source: thomson/code/C/HxCHost/pff/diskio.c@ 645c148

/*-----------------------------------------------------------------------*/
/* Low level disk I/O module skeleton for Petit FatFs (C)ChaN, 2009      */
/* Driver for MO5/TO8 HxC floppy emulator direct access
 * Copyright 2011, Adrien Destugues <pulkomandy@pulkomandy.ath.cx>
-------------------------------------------------------------------------*/

#include "diskio.h"

#include "../macros.h"

/*******/
extern unsigned char* secbuf;
extern unsigned char mark[];
/*******/

/*-----------------------------------------------------------------------*/
/* Initialize Disk Drive                                                 */
/*-----------------------------------------------------------------------*/

DSTATUS disk_initialize (void)
{
        // Enter host mode
        seek();

        // Read header to check everything is ok
        read(255, 0, secbuf);

        // Check for HxCFEDA marker
        if (*(long*)(mark) != *(long*)(secbuf))
                return STA_NOINIT;
        if (*(long*)(mark+4) != *(long*)(secbuf+4))
                return STA_NOINIT;
        return 0;
}



/*-----------------------------------------------------------------------*/
/* Read Partial Sector                                                   */
/*-----------------------------------------------------------------------*/

DRESULT disk_readp (
        BYTE* dest,                     /* Pointer to the destination object */
        DWORD sector,           /* Sector number (LBA) */
        WORD sofs,                      /* Offset in the sector */
        WORD count                      /* Byte count (bit15:destination) */
)
{
        static DWORD prevsec = -1;
        // TODO implement caching system
        //  * If sector is reachable with current LBA, don't change it

        printhex(sector>>24);
        printhex(sector>>16);
        printhex(sector>>8);
        printhex(sector);
        mon_putc(' ');

        if (prevsec != sector)
        {

                // Set LBA address
                int j = 8;
                mark[j++] = 1;
                mark[j++] = sector;
                mark[j++] = (sector>>8);
                mark[j++] = (sector>>16);
                mark[j++] = (sector>>24);
                mark[j++] = 0; // Write disabled
                mark[j++] = 6; // Sector count
                for(; j <512; j++) mark[j] = 0;
                write(255,0,mark);

                prevsec = sector;
                // Read sector
                read(255,1,secbuf);
        }

        // Copy useful bytes to dest.
        sofs += (int)(secbuf);
        for(int j = 0; j <count;++j)
        {
            *(char*)(dest+j) = *(char*)(j+sofs);
        }

        return RES_OK;
}



/*-----------------------------------------------------------------------*/
/* Write Partial Sector                                                  */
/*-----------------------------------------------------------------------*/

DRESULT disk_writep (
        const BYTE* buff,/* Pointer to the data to be written, NULL:Initiate/Finalize write operation */
        DWORD sc                /* Sector number (LBA) or Number of bytes to send */
)
{
        // TODO write it
        // Beware of using the sector buffer, read is doing caching there...
        DRESULT res = RES_ERROR;


        if (!buff) {
                if (sc) {

                        // Initiate write process

                } else {

                        // Finalize write process

                }
        } else {

                // Send data to the disk

        }

        return res;
}