Tests with SD card emulation

menu.c

@@ -351,7 +351,7 @@ void HandleUI(void)
         /******************************************************************/
 
     case MENU_8BIT_MAIN1: {
-        char entry=1;
+        char entry=0;
 
 	menumask=0;
 	// string at first index is the core name
@@ -362,12 +362,12 @@ void HandleUI(void)
 	// check if there's a file type supported
 	p = user_io_8bit_get_string(1);
 	if(p && strlen(p)) {
-	  menumask = (menumask << 1) | 1;
+	  entry = 1;
+	  menumask = 1;
 	  strcpy(s, " Load *.");
 	  strcat(s, p);
 	  OsdWrite(0, s, menusub==0, 0);
-	} else
-	  OsdWrite(0, " No file I/O", 0,1);
+	}
 
 	// add options as requested by core
 	i = 2;
@@ -430,16 +430,22 @@ void HandleUI(void)
         if (menu)
 	  menustate = MENU_NONE1;
 	if(select) {
-	  p = user_io_8bit_get_string(1+menusub);
+	  char fs_present;
+	  p = user_io_8bit_get_string(1);
+	  fs_present = p && strlen(p);
 
 	  // entry 0 = file selector
-	  if(!menusub) {
+	  if(!menusub && fs_present) {
+	    p = user_io_8bit_get_string(1);
+
 	    // use a local copy of "p" since SelectFile will destroy the buffer behind it
 	    static char ext[4];
 	    strncpy(ext, p, 4);
 	    while(strlen(ext) < 3) strcat(ext, " ");
 	    SelectFile(ext, SCAN_DIR | SCAN_LFN, MENU_8BIT_MAIN_FILE_SELECTED, MENU_8BIT_MAIN1, 1);
 	  } else {
+	    p = user_io_8bit_get_string(menusub + (fs_present?1:2));
+
 	    // determine which status bit is affected
 	    unsigned char mask = 1<<(p[1]-'0');
 	    unsigned char status = user_io_8bit_set_status(0,0);  // 0,0 gets status

user_io.c

@@ -230,6 +230,26 @@ void user_io_eth_send_mac(uint8_t *mac) {
   DisableIO();
 }
 
+// read 8+32 bit sd card status word from FPGA
+uint8_t user_io_sd_get_status(uint32_t *lba) {
+  uint32_t s;
+  uint8_t c; 
+
+  EnableIO();
+  SPI(UIO_GET_SDSTAT);
+  c = SPI(0);
+  s = SPI(0);
+  s = (s<<8) | SPI(0);
+  s = (s<<8) | SPI(0);
+  s = (s<<8) | SPI(0);
+  DisableIO();
+
+  if(lba)
+    *lba = s;
+
+  return c;
+}
+
 // read 32 bit ethernet status word from FPGA
 uint32_t user_io_eth_get_status(void) {
   uint32_t s;
@@ -452,6 +472,15 @@ char *user_io_8bit_get_string(char index) {
   return buffer;
 }    
 
+uint8_t checksum(uint8_t *buffer) {
+  int i;
+  uint8_t sum=0;
+  for(i=0;i<512;i++)
+    sum += buffer[i];
+
+  return sum;
+}
+
 unsigned char user_io_8bit_set_status(unsigned char new_status, unsigned char mask) {
   static unsigned char status = 0;
 
@@ -606,6 +635,96 @@ void user_io_poll() {
   }
 
   if(core_type == CORE_TYPE_8BIT) {
+    unsigned char c = 1, f;
+
+    // check for serial data to be sent
+
+    // check for incoming serial data. this is directly forwarded to the
+    // arm rs232 and mixes with debug output. Useful for debugging only of
+    // e.g. the diagnostic cartridge
+    EnableIO();
+    SPI(UIO_SERIAL_IN);
+    // status byte is 1000000A with A=1 if data is available
+    if((f = SPI(0)) == 0x81) {
+      iprintf("\033[1;36m");
+      
+      // character 0xff is returned if FPGA isn't configured
+      while((f == 0x81) && (c!= 0xff) && (c != 0x00)) {
+	c = SPI(0);
+	if(c != 0xff && c != 0x00) {
+	  iprintf("%c", c);
+	  f = SPI(0);
+	}
+      }
+      iprintf("\033[0m");
+    }
+    DisableIO();
+    
+    // sd card emulation
+    {
+      static char buffer[512];
+      static uint32_t buffer_lba = 0xffffffff;
+      static uint8_t buffer_chk;
+      uint32_t lba;
+      uint8_t c = user_io_sd_get_status(&lba);
+
+      // valid sd commands start with "5x" to avoid problems with
+      // cores that don't implement this command
+      if((c & 0xf0) == 0x50) {
+	if((c & 0x03) == 0x01) {
+	  //	  iprintf("%s sector read %ld\n", (c&0x04)?"SDHC":"SD", lba);
+
+	  // sector read
+	  // read sector from sd card if it is not already present in
+	  // the buffer
+	  if(buffer_lba != lba) {
+	    DISKLED_ON;
+	    if(MMC_Read(lba, buffer)) {
+	      buffer_lba = lba;
+	      buffer_chk = checksum(buffer);
+	    }
+	    DISKLED_OFF;
+	  }
+
+#if 0
+	  // verify by re-read
+	  { char buf2[512];
+	    if(MMC_Read(lba, buf2)) {
+	      if(memcmp(buffer, buf2, 512) != 0)
+		iprintf("verify error lba %d\n", lba);
+	    } else
+	      iprintf("read error lba %d\n", lba);
+	  }
+#endif
+
+	  if(buffer_lba == lba) {
+	    // data is now stored in buffer. send it to fpga
+	    EnableIO();
+	    SPI(UIO_SECTOR_RD);
+	    SPI_block_write(buffer);
+	    SPI(buffer_chk);
+	    DisableIO();
+
+	    // the end of this transfer acknowledges the FPGA internal
+	    // sd card emulation
+
+	    // read status byte incl the checksum verification bit
+	    c = user_io_sd_get_status(NULL);
+	    if(!(c & 0x08)) iprintf("checksum failure in lbs %d\n", lba);
+	  }
+
+	  // just load the next sector now, so it may be prefetched
+	  // for the next request already
+	  DISKLED_ON;
+	  if(MMC_Read(lba+1, buffer)) {
+	    buffer_lba = lba+1;
+	    buffer_chk = checksum(buffer);
+	  }
+	  DISKLED_OFF;
+	}
+      }
+    }
+
     // raw sector io for the atari800 core which include a full
     // file system driver usually implemented using a second cpu
     static unsigned long bit8_status = 0;

user_io.h

@@ -41,6 +41,8 @@
 // codes as currently used by 8bit only
 #define UIO_GET_STRING  0x14
 #define UIO_SET_STATUS  0x15
+#define UIO_GET_SDSTAT  0x16  // read status of sd card emulation
+#define UIO_SECTOR_RD   0x17
 
 // codes as used by 8bit (atari 800, zx81) via SS2
 #define UIO_GET_STATUS  0x50