improve readme a bit

twasm/README.md

@@ -526,3 +526,70 @@ hlt
 
 0xF4 ; HLT
 ```
+
+#### program output with the function `print`, each comma-seperated `db` value put onto its own line
+
+editted output of `x/512xb 0x00070000` in [gdb](https://www.sourceware.org/gdb/)
+
+the following is somewhat correct! I just need to a) null-terminate 8-byte chars and b) define all the addresses currently represented as `0xff 0xff 0xff 0xff`
+
+```
+0x48 0xff 0xf2
+0x48 0xff 0xf0
+0x48 0xff 0xf6
+0xc7 0xc2 0xf8 0x03 0x00 0x00
+0x8a 0x06
+0x80 0xf8 0x00
+0x0f 0x84 0xff 0xff 0xff 0xff
+0x66 0xee
+0x48 0xff 0xc6
+0xe9 0xff 0xff 0xff 0xff
+0x48 0x8f 0xc6
+0x48 0x8f 0xc0
+0x48 0x8f 0xc2
+0xc3
+0x48 0xff 0xf6
+0xc7 0xc6 0xff 0xff 0xff 0xff
+0xe8 0xff 0xff 0xff 0xff
+0x48 0x8f 0xc6
+0xe9 0xff 0xff 0xff 0xff
+0x48 0xff 0xf6
+0xc7 0xc6 0xff 0xff 0xff 0xff
+0xe8 0xff 0xff 0xff 0xff
+0x48 0x8f 0xc6
+0xe9 0xff 0xff 0xff 0xff
+0x48 0xff 0xf6
+0xc7 0xc6 0xff 0xff 0xff 0xff
+0xe8 0xff 0xff 0xff 0xff
+0x48 0x8f 0xc6
+0xe9 0xff 0xff 0xff 0xff
+0x48 0xff 0xf6
+0xc7 0xc6 0xff 0xff 0xff 0xff
+0xe8 0xff 0xff 0xff 0xff
+0x48 0x8f 0xc6
+0xe9 0xff 0xff 0xff 0xff
+0x1b 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x5b 0x33 0x36 0x6d 0x00 0x00 0x00 0x00
+0x7b 0x44 0x45 0x42 0x55 0x47 0x5d 0x3a
+0x1b 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x5b 0x30 0x6d 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x1b 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x5b 0x31 0x3b 0x33 0x31 0x6d 0x00 0x00
+0x7b 0x45 0x52 0x52 0x4f 0x52 0x5d 0x3a
+0x1b 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x5b 0x30 0x6d 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x1b 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x5b 0x31 0x3b 0x33 0x33 0x6d 0x00 0x00
+0x5b 0x54 0x45 0x53 0x54 0x5d 0x3a 0x20
+0x1b 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x5b 0x30 0x6d 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x1b 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x5b 0x31 0x3b 0x33 0x35 0x6d 0x00 0x00
+0x5b 0x57 0x41 0x52 0x4e 0x5d 0x3a 0x20
+0x1b 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x5b 0x30 0x6d 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+```

twasm/asm/main.asm

@@ -1302,6 +1302,7 @@ get_opcode:
   .found:
     shl eax, 4
     mov dl, [esi + 8 + opcodes.by_id + eax]
+    and edx, 0xFF
     mov al, [esi + 2 + opcodes.by_id + eax]
     and eax, 0xFF
     ret
@@ -1347,6 +1348,7 @@ get_reg_bits:
 ; ------------------------------------------------------------------------------
 
 tokenise:
+  mov rbp, rsp
                ; rdi -> current byte of program
   xor eax, eax ; rax = number of tokens processed
   xor edx, edx ; dl = current byte of program
@@ -1653,6 +1655,7 @@ tokenise:
     jmp .loop
 
   .break:
+    mov rsp, rbp
     ret
 
   ; state