Updated the parser to better handle parameters, sort of and including a string length assembly program to use as a test for the whole assembler.

misc/test.asm

@@ -1,27 +1,27 @@
-;.org 0x100
+.db video_start 0xF37F
 .db msg "Hello, world!", 0
-.db more_stuff "AA", 0
-copy r7, msg ; //
-;cmp r8, msg ;1000 1111
-;add r4, 0x42
-;sub r1, r8
-int 20
-jz 45
-jmp msg
-in 10
-call more_stuff
-ret
-yld
 
-;copy r1, 45 ;//B0 = 10110000
-;copy 2, 45
-;loop:
-;    cmp r1, 0
-;    jz loop
-;    add r1, 1
-;mov r1, 5   ; move the immediate value 5 into r1
-;add r1,5   ; add 5 into r1
-;int 21      ; maybe that will call some string drawing BIOS-like routine
-;ret
-; 4 byte header
-; | Address of First Opcode (2 bytes) | End of Binary (2 bytes) |
+load r1, [msg] ; Because the lod* instructions can't load an address
+               ; from anything but a register, this becomes laa r1, [msg]
+
+;Routine: string_length
+;In: String address in r1
+;Out: Length in R2
+
+string_length:
+loadb r3, [r1] ; Load the byte from the address in R1, into R3
+load r2, 0 ; String length
+cmp r3, 0 ; Is R3 a null byte?
+je end
+inc r2
+
+start:
+    inc r1 ; next char
+    loadb r3, [r1] ; Load the next character byte into R3
+    cmpi r3, 0 ; Null byte?
+    je end
+    inc r2 ; Nope, increment the length counter
+    jmp start
+
+end:
+ret