[nergal]

https://bitbucket.org/assyrian/tf2-building-vm/src/

Hello to whoever reads this, I'm making a stack-based VM straight in sourcepawn.

The entire purpose of this plugin is to create programmable engineer buildings for TF2 where knowledgeable or interested players could make their buildings do more than what they currently do.

the Current Opcode list is...

PHP Code:

load - loads a constant into memory
add - adds two stack items
sub - subs two stack items
mul - multiplies two stack items
div - divides two stack items
jmp - jumps to a portion of the instruction list
print - prints the data at the current stack pointer
pop - removes the first data at the stack pointer
inc - increments an item in memory
dec - decrements an item in memory
brt - same as jmp but conditional if the stack item is true
brf - same as brt but branches if the stack item is false
eq - checks if two stack items are equal
less - checks if the secondary stack item is less than the first stack item
great - checks if the secondary stack item is greater than the first stack item
AND - does bitwise AND operation between two stack items
OR - does bitwise OR operation between two stack items
XOR - does bitwise XOR operation between two stack items
NOT - does bitwise complement operation on the first stack item the stack pointer lists 


what I would hope to do in the future is to define variables/identifiers as well as do a call stack so I can implement subroutines!

[Potato Uno]

So... a VM on top of another VM?

[nergal]

Originally Posted by Potato Uno So... a VM on top of another VM?

yes lmao. Also why not?

[nergal]

I forgot that there's a Stack datatype in the sourcemod lib which I should probably use to replace the stack in this MetaVM. I should also add registers to this VM and use the stack for function calls.

[nergal]

there we go, upgraded the whole plugin to use data structures!

I used stringmap to make an opcode table, used the arraylist struct to hold all the tokens for the instruction set, and used arraystack to replace the int array stack.

https://bitbucket.org/assyrian/tf2-b...ng/?at=default

[Chief149]

You should make this VM capable of running Windows. Then put Windows on it, and then load a source engine game on THAT.

Great way to make the universe implode on itself.

[thecount]

Originally Posted by Chief149 You should make this VM capable of running Windows. Then put Windows on it, and then load a source engine game on THAT.

And then run the VM on the VM's own source engine. Just in case.

[nergal]

Originally Posted by Chief149 You should make this VM capable of running Windows. Then put Windows on it, and then load a source engine game on THAT. Great way to make the universe implode on itself.

lol the whole point of this was to make programmable sentry guns xD

I mean, how else can u make the engineer buildings do custom things?

[nergal]

new update to this thing!

I changed the instructions to be a little bit more similar to x86 for familiarity.

I made a cheap little tokenizer to actually split up text in a way that you can format better and still have it.

the tokenizer can even tokenize the 0x0 style Hexadecimal values.

tokenizer ignores spaces, tabs, commas, new lines, and carriage return.

most importantly, this VM isn't just a stack machine either, it has both a useable stack and 8 registers

the new instruction set is...

PHP Code:

"halt"
"mov"
"push"
"pop"
"add"
"sub"
"mul"
"div"
"inc"
"dec"
"neg"
"and"
"or"
"xor"
"not"
"jmp"
"call"
"ret"
    
"grt"
"less"
"eql"
"grteq"
"lesseq" 


The useable register's are.

PHP Code:

// Set registers
"eax"
"ebx"
"ecx"
"edx"
"esi"
"edi"
"ebp"
"esp" // when increment the stack, this increases by 4. decreases everytime you pop the stack. 


example code

PHP Code:

mov eax 10, dec eax, grt eax 0 3, halt 


C equivalent code

PHP Code:

int i=10;
--i;
while (i > 0)
   --i; 


try it out!

https://bitbucket.org/assyrian/tf2-building-vm/src/