Add support for multiple charmaps

This adds two new directives: newcharmap and setcharmap.
newcharmap creates a new charmap and switches to it.
setcharmap switches to an existing charmap.

include/asm/charmap.h

@@ -25,13 +25,16 @@ struct Charnode {
 };
 
 struct Charmap {
+	char name[MAXSYMLEN + 1];
 	int32_t charCount; /* user-side count. */
 	int32_t nodeCount; /* node-side count. */
 	struct Charnode nodes[MAXCHARNODES]; /* first node is reserved for the root node in charmap. */
+	struct Charmap *next; /* next charmap in hash table bucket */
 };
 
-int32_t readUTF8Char(char *destination, char *source);
-
+void charmap_InitMain(void);
+struct Charmap *charmap_New(const char *name, const char *baseName);
+void charmap_Set(const char *name);
 int32_t charmap_Add(char *input, uint8_t output);
 int32_t charmap_Convert(char **input);
 

include/asm/main.h

@@ -11,6 +11,7 @@
 
 #include <stdbool.h>
 #include <stdint.h>
+#include <stdio.h>
 
 #include "helpers.h"
 

include/asm/symbol.h

@@ -51,7 +51,7 @@ struct sSymbol {
 /* Symbol has a constant value, will not be changed during linking */
 #define SYMF_CONST	0x200
 
-uint32_t calchash(char *s);
+uint32_t sym_CalcHash(const char *s);
 void sym_SetExportAll(uint8_t set);
 void sym_AddLocalReloc(char *tzSym);
 void sym_AddReloc(char *tzSym);

include/asm/util.h

@@ -0,0 +1,17 @@
+/*
+ * This file is part of RGBDS.
+ *
+ * Copyright (c) 1997-2019, Carsten Sorensen and RGBDS contributors.
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#ifndef RGBDS_UTIL_H
+#define RGBDS_UTIL_H
+
+#include <stdint.h>
+
+uint32_t calchash(const char *s);
+int32_t readUTF8Char(char *dest, char *src);
+
+#endif /* RGBDS_UTIL_H */