ft: partially implement Group 5 instructions

src/disasm.rs

@@ -613,7 +613,20 @@ impl Disassembler {
                         _ => panic!("Illegal Group 4 mnemonic"),
                     }
                 }
-                0xFF => todo!("Group 5"),
+                0xFF => {
+                    let (target, reg) = self.parse_modrm_byte(Operand::Word(0));
+                    match reg {
+                        0b000 => Mnemonic::INC_Mod(target),
+                        0b001 => Mnemonic::DEC_Mod(target),
+                        0b010 => Mnemonic::CALL_Mod(target),
+                        0b011 => todo!("Implement CALL Mp"),
+                        0b100 => Mnemonic::JMP_Mod(target),
+                        0b101 => todo!("Implement JMP Mp"),
+                        0b110 => Mnemonic::PUSH_Mod(target),
+                        // 0b111 => unused
+                        _ => panic!("Illegal Group 5 mnemonic"),
+                    }
+                }
 
                 _ => {
                     eprintln!("Encountered unknown instruction '0x{:x}'", opcode);

src/instructions.rs

@@ -77,6 +77,7 @@ pub enum Mnemonic {
     // PUSH
     PUSH_R(Register),
     PUSH_S(SegmentRegister),
+    PUSH_Mod(ModRmTarget),
     // POP
     POP_S(SegmentRegister), // POP to Segment Register
     POP_R(Register),        // POP to Register
@@ -203,10 +204,12 @@ pub enum Mnemonic {
     // CALL
     CALL_p(Pointer),
     CALL_v(Word),
+    CALL_Mod(ModRmTarget),
     // JUMP
     JMP_p(Pointer),
     JMP_b(Byte),
     JMP_v(Word),
+    JMP_Mod(ModRmTarget),
     // WAIT
     WAIT,
     // Push/Pop Flags