bluevm.asm

format elf64 executable 3

CELL_SIZE = 8

OPCODE_TBL_SIZE = 4096
INPUT_BUFFER_SIZE = 2048
RETURN_STACK_SIZE = 1024
DATA_STACK_SIZE = 1024
VM_ADDRS_SIZE = 64
CODE_BUFFER_SIZE = (4096 - VM_ADDRS_SIZE)

OPCODE_HANDLER_COMPILE = opcode_handler_compile
OPCODE_HANDLER_INTERPRET = opcode_handler_interpret
OPCODE_HANDLER_INVALID = _opcode_handler_invalid

OPCODE_ENTRY_FLAG_IMMEDIATE = 1 shl 0
OPCODE_ENTRY_FLAG_INLINED = 1 shl 1
OPCODE_ENTRY_FLAG_BYTECODE = 1 shl 2

segment readable writable executable

include "stack.inc"
include "interpreter.inc"

; expects status in edi
exit:
	mov	eax, 60

syscall_or_die:
	syscall
	
	test	rax, rax
	cmovs	edi, eax
	js	exit

	ret

init:
	mov	[instruction_pointer], input_buffer
	mov	[opcode_handler], OPCODE_HANDLER_INTERPRET
	mov	[opcode_handler_invalid], OPCODE_HANDLER_INVALID
	
	mov	[return_stack_here], return_stack
	mov	[return_stack_size], RETURN_STACK_SIZE
	mov	[data_stack_here], data_stack
	mov	[data_stack_size], DATA_STACK_SIZE

	mov	[vm_addr_opcode_handler_call], opcode_handler_call
	mov	[code_buffer_here], code_buffer
	mov	[code_buffer_size], CODE_BUFFER_SIZE
	
	ret
	
read_boot_code:
	mov	rsi, input_buffer
	mov	edx, INPUT_BUFFER_SIZE
	xor	edi, edi
	xor	eax, eax
	call	syscall_or_die

	test	eax, eax
	cmovz	edi, eax
	jz	exit
		
	ret

entry $
	call	init
	call	read_boot_code	
	call	interpreter

include "opcodes.inc"
rb (OPCODE_TBL_SIZE - ($ - opcode_tbl))

instruction_pointer rq 1
opcode_handler rq 1
opcode_handler_invalid rq 1

input_buffer rb INPUT_BUFFER_SIZE

return_stack rb RETURN_STACK_SIZE
return_stack_here rq 1
return_stack_size rq 1

data_stack rb DATA_STACK_SIZE
data_stack_here rq 1
data_stack_size rq 1

vm_addrs:
vm_addr_opcode_handler_call rq 1
rb (VM_ADDRS_SIZE - ($ - vm_addrs))

code_buffer rb (CODE_BUFFER_SIZE - VM_ADDRS_SIZE)
code_buffer_here rq 1
code_buffer_size rq 1