ref: 2c5055f6104f5e7c5b9aabff1c9df26afa4e7021
parent: dd369f3199f6790bfff142754a8f0507a17e3276
author: Rangi <remy.oukaour+rangi42@gmail.com>
date: Thu Jul 23 18:00:59 EDT 2020
Generate the Stadium 2 checksum data with pfero's tool instead of raw INCBINs
--- a/Makefile
+++ b/Makefile
@@ -116,9 +116,16 @@
pokecrystal_debug_opt = -Cjv -t PM_CRYSTAL -i BYTE -n 0 -k 01 -l 0x33 -m 0x10 -r 3 -p 0
pokecrystal11_debug_opt = -Cjv -t PM_CRYSTAL -i BYTE -n 1 -k 01 -l 0x33 -m 0x10 -r 3 -p 0
+pokecrystal_base = us
+pokecrystal11_base = us
+pokecrystal_au_base = us
+pokecrystal_debug_base = dbg
+pokecrystal11_debug_base = dbg
+
%.gbc: $$(%_obj) layout.link
$(RGBLINK) -n $*.sym -m $*.map -l layout.link -o $@ $(filter %.o,$^)
$(RGBFIX) $($*_opt) $@
+ tools/stadium --base $($*_base) $@
### LZ compression rules
--- a/layout.link
+++ b/layout.link
@@ -306,7 +306,7 @@
"Crystal Events"
ROMX $7f
org $7de0
- "Mobile Stadium 2"
+ "Stadium 2 Checksums"
WRAM0
"Stack"
"Audio RAM"
--- a/main.asm
+++ b/main.asm
@@ -724,20 +724,12 @@
INCLUDE "engine/events/odd_egg.asm"
-SECTION "Mobile Stadium 2", ROMX
+SECTION "Stadium 2 Checksums", ROMX[$7DE0], BANK[$7F]
-if DEF(_CRYSTAL_AU)
-INCBIN "mobile/stadium/stadium2_au.bin"
-elif DEF(_CRYSTAL11)
-if DEF(_DEBUG)
-INCBIN "mobile/stadium/stadium2_11_debug.bin"
-else
-INCBIN "mobile/stadium/stadium2_11.bin"
-endc
-else
-if DEF(_DEBUG)
-INCBIN "mobile/stadium/stadium2_debug.bin"
-else
-INCBIN "mobile/stadium/stadium2.bin"
-endc
-endc
+; The end of the ROM is taken up by checksums of the content, apparently used
+; by Pokémon Stadium 2 due to the checksums' "N64PS3" header. (In Japan,
+; Pokémon Stadium Gold and Silver was the third Stadium release for N64.)
+; This SECTION reserves space for those checksums.
+; If it is removed, also remove the "tools/stadium" command in the Makefile.
+
+ ds $220
binary files a/mobile/stadium/stadium2.bin /dev/null differ
binary files a/mobile/stadium/stadium2_11.bin /dev/null differ
binary files a/mobile/stadium/stadium2_11_debug.bin /dev/null differ
binary files a/mobile/stadium/stadium2_au.bin /dev/null differ
binary files a/mobile/stadium/stadium2_debug.bin /dev/null differ
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -10,7 +10,8 @@
palette \
pokemon_animation \
pokemon_animation_graphics \
- gfx
+ gfx \
+ stadium
all: $(tools)
@:
--- /dev/null
+++ b/tools/stadium.c
@@ -1,0 +1,155 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <getopt.h>
+#include <string.h>
+#include <stdint.h>
+
+#include "common.h"
+
+// The Game Boy cartridge header stores a global checksum at 0x014E-0x014F
+#define GLOBALOFF 0x014E
+// "base" data; Crystal-only
+#define BASESIZE 24
+// ASCII "N64PS3" header
+#define N64PS3SIZE 6
+// N64PS3 + CRC
+#define HEADERSIZE (N64PS3SIZE + 2)
+// Checksum every half-bank
+#define CHECKSIZE 0x2000
+// The CRC initial value (also used for checksums)
+#define CRC_INIT 0xFEFE
+// The CRC polynomial value
+#define CRC_POLY 0xC387
+
+typedef enum Base { BASE_NONE, BASE_US, BASE_EU, BASE_DEBUG } Base;+
+uint8_t us_base[BASESIZE] = {'b', 'a', 's', 'e',+ 0x01, 0x00, 0xBF, 0x6B, 0x40, 0x11, 0x00, 0x22, 0x00, 0x3A,
+ 0xF3, 0x38, 0x18, 0xFF, 0xFF, 0x0F, 0x07, 0x10, 0x68, 0x07};
+
+uint8_t eu_base[BASESIZE] = {'b', 'a', 's', 'e',+ 0x01, 0x01, 0x1E, 0xCF, 0x00, 0x10, 0x00, 0x00, 0x00, 0x0C,
+ 0xA3, 0x38, 0x00, 0xFF, 0xFF, 0x07, 0x00, 0x00, 0x00, 0x14};
+
+uint8_t dbg_base[BASESIZE] = {'b', 'a', 's', 'e',+ 0x01, 0x00, 0x07, 0x82, 0x40, 0x10, 0x00, 0x22, 0x00, 0x3A,
+ 0xE3, 0x38, 0x00, 0xFF, 0xFF, 0x07, 0x07, 0x10, 0x68, 0x06};
+
+uint8_t n64ps3[N64PS3SIZE] = {'N', '6', '4', 'P', 'S', '3'};+
+static void usage(void) {+ fprintf(stderr, "Usage: stadium [-h|--help] [-b|--base us|eu|dbg] romfile\n");
+}
+
+void parse_args(int argc, char *argv[], Base *b) {+ struct option long_options[] = {+ {"base", required_argument, 0, 'b'},+ {"help", no_argument, 0, 'h'},+ {0}+ };
+ for (int opt = 0; opt != -1;) {+ switch (opt = getopt_long(argc, argv, "hb:", long_options)) {+ case 'h':
+ usage();
+ exit(0);
+ break;
+ case 'b':
+ *b = !strcmp(optarg, "us") ? BASE_US :
+ !strcmp(optarg, "eu") ? BASE_EU :
+ !strcmp(optarg, "dbg") ? BASE_DEBUG :
+ BASE_NONE;
+ break;
+ case 0:
+ case -1:
+ break;
+ default:
+ usage();
+ exit(1);
+ break;
+ }
+ }
+}
+
+#define SET_U16BE(file, off, v) do { \+ file[(off) + 0] = (uint8_t)(((v) & 0xFF00) >> 8); \
+ file[(off) + 1] = (uint8_t)(((v) & 0x00FF) >> 0); \
+} while (0)
+
+void calculate_checksums(uint8_t *file, int filesize, Base base) {+ int NUMCHECKS = filesize / CHECKSIZE;
+ int DATASIZE = HEADERSIZE + NUMCHECKS * 2; // 2 bytes per checksum
+ int ORIGIN = filesize - DATASIZE; // Stadium data goes at the end of the file
+
+ // Clear the global checksum
+ SET_U16BE(file, GLOBALOFF, 0);
+
+ // Write the appropriate base data, or none
+ int BASEOFF = ORIGIN - BASESIZE;
+ if (base == BASE_US) {+ memcpy(file + BASEOFF, us_base, BASESIZE);
+ } else if (base == BASE_EU) {+ memcpy(file + BASEOFF, eu_base, BASESIZE);
+ } else if (base == BASE_DEBUG) {+ memcpy(file + BASEOFF, dbg_base, BASESIZE);
+ }
+
+ // Initialize the Stadium data (this should be free space anyway)
+ memset(file + ORIGIN, 0, DATASIZE);
+ memcpy(file + ORIGIN, n64ps3, N64PS3SIZE);
+
+ // Calculate the half-bank checksums
+ for (int i = 0; i < NUMCHECKS; i++) {+ uint16_t checksum = CRC_INIT;
+ for (int j = 0; j < CHECKSIZE; j++) {+ checksum += file[i * CHECKSIZE + j];
+ }
+ SET_U16BE(file, ORIGIN + HEADERSIZE + i * 2, checksum);
+ }
+
+ // Initialize the CRC table
+ uint16_t crc_table[256];
+ for (int i = 0; i < 256; i++) {+ uint16_t c = i;
+ uint16_t rem = 0;
+ for (int y = 0; y < 8; y++) {+ rem = (rem >> 1) ^ ((rem ^ c) & 1 ? CRC_POLY : 0);
+ c >>= 1;
+ }
+ crc_table[i] = rem;
+ }
+
+ // Calculate the CRC of the half-bank checksums
+ uint16_t crc = CRC_INIT;
+ for (int i = ORIGIN + HEADERSIZE; i < ORIGIN + DATASIZE; i++) {+ crc = (crc >> 8) ^ crc_table[(crc & 0xFF) ^ file[i]];
+ }
+ SET_U16BE(file, ORIGIN + HEADERSIZE - 2, crc);
+
+ // Calculate the global checksum
+ uint16_t globalsum = 0;
+ for (int i = 0; i < filesize; i++) {+ globalsum += file[i];
+ }
+ SET_U16BE(file, GLOBALOFF, globalsum);
+}
+
+int main(int argc, char *argv[]) {+ Base base = BASE_NONE;
+ parse_args(argc, argv, &base);
+
+ argc -= optind;
+ argv += optind;
+ if (argc < 1) {+ usage();
+ exit(1);
+ }
+
+ char *filename = argv[0];
+ int filesize;
+ uint8_t *file = read_u8(filename, &filesize);
+ calculate_checksums(file, filesize, base);
+ write_u8(filename, file, filesize);
+
+ return 0;
+}