2015/11/02

***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._

## 00:55

Took a break playing some Doom 3.

## 11:12

Had a nightmare but nothing related to Doom 3. I got hacked.

## 11:20

One thing I can do is allow the stack offsets and such to use long instead of
int, in case for those really gigantic methods.

## 14:14

Compiled MMIX and MMIXX (a very basic display of running programs that write
to memory addresses but still print to the console). The MMIX instruction set
is rather interesting with 256 registers. However, the simulator is for
userland processes only. This means that there are more limitations has to
how programs are run. There is GIMMIX which does have a kernel mode and some
basic devices, will need to investigate that. It is reported that:

> By now, the simulator is finished and provides basic devices necessary for
> an operating system. These have been ported from the ECO32 project and
> include a disk, terminals, a timer, a ROM, a display and keyboard and an
> output device for debugging.

So using GIMMIX might be a better choice, if I manage to get it running. The
code is from 2011, I just hope it works on Big Endian systems such as my
PowerPC. Compiling it now it assumes that I am running x86 and passes the
command line argument to say to use a 387 FPU. And it appears it might just not
work at all. I could always compile it on a 386 and just use QEMU to emulate it
on this system.

## 14:36

There is also something called ECO32.

## 19:11

Want to add the operations for SPARC, however there is currently no easy to
parse table format (other than typing it manually). I e-mailed SPARC
International to see if they have something that is easy to parse. If I do not
get a response or they do not have such table, I will have to write a script
(in Java) that calls the SPARC disassembler much for many operations. Would
be slower as it is essentially just a brute force. I can probably run the
code on a fast system or multiple systems at once as needed.

Apart from that, the disparity between 32-bit and 64-bit when it comes to Java
can get slightly confusing.

I should probably get PowerPC working before I start doing other architectures
however.

## 21:42

I can most likely use the standard RISC generator for x86 although it would be
quite horrible due to the very limited nature of x86. You have the following:

 * EAX
 * EBX
 * ECX
 * EDX
 * ESI
 * EDI
 * EBP
 * EIP
 * ESP

Depends on if x86 supports instruction relative store/load as every other
RISC does.

## 21:58

Thinking about that, that would be very horrible. I would need to make a CISC
based version which can handle the very small amount of registers.

## 23:10

They are making a new Star Trek TV Series. One thing I would hope for that it
is the classic universe and not the rebooted movie stuff. The writers of the
new series made both of the new movies however. So there is a possibility that
it is the new universe.

## 23:50

Star Trek Continues is rather nice though. Watching Episode 5 I see that
technology has regressed a bit, the Enterprise computers have PCI and ISA
slots in the motherboards for their systems.