rubyx/lib/register/builtin/kernel.rb
Torsten Ruger ef6cb2a069 use instruction steam from message
had been attached there last week, but was still used mainly through
the source (which i’m trying to remove)
2015-10-28 14:33:38 +02:00

68 lines
2.9 KiB
Ruby

module Register
module Builtin
module Kernel
module ClassMethods
# this is the really really first place the machine starts (apart from the jump here)
# it isn't really a function, ie it is jumped to (not called), exits and may not return
# so it is responsible for initial setup
def __init__ context
function = MethodSource.create_method(:Kernel,:__init__ , [])
# no method enter or return (automatically added), remove
new_start = Label.new(function , "__init__" )
function.instructions = new_start
function.source.current = new_start
#Set up the Space as self upon init
space = Parfait::Space.object_space
space_reg = Register.tmp_reg(:Space)
function.source.add_code LoadConstant.new(function, space , space_reg)
message_ind = Register.resolve_index( :space , :first_message )
# Load the message to new message register (r1)
function.source.add_code Register.get_slot( function , space_reg , message_ind , :new_message)
# And store the space as the new self (so the call can move it back as self)
function.source.add_code Register.set_slot( function, space_reg , :new_message , :receiver)
# now we are set up to issue a call to the main
Register.issue_call( function , Register.machine.space.get_main)
emit_syscall( function , :exit )
return function
end
def exit context
function = MethodSource.create_method(:Kernel,:exit , [])
return function
ret = RegisterMachine.instance.exit(function)
function.set_return ret
function
end
def emit_syscall function , name
save_message( function )
function.source.add_code Syscall.new(function, name )
restore_message(function)
end
# save the current message, as the syscall destroys all context
#
# This relies on linux to save and restore all registers
#
def save_message(function)
r8 = RegisterValue.new( :r8 , :Message)
function.source.add_code RegisterTransfer.new(function, Register.message_reg , r8 )
end
def restore_message(function)
r8 = RegisterValue.new( :r8 , :Message)
return_tmp = Register.tmp_reg :Integer
# get the sys return out of the way
function.source.add_code RegisterTransfer.new(function, Register.message_reg , return_tmp )
# load the stored message into the base RegisterMachine
function.source.add_code RegisterTransfer.new(function, r8 , Register.message_reg )
# save the return value into the message
function.source.add_code Register.set_slot( function, return_tmp , :message , :return_value )
# and "unroll" self and frame
end
end
extend ClassMethods
end
end
end