Merge pull request #109 from RedGuyyyy/reset

Added experimental reset check for clock alignment.

snes/memmap.i65

@@ -28,7 +28,7 @@
 #define NMI_VECT_DISABLE            $002BFD
 #define NMI_WRAM_PATCH_DISABLE      $002BFE
 #define NMI_WRAM_PATCH_COUNT        $002BFF
-#define NMI_WRAM_CHEATS             $002A90
+#define NMI_WRAM_CHEATS             $002B00
 #define WINDOW_STACK_BASE           $7E2000
 
 #define BG2_TILE_BUF                $7EA000

snes/nmihook.a65

@@ -86,12 +86,57 @@ nmi_stop:
 
 resethook: ; EMULATION MODE
   .as : .xs
+
+  ; mask interrupt handler call
+  sei
+  ; x stores the count of scanlines
+  ldx #$20
+  ldy #$00
+  ; setup irq on h-position $100.  this value was acquired via manual training
+  lda #$00
+  sta $4207
+  inc
+  sta $4208
+  lda #$10
+  sta $4200
+- wai
+  ; sep seems to set the alignment correctly so an integer value in $4207/$4208 detects h-blank
+  ; there seem to be more distinct phases now.  different padding may change this.
+  sep #$20
+  lda $4212
+  ; ignore lines in v-blank
+  bmi +
+  ; decrement non-vblank scanlines encountered
+  dex
+  ; shift h-blank bit into upper position
+  asl
+  ; no error if not in h-blank
+  bpl +
+  ; increment error counter if h-blank is set (early h-blank)
+  iny
+  ; ack interrupt and check if we have hit all scanlines
++ lda $4211
+  cpx #$00
+  bne -
+  ; stop interrupts and check if we have any errors
+  stz $4200
+  dey
+  bmi +
+  ; perform reset
+  lda #$80
+  sta @MCU_CMD
+- bra -
+  ; clean up state
++ dex
+  stx $4207
+
+resethook_loop:
 - lda $4212
   bpl -
 - lda $4212
   bmi -
   lda $213f
-  bmi resethook
+  bmi resethook_loop
   stz NMI_VECT_DISABLE
   jmp ($fffc)
 

src/cli.c

@@ -437,7 +437,7 @@ void cmd_cheat(void) {
 void cmd_test(void) {
   int i;
   uint8_t databuf[512];
-  fpga_set_snescmd_addr(0);
+  fpga_set_snescmd_addr(SNESCMD_MCU_CMD);
   for(i=0; i<512; i++) {
     databuf[i]=fpga_read_snescmd();
   }

src/config

@@ -1,3 +1,3 @@
-CONFIG_VERSION="1.8.0"
-CONFIG_FWVER=0x01080000
+CONFIG_VERSION="1.8.0-reset"
+CONFIG_FWVER=0x11080000
 CONFIG_MCU_FOSC=12000000

src/snes.c

@@ -257,7 +257,7 @@ void get_selected_name(uint8_t* fn) {
   uint32_t fdaddr;
   char *dot;
   cwdaddr = snes_get_mcu_param();
-  fdaddr = snescmd_readlong(0x08);
+  fdaddr = snescmd_readlong(SNESCMD_MCU_CMD + 0x08);
   printf("cwd addr=%lx  fdaddr=%lx\n", cwdaddr, fdaddr);
   uint16_t count = sram_readstrn(fn, cwdaddr, 256);
   if(count && fn[count-1] != '/') {
@@ -398,12 +398,13 @@ uint16_t snescmd_readstrn(void *buf, uint16_t addr, uint16_t size) {
   return elemcount;
 }
 
+#define BRAM_SIZE (256 - (SNESCMD_MCU_PARAM - SNESCMD_MCU_CMD))
 void snescmd_prepare_nmihook() {
   uint16_t bram_src = sram_readshort(SRAM_MENU_ADDR + MENU_ADDR_BRAM_SRC);
-  uint8_t bram[224];
-  sram_readblock(bram, SRAM_MENU_ADDR + bram_src, 224);
+  uint8_t bram[BRAM_SIZE];
+  sram_readblock(bram, SRAM_MENU_ADDR + bram_src, BRAM_SIZE);
 //  snescmd_writeblock(bram, SNESCMD_HOOKS, 40);
-  snescmd_writeblock(bram, 0x4, 224);
+  snescmd_writeblock(bram, SNESCMD_MCU_PARAM, BRAM_SIZE);
 }
 
 void status_load_to_menu() {

src/snes.h

@@ -75,7 +75,7 @@
 #define SNESCMD_NMI_ENABLE_BUTTONS   (0x2bfc)
 #define SNESCMD_NMI_DISABLE_WRAM     (0x2bfe)
 #define SNESCMD_NMI_WRAM_PATCH_COUNT (0x2bff)
-#define SNESCMD_WRAM_CHEATS          (0x2a90)
+#define SNESCMD_WRAM_CHEATS          (0x2b00)
 
 #define ASM_LDA_IMM      (0xa9)
 #define ASM_STA_ABSLONG  (0x8f)