snes.c 4.6 KB

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  1. /* sd2snes - SD card based universal cartridge for the SNES
  2. Copyright (C) 2009-2010 Maximilian Rehkopf <otakon@gmx.net>
  3. AVR firmware portion
  4. Inspired by and based on code from sd2iec, written by Ingo Korb et al.
  5. See sdcard.c|h, config.h.
  6. FAT file system access based on code by ChaN, Jim Brain, Ingo Korb,
  7. see ff.c|h.
  8. This program is free software; you can redistribute it and/or modify
  9. it under the terms of the GNU General Public License as published by
  10. the Free Software Foundation; version 2 of the License only.
  11. This program is distributed in the hope that it will be useful,
  12. but WITHOUT ANY WARRANTY; without even the implied warranty of
  13. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14. GNU General Public License for more details.
  15. You should have received a copy of the GNU General Public License
  16. along with this program; if not, write to the Free Software
  17. Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  18. snes.c: SNES hardware control and monitoring
  19. */
  20. #include <arm/NXP/LPC17xx/LPC17xx.h>
  21. #include "bits.h"
  22. #include "config.h"
  23. #include "uart.h"
  24. #include "snes.h"
  25. #include "memory.h"
  26. #include "fileops.h"
  27. #include "ff.h"
  28. #include "led.h"
  29. #include "smc.h"
  30. #include "timer.h"
  31. #include "cli.h"
  32. #include "fpga.h"
  33. #include "fpga_spi.h"
  34. uint8_t initloop=1;
  35. uint32_t saveram_crc, saveram_crc_old;
  36. extern snes_romprops_t romprops;
  37. volatile int reset_changed;
  38. volatile int reset_pressed;
  39. void prepare_reset() {
  40. snes_reset(1);
  41. delay_ms(SNES_RESET_PULSELEN_MS);
  42. if(romprops.ramsize_bytes && fpga_test() == FPGA_TEST_TOKEN) {
  43. writeled(1);
  44. save_sram(file_lfn, romprops.ramsize_bytes, SRAM_SAVE_ADDR);
  45. writeled(0);
  46. }
  47. rdyled(1);
  48. readled(1);
  49. writeled(1);
  50. snes_reset(0);
  51. while(get_snes_reset());
  52. snes_reset(1);
  53. fpga_dspx_reset(1);
  54. delay_ms(200);
  55. }
  56. void snes_init() {
  57. /* put reset level on reset pin */
  58. BITBAND(SNES_RESET_REG->FIOCLR, SNES_RESET_BIT) = 1;
  59. /* reset the SNES */
  60. snes_reset(1);
  61. }
  62. void snes_reset_pulse() {
  63. snes_reset(1);
  64. delay_ms(SNES_RESET_PULSELEN_MS);
  65. snes_reset(0);
  66. }
  67. /*
  68. * sets the SNES reset state.
  69. *
  70. * state: put SNES in reset state when 1, release when 0
  71. */
  72. void snes_reset(int state) {
  73. BITBAND(SNES_RESET_REG->FIODIR, SNES_RESET_BIT) = state;
  74. }
  75. /*
  76. * gets the SNES reset state.
  77. *
  78. * returns: 1 when reset, 0 when not reset
  79. */
  80. uint8_t get_snes_reset() {
  81. return !BITBAND(SNES_RESET_REG->FIOPIN, SNES_RESET_BIT);
  82. }
  83. /*
  84. * SD2SNES main loop.
  85. * monitors SRAM changes and other things
  86. */
  87. uint32_t diffcount = 0, samecount = 0, didnotsave = 0;
  88. uint8_t sram_valid = 0;
  89. void snes_main_loop() {
  90. if(!romprops.ramsize_bytes)return;
  91. if(initloop) {
  92. saveram_crc_old = calc_sram_crc(SRAM_SAVE_ADDR, romprops.ramsize_bytes);
  93. initloop=0;
  94. }
  95. saveram_crc = calc_sram_crc(SRAM_SAVE_ADDR, romprops.ramsize_bytes);
  96. sram_valid = sram_reliable();
  97. if(crc_valid && sram_valid) {
  98. if(saveram_crc != saveram_crc_old) {
  99. if(samecount) {
  100. diffcount=1;
  101. } else {
  102. diffcount++;
  103. didnotsave++;
  104. }
  105. samecount=0;
  106. }
  107. if(saveram_crc == saveram_crc_old) {
  108. samecount++;
  109. }
  110. if(diffcount>=1 && samecount==5) {
  111. printf("SaveRAM CRC: 0x%04lx; saving\n", saveram_crc);
  112. writeled(1);
  113. save_sram(file_lfn, romprops.ramsize_bytes, SRAM_SAVE_ADDR);
  114. writeled(0);
  115. didnotsave=0;
  116. }
  117. if(didnotsave>50) {
  118. printf("periodic save (sram contents keep changing...)\n");
  119. diffcount=0;
  120. writeled(1);
  121. save_sram(file_lfn, romprops.ramsize_bytes, SRAM_SAVE_ADDR);
  122. didnotsave=0;
  123. writeled(1);
  124. }
  125. saveram_crc_old = saveram_crc;
  126. }
  127. printf("crc=%lx crc_valid=%d sram_valid=%d diffcount=%ld samecount=%ld, didnotsave=%ld\n", saveram_crc, crc_valid, sram_valid, diffcount, samecount, didnotsave);
  128. }
  129. /*
  130. * SD2SNES menu loop.
  131. * monitors menu selection. return when selection was made.
  132. */
  133. uint8_t menu_main_loop() {
  134. uint8_t cmd = 0;
  135. sram_writebyte(0, SRAM_CMD_ADDR);
  136. while(!cmd) {
  137. if(!get_snes_reset()) {
  138. while(!sram_reliable())printf("hurr\n");
  139. cmd = sram_readbyte(SRAM_CMD_ADDR);
  140. }
  141. if(get_snes_reset()) {
  142. cmd = 0;
  143. }
  144. sleep_ms(20);
  145. cli_entrycheck();
  146. }
  147. return cmd;
  148. }
  149. void get_selected_name(uint8_t* fn) {
  150. uint32_t addr;
  151. addr = sram_readlong(SRAM_PARAM_ADDR);
  152. printf("fd addr=%lx\n", addr);
  153. sram_readblock(fn, addr + 7 + SRAM_MENU_ADDR, 256);
  154. }
  155. void snes_bootprint(void* msg) {
  156. sram_writeblock(msg, SRAM_CMD_ADDR, 33);
  157. }
  158. void snes_menu_errmsg(int err, void* msg) {
  159. sram_writeblock(msg, SRAM_CMD_ADDR+1, 64);
  160. sram_writebyte(err, SRAM_CMD_ADDR);
  161. }