o add snes diskio interface

snes/fatfstest/diskio.c

@@ -0,0 +1,165 @@
+
+#include "integer.h"
+#include "diskio.h"
+#include "config.h"
+#include "data.h"
+
+static 
+DSTATUS Stat = STA_NOINIT;  /* Disk status */
+
+
+/* Interface
+** Scratch Buffer
+addr        3 byte            
+size        1 byte
+
+** Call Interface
+cmd         1 byte
+sector      4 bytes
+count       1 byte
+return      1 byte
+
+** Commands
+    * disk_init
+    * disk_read
+    * disk_write
+*/ 
+
+/*-----------------------------------------------------------------------*/
+/* Initialize Disk Drive                                                 */
+/*-----------------------------------------------------------------------*/
+
+#include <string.h>
+
+#define IMAGE_NAME "disk00.vfat"
+
+BYTE  *image_addr;
+
+DSTATUS disk_initialize (BYTE drv) {
+    
+    byte retval;
+    if (drv) return STA_NOINIT;             /* Supports only single drive */
+
+
+    Stat |= STA_NOINIT;
+    *(byte*) MMIO_RETVAL = STA_VOID;
+    *(byte*) MMIO_CMD = CMD_INIT;    
+    while(*(byte*) MMIO_RETVAL == STA_VOID);
+    retval = *(byte*) MMIO_RETVAL;
+    Stat &= ~retval;                    /* When device goes ready, clear STA_NOINIT */
+    return Stat;
+}
+
+
+/*-----------------------------------------------------------------------*/
+/* Return Disk Status                                                    */
+/*-----------------------------------------------------------------------*/
+
+DSTATUS disk_status (BYTE drv){
+    if (drv) return STA_NOINIT;     /* Supports only single drive */
+    return Stat;
+}
+
+
+/*-----------------------------------------------------------------------*/
+/* Read Sector(s)                                                        */
+/*-----------------------------------------------------------------------*/
+
+DRESULT disk_read (
+    BYTE drv,       /* Physical drive nmuber (0) */
+    BYTE *buff,     /* Data buffer to store read data */
+    DWORD sector,   /* Sector number (LBA) */
+    BYTE count      /* Sector count (1..255) */
+)
+{
+    DWORD offset;
+    INT size;
+    byte retval;
+    word i;
+    for (i=0;i<(count*512);i++)
+        *(byte*)(SHARED_ADDR+i) = buff[i];
+    
+    if (drv || !count) return RES_PARERR;
+    if (Stat & STA_NOINIT) return RES_NOTRDY;
+
+    *(byte*) MMIO_RETVAL = STA_VOID;
+    *(byte*) MMIO_CMD = CMD_READ;    
+    
+    *(byte*) MMIO_SECTOR01 = (sector >> 24) & 0xff;    
+    *(byte*) MMIO_SECTOR02 = (sector >> 16) & 0xff;    
+    *(byte*) MMIO_SECTOR03 = (sector >> 8) & 0xff;
+    *(byte*) MMIO_SECTOR04 = (sector >> 8) & 0xff;
+    
+    *(byte*) MMIO_COUNT = count;    
+    
+    while(*(byte*) MMIO_RETVAL == STA_VOID);
+    retval = *(byte*) MMIO_RETVAL;
+    
+
+    return retval;
+}
+
+/*-----------------------------------------------------------------------*/
+/* Write Sector(s)                                                       */
+/*-----------------------------------------------------------------------*/
+
+#if _READONLY == 0
+DRESULT disk_write (
+    BYTE drv,           /* Physical drive nmuber (0) */
+    const BYTE *buff,   /* Data to be written */
+    DWORD sector,       /* Sector number (LBA) */
+    BYTE count          /* Sector count (1..255) */
+)
+{
+    DWORD offset;
+    INT size;
+
+    if (drv || !count) return RES_PARERR;
+    if (Stat & STA_NOINIT) return RES_NOTRDY;
+
+    offset = sector  * 512;
+    size = count * 512;
+    return RES_OK;
+}
+#endif /* _READONLY */
+
+/*-----------------------------------------------------------------------*/
+/* Miscellaneous Functions                                               */
+/*-----------------------------------------------------------------------*/
+
+#if _USE_IOCTL != 0
+DRESULT disk_ioctl (
+    BYTE drv,       /* Physical drive nmuber (0) */
+    BYTE ctrl,      /* Control code */
+    void *buff      /* Buffer to send/receive data block */
+)
+{
+    BYTE n, w, ofs, dl, dh, *ptr = (BYTE*)buff;
+
+
+    if (drv) return RES_PARERR;
+    if (Stat & STA_NOINIT) return RES_NOTRDY;
+
+    switch (ctrl) {
+        case GET_SECTOR_COUNT : /* Get number of sectors on the disk (DWORD) */
+            ofs = 60; w = 2; n = 0;
+            break;
+
+        case GET_SECTOR_SIZE :  /* Get sectors on the disk (WORD) */
+            *(WORD*)buff = 512;
+            return RES_OK;
+
+        case GET_BLOCK_SIZE :   /* Get erase block size in sectors (DWORD) */
+            *(DWORD*)buff = 32;
+            return RES_OK;
+
+        default:
+            return RES_PARERR;
+    }
+    return RES_OK;
+}
+#endif /* _USE_IOCTL != 0 */
+
+
+
+