Disallow SMS ROMs for now.

src/assembler/tokenizer.c

@@ -154,8 +154,9 @@ static ErrorInfo* handle_block_directive(
 static ErrorInfo* parse_data(
     const ASMLine *line, ASMData **data_ptr, size_t offset)
 {
-    parser_func parser = (parser_func) parse_string;
     const char *directive;
+    parser_func parser = (parser_func) parse_string;
+
     if (IS_DIRECTIVE(line, DIR_BYTE)) {
         directive = DIR_BYTE;
         parser = parse_bytes;

src/rom.c

@@ -213,6 +213,12 @@ const char* rom_open(ROM **rom_ptr, const char *path)
         return rom_err_badheader;
     }
 
+    if (rom->region_code == 3 || rom->region_code == 4) {
+        // TODO: support SMS ROMs eventually?
+        rom_close(rom);
+        return rom_err_sms;
+    }
+
     *rom_ptr = rom;
     return NULL;
 }

src/rom.h

@@ -23,6 +23,7 @@ static const char* rom_err_notfile   = "Is not a regular file";
 static const char* rom_err_badsize   = "Invalid size";
 static const char* rom_err_badread   = "Couldn't read the entire file";
 static const char* rom_err_badheader = "Invalid header";
+static const char* rom_err_sms       = "Master System ROMs are not supported";
 
 /* Structs */