Add .LOOP instruction, dump memory to disk with cli arg

.gitignore

@@ -5,3 +5,4 @@
 /decoder8086
 /performance-aware
 /sim8086
+/listing-*.data

asm_files/list-0054.asm

@@ -0,0 +1,43 @@
+; ========================================================================
+;
+; (C) Copyright 2023 by Molly Rocket, Inc., All Rights Reserved.
+;
+; This software is provided 'as-is', without any express or implied
+; warranty. In no event will the authors be held liable for any damages
+; arising from the use of this software.
+;
+; Please see https://computerenhance.com for further information
+;
+; ========================================================================
+
+; ========================================================================
+; LISTING 54
+; ========================================================================
+
+bits 16
+
+; Start image after one row, to avoid overwriting our code!
+mov bp, 64*4
+
+mov dx, 0
+y_loop_start:
+	
+	mov cx, 0
+	x_loop_start:
+		; Fill pixel
+		mov word [bp + 0], cx ; Red
+		mov word [bp + 2], dx ; Blue
+		mov byte [bp + 3], 255 ; Alpha
+			
+		; Advance pixel location
+		add bp, 4
+			
+		; Advance X coordinate and loop
+		add cx, 1
+		cmp cx, 64
+		jnz x_loop_start
+	
+	; Advance Y coordinate and loop
+	add dx, 1
+	cmp dx, 64
+	jnz y_loop_start

asm_files/list-0055.asm

@@ -0,0 +1,53 @@
+; ========================================================================
+;
+; (C) Copyright 2023 by Molly Rocket, Inc., All Rights Reserved.
+;
+; This software is provided 'as-is', without any express or implied
+; warranty. In no event will the authors be held liable for any damages
+; arising from the use of this software.
+;
+; Please see https://computerenhance.com for further information
+;
+; ========================================================================
+
+; ========================================================================
+; LISTING 55
+; ========================================================================
+
+bits 16
+
+; Start image after one row, to avoid overwriting our code!
+mov bp, 64*4
+
+; Draw the solid rectangle red/blue/alpha
+mov dx, 64
+y_loop_start:
+	
+	mov cx, 64
+	x_loop_start:
+		mov byte [bp + 0], cl  ; Red
+		mov byte [bp + 1], 0   ; Green
+		mov byte [bp + 2], dl  ; Blue
+		mov byte [bp + 3], 255 ; Alpha
+		add bp, 4
+			
+		loop x_loop_start
+	
+	sub dx, 1
+	jnz y_loop_start
+
+; Add the line rectangle green
+mov bp, 64*4 + 4*64 + 4
+mov bx, bp
+mov cx, 62
+outline_loop_start:
+	
+	mov byte [bp + 1], 255 ; Top line
+	mov byte [bp + 61*64*4 + 1], 255 ; Bottom line
+	mov byte [bx + 1], 255 ; Left line
+	mov byte [bx + 61*4 + 1], 255 ; Right  line
+	
+	add bp, 4
+	add bx, 4*64
+			
+	loop outline_loop_start

execution.odin

@@ -111,6 +111,9 @@ execute_instruction :: proc(cpu: ^Cpu, inst: Instruction) {
         case .JP, .JPE:  jump =  cpu.flags[.PF]
         case .JB, .JNAE: jump =  cpu.flags[.CF]
 
+        case .LOOP:
+            cpu.registers[.cx].full -= 1
+            jump = cpu.registers[.cx].full != 0
         case .LOOPNZ, .LOOPNE:
             cpu.registers[.cx].full -= 1
             // According to this resource, the loopnz inst does not change any flags

sim8086.odin

@@ -95,4 +95,18 @@ main :: proc() {
     if what_to_print == "instructions" || what_to_print == "all" {
         print_instructions_stdout(instructions_list[:])
     }
+    if len(os.args) > 3 && os.args[3] == "dump" {
+        f2,open_err := os.open("./listing-54.data", os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0o644)
+        if open_err == nil {
+            bytes_written,write_err := os.write(f2, cpu.memory[:])
+            if write_err == nil {
+                fmt.println("Dumpped", bytes_written, "to disk: listing-54.data")
+            } else {
+                fmt.println("Error2:", write_err)
+            }
+        } else {
+            fmt.println("Error1:", open_err)
+        }
+        defer os.close(f)
+    }
 }