emu: factor out utils into own module

src/emu/dos.rs

@@ -1,5 +1,6 @@
 use emu::pc::Bus;
-use emu::i8088::{i8088, read_hi, read_lo, segoff_to_addr};
+use emu::i8088::i8088;
+use emu::util::{read_hi, read_lo, segoff_to_addr};
 
 pub fn interrupt(cpu: &mut i8088, bus: &mut Bus) {
   let svc = read_hi(&cpu.a);

src/emu/i8088.rs

@@ -3,9 +3,10 @@ use std::fmt::{Debug, Formatter};
 
 use super::byteorder::{ByteOrder, LittleEndian};
 
-use emu::operands::{Addr, Reg, RegHi};
+use emu::operands::{Addr, Reg, RegHi, RegLo};
 use emu::operations as ops;
 use emu::pc::Bus;
+use emu::util::segoff_to_addr;
 
 #[allow(non_camel_case_types)]
 #[derive(Clone, Debug, Default)]
@@ -302,37 +303,6 @@ impl i8088 {
   }
 }
 
-pub const fn segoff_to_addr(segment: u16, offset: u16) -> usize {
-  let segaddr = (segment as usize) << 4;
-  segaddr + offset as usize
-}
-
-pub fn read_hi(val: &Cell<u16>) -> u8 {
-  let mut buf = [0; 2];
-  LittleEndian::write_u16(&mut buf, val.get());
-  buf[1] as u8
-}
-
-pub fn read_lo(val: &Cell<u16>) -> u8 {
-  let mut buf = [0; 2];
-  LittleEndian::write_u16(&mut buf, val.get());
-  buf[0] as u8
-}
-
-pub fn write_hi(reg: &Cell<u16>, val: u8) {
-  let mut buf = [0; 2];
-  LittleEndian::write_u16(&mut buf, reg.get());
-  buf[1] = val;
-  reg.set(LittleEndian::read_u16(&buf))
-}
-
-pub fn write_lo(reg: &Cell<u16>, val: u8) {
-  let mut buf = [0; 2];
-  LittleEndian::write_u16(&mut buf, reg.get());
-  buf[1] = val;
-  reg.set(LittleEndian::read_u16(&buf));
-}
-
 impl From<u16> for Flags {
   fn from(flags: u16) -> Self {
     Self {

src/emu/mod.rs

@@ -5,3 +5,4 @@ pub mod i8088;
 mod operands;
 mod operations;
 pub mod pc;
+mod util;

src/emu/operands.rs

@@ -1,5 +1,6 @@
 use std::cell::Cell;
-use emu::i8088::{read_hi, read_lo, write_hi, write_lo};
+
+use emu::util::{read_hi, read_lo, write_hi, write_lo};
 use emu::pc::Bus;
 
 pub trait LValue<T> {

src/emu/operations.rs

@@ -1,8 +1,9 @@
 use emu::byteorder::{ByteOrder, LittleEndian};
 use emu::dos;
-use emu::i8088::{i8088, segoff_to_addr};
+use emu::i8088::i8088;
 use emu::operands::{Address, LValue, Reg, RValue};
 use emu::pc::Bus;
+use emu::util::segoff_to_addr;
 
 pub fn show(cpu: &mut i8088) {
   println!("{:#X?}", cpu);

src/emu/pc.rs

@@ -1,8 +1,9 @@
 use std::cell::Cell;
-use emu::i8088::{i8088, segoff_to_addr};
-
 use std::fmt::{Debug, Formatter};
 
+use emu::i8088::i8088;
+use emu::util::segoff_to_addr;
+
 const RAM_SIZE: usize = 128 * 1024;
 
 pub struct PC {

src/emu/util.rs

@@ -0,0 +1,33 @@
+use std::cell::Cell;
+use emu::byteorder::{ByteOrder, LittleEndian};
+
+pub const fn segoff_to_addr(segment: u16, offset: u16) -> usize {
+  let segaddr = (segment as usize) << 4;
+  segaddr + offset as usize
+}
+
+pub fn read_hi(val: &Cell<u16>) -> u8 {
+  let mut buf = [0; 2];
+  LittleEndian::write_u16(&mut buf, val.get());
+  buf[1] as u8
+}
+
+pub fn read_lo(val: &Cell<u16>) -> u8 {
+  let mut buf = [0; 2];
+  LittleEndian::write_u16(&mut buf, val.get());
+  buf[0] as u8
+}
+
+pub fn write_hi(reg: &Cell<u16>, val: u8) {
+  let mut buf = [0; 2];
+  LittleEndian::write_u16(&mut buf, reg.get());
+  buf[1] = val;
+  reg.set(LittleEndian::read_u16(&buf))
+}
+
+pub fn write_lo(reg: &Cell<u16>, val: u8) {
+  let mut buf = [0; 2];
+  LittleEndian::write_u16(&mut buf, reg.get());
+  buf[1] = val;
+  reg.set(LittleEndian::read_u16(&buf));
+}