decoder8086.odin

@@ -15,13 +15,6 @@ Register :: struct {
     code: u8,
 }
 
-RegMemMode :: enum {
-    Memory00 = 0b00,
-    Memory08 = 0b01,
-    Memory16 = 0b10,
-    Register = 0b11,
-};
-
 registers := [8]Register {
     {fullname = "ax", bytename = "al", code = 0b000},
     {fullname = "cx", bytename = "cl", code = 0b001},
@@ -33,70 +26,30 @@ registers := [8]Register {
     {fullname = "di", bytename = "bh", code = 0b111},
 }
 
-Instruction :: struct {
-    mask: u8,
-    encoding: u8,
-    name: string,
-    desc: string,
-}
-
-instructions := [?]Instruction {
-    { mask = 0b11111100, encoding = 0b10001000, name = "mov", desc = "Register/memory to/from register" },
-    { mask = 0b11111110, encoding = 0b11000110, name = "mov", desc = "Immediate to register/memory" },
-    { mask = 0b11110000, encoding = 0b10110000, name = "mov", desc = "Immediate to register" },
-    { mask = 0b11111110, encoding = 0b10100000, name = "mov", desc = "Memory to accumulator" },
-    { mask = 0b11111110, encoding = 0b10100010, name = "mov", desc = "Accumulator to memory" },
-    { mask = 0b11111111, encoding = 0b10001110, name = "mov", desc = "Register/memory to segment register" },
-    { mask = 0b11111111, encoding = 0b10001100, name = "mov", desc = "Segment register to register/memory" },
-}
-
-inst_map := make(map[u8]Instruction)
-
 main :: proc() {
     ax := registers[0]
     ax.value.full = 52428
-    f,err := os.open(len(os.args) > 1 ? os.args[1] : "./asm_files/01-02-39.bin")
+    f,err := os.open(len(os.args) > 1 ? os.args[1] : "./asm_files/01-01-38.bin")
     if err != os.ERROR_NONE {
         os.exit(1)
     }
     defer os.close(f)
 
-    data := make([]u8, 512)
+    data := make([]u8, 256)
     bytes_read, err2 := os.read(f, data)
     if err2 != nil {
         // ...
         os.exit(1)
     }
-
-    for inst in instructions {
-        inst_map[inst.encoding] = inst
-    }
-
-    if true {
-        for i in 0..<bytes_read {
-            fmt.printfln("%b", data[i])
-            mask: u8 = 0b11111111
-            for i in 0..=4 {
-                encoding := data[i] & mask
-                if inst, ok := inst_map[encoding]; ok {
-                    fmt.printfln("%b, %v", encoding, inst.desc)
-                    // fmt.println(inst.desc)
-                    break
-                }
-                mask <<= 1
-            }
-            // fmt.println("=============")
-        }
-        os.exit(0)
-    }
+    // mov cx, bx                      ; mov 001, 011
+    // mov dx, bx
 
     read_next := false
     src_dst := true
     is_word := false
     prev :u8 = 0
     fmt.println("bits 16\n")
-    for i in 0..<bytes_read {
-        b := data[i]
+    for b in data {
         if read_next {
             mod := (b & 0b11000000) >> 6
             reg := (b & 0b00111000) >> 3