fox32rom: Add a small debug routine for printing to the terminal

debug.asm

@@ -0,0 +1,17 @@
+; debug routines
+
+; print a string to the terminal
+; inputs:
+; r0: pointer to null-terminated string
+; outputs:
+; none
+debug_print:
+    push r1
+debug_print_loop:
+    mov r1, 0x00000000
+    out r1, [r0]
+    inc r0
+    cmp.8 [r0], 0x00
+    ifnz jmp debug_print_loop
+    pop r1
+    ret

main.asm

@@ -164,6 +164,7 @@ mount_boot_disk:
     ; code
     #include "boot.asm"
     #include "background.asm"
+    #include "debug.asm"
     #include "overlay.asm"
     #include "memory.asm"
     #include "menu.asm"