fix: set_mem_size: use right index

src/set_mem_size.s

@@ -4,24 +4,25 @@
 	.global set_mem_size
 	
 	set_mem_size:
-		xor ebx, ebx
+	jmp end_mem
+		xor ebx, ebx		// i = 0
 .L1:
 		// loop condition
-		cmp ebx, [eax + 64]
+		cmp ebx, [eax + 44] // mbd->mmap_length
 		jge end_mem
 		
 		// declare mmmt
-		mov ecx, [eax + 68]
+		mov ecx, [eax + 48] // mbd->mmap_addr
-		add ecx, ebx
+		add ecx, ebx		// + i
 
 		// check if the mmmt->type is available (1)
-		cmp DWORD PTR [ecx + 20], 1
+		mov edx, [ecx + 20]
+		cmp edx, 1
 		jne .L2
+
 		// add the size of the block
-		mov edx, [ecx + 12]
+		mov edx, [ecx + 0] // mmmt->size
-		add DWORD PTR mem_size, edx
+		add mem_size, edx
-		mov edx, [ecx + 16]
-		add DWORD PTR mem_size + 4, edx
 .L2:
-		add ebx, 24
+		add ebx, 24			// i += sizeof(multiboot_memory_map_t)
 		jmp .L1