From c372a96b7c8483fe8d0d3a781d4d09282d9389af Mon Sep 17 00:00:00 2001
From: Jared Burce <jaredr@gmail.com>
Date: Fri, 12 Mar 2021 04:02:27 -0800
Subject: [PATCH] emu: all MOV opcodes (no modrm base/index/displacement modes
 yet)

---
 src/emu/i8088.rs    | 42 +++++++++++++++++++++++++++++++++++++++---
 src/emu/operands.rs | 17 +++++++++++++++++
 2 files changed, 56 insertions(+), 3 deletions(-)

diff --git a/src/emu/i8088.rs b/src/emu/i8088.rs
index e0c506a..d533972 100644
--- a/src/emu/i8088.rs
+++ b/src/emu/i8088.rs
@@ -122,6 +122,15 @@ macro_rules! step {
      }
    } };
 
+  (@modrm8 $cookie:tt, $cpu:expr, $bus:expr, $prefix:tt,
+   ($modrm_val:ident, $modrm16:tt, { $($val:literal => $($args:ident = $argrhs:tt),*),*$(,)? } )) => { {
+     let modrm_val = $modrm_val & !0x38;
+     match modrm_val {
+       $( $val => step!(@push $cookie, ($($args = $argrhs)* ) ) ),*,
+       _ => unimplemented!("modrm: {:02X}({:02X})\ncpu: {:#X?}", $modrm_val, modrm_val, $cpu)
+     }
+   } };
+
   (@prefix $cookie:tt, $cpu:expr, $bus:expr, ($segment:ident, $prefix_loop:lifetime), $modrm:tt) => { continue $prefix_loop; };
 
   (@r16 $cookie:tt, $cpu:expr, $bus:expr, $prefix:tt, ($modrm:ident, $modrm16:tt, $modrm8:tt)) => {
@@ -246,14 +255,41 @@ impl i8088 {
           0x2e => nop[seg=cs, prefix] / 2,
           0x36 => nop[seg=ss, prefix] / 2,
           0x3e => nop[seg=ds, prefix] / 2,
-          0x60 => show[cpu] / 0,  // Fake opcode for debugging
+          0x60 => show[cpu] / 0,           // Fake opcode for debugging
           0x61 => peek[seg=ds, addr] / 0,  // Fake opcode for debugging
+          0x88 _ => mov[modrm8, r8] / "2/13+",
+          0x89 _ => mov[modrm16, r16] / "2/13+",
+          0x8A _ => mov[r8, modrm8] / "2/12+",
           0x8B _ => mov[r16, modrm16] / "2/12+",
-          0x8C: { 0x08 => mov[modrm16, reg=cs] / "2/13+", },
-          0x8E: { 0x18 => mov[reg=ds, modrm16] / "2/12+", },
+          0x8C: { 0x00 => mov[modrm16, reg=es] / "2/13+",
+                  0x08 => mov[modrm16, reg=cs] / "2/13+",
+                  0x10 => mov[modrm16, reg=ss] / "2/13+",
+                  0x18 => mov[modrm16, reg=ds] / "2/13+", },
+          0x8E: { 0x00 => mov[reg=es, modrm16] / "2/12+",
+                  0x08 => mov[reg=cs, modrm16] / "2/12+",
+                  0x10 => mov[reg=ss, modrm16] / "2/12+",
+                  0x18 => mov[reg=ds, modrm16] / "2/12+", },
           0x90 => nop[] / 3,
+          0xA0 => mov[reglo=a, addr] / 14,
+          0xA1 => mov[reg=a, addr] / 14,
+          0xA2 => mov[addr, reglo=a] / 14,
+          0xA3 => mov[addr, reg=a] / 14,
+          0xB0 => mov[reglo=a, d8] / 4,
+          0xB1 => mov[reglo=c, d8] / 4,
+          0xB2 => mov[reglo=d, d8] / 4,
+          0xB3 => mov[reglo=b, d8] / 4,
           0xB4 => mov[reghi=a, d8] / 4,
+          0xB5 => mov[reghi=c, d8] / 4,
+          0xB6 => mov[reghi=d, d8] / 4,
+          0xB7 => mov[reghi=b, d8] / 4,
+          0xB8 => mov[reg=a, d16] / 4,
+          0xB9 => mov[reg=c, d16] / 4,
           0xBA => mov[reg=d, d16] / 4,
+          0xBB => mov[reg=b, d16] / 4,
+          0xBC => mov[reg=sp, d16] / 4,
+          0xBD => mov[reg=bp, d16] / 4,
+          0xBE => mov[reg=si, d16] / 4,
+          0xBF => mov[reg=di, d16] / 4,
           0xC3 => ret[reg=ip, regval=ss, reg=sp, mem] / 20,
           0xCD => int[cpu, bus, d8] / 71,
           0xE8 => call[reg=ip, regval=ss, reg=sp, mem, rel16] / 23,
diff --git a/src/emu/operands.rs b/src/emu/operands.rs
index 0f7bfb4..85fe90d 100644
--- a/src/emu/operands.rs
+++ b/src/emu/operands.rs
@@ -56,6 +56,23 @@ impl RValue<u8> for Addr<'_> {
   }
 }
 
+impl LValue<u16> for Addr<'_> {
+  fn write(&mut self, val: u16) {
+    let buf = val.to_le_bytes();
+    self.bus.write(self.addr,     buf[0]);
+    self.bus.write(self.addr + 1, buf[1]);
+  }
+}
+
+impl RValue<u16> for Addr<'_> {
+  fn read(&self) -> u16 {
+    let mut buf = [0u8; 2];
+    buf[0] = self.bus.read(self.addr);
+    buf[1] = self.bus.read(self.addr + 1);
+    u16::from_le_bytes(buf)
+  }
+}
+
 pub struct Reg<'a> {
   pub reg: &'a Cell<u16>
 }