USBMSD example using a file system located in RAM

Fork of RAM_DISK by Samuel Mokrani

USBMSD_Ram.cpp

Committer:
samux
Date:
2013-05-16
Revision:
1:3d0c421fe52b
Parent:
0:ba333853266b
Child:
2:2c92946b6568

File content as of revision 1:3d0c421fe52b:

/* mbed USBMSD_Ram Library
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "USBMSD_Ram.h"

typedef struct sector {
    const char * sect;
    unsigned int length;
} SECTOR;

#define LSByte(x) (x & 0xff)
#define MSByte(x) ((x >> 8) & 0xff)

const char mbr[] = {
    //sector 0: boot sector
    0xEB,0x3C,0x90,0x4D,0x53,0x44,0x4F,0x53,0x35,0x2E,0x30,    0x00,0x02,/*bytes per sector: 512*/   0x01, /*sectors per cluster*/ 0x01,0x00,/*number of reserved sector*/
    0x01, /* number of FATs*/ 0x10,0x00, /*Maximum number of root directory entries: 16*/ LSByte(NB_SECTORS),MSByte(NB_SECTORS), /*Total sector count*/ 0xF0,  0x01,0x00,/*sectors per FAT: 1*/  0x01,0x00,/*Sectors per track*/  0x01,0x00, /*Number of heads*/  0x00,0x00,0x00,0x00,
    0x00,0x01,0x00,0x00,0x00,0x00,  0x29, /*boot signature*/ 0x74,0x19,0x02,0x27, /*volume ID*/ 'M','b','e','d',' ',
    'U','S','B',' ',' ',' ', /*volume label: Mbed USB*/     0x46,0x41,0x54,0x31,0x32,0x20,0x20,0x20,0x33,0xC9,
    0x8E,0xD1,0xBC,0xF0,0x7B,0x8E,0xD9,0xB8,0x00,0x20,0x8E,0xC0,0xFC,0xBD,0x00,0x7C,
    0x38,0x4E,0x24,0x7D,0x24,0x8B,0xC1,0x99,0xE8,0x3C,0x01,0x72,0x1C,0x83,0xEB,0x3A,
    0x66,0xA1,0x1C,0x7C,0x26,0x66,0x3B,0x07,0x26,0x8A,0x57,0xFC,0x75,0x06,0x80,0xCA,
    0x02,0x88,0x56,0x02,0x80,0xC3,0x10,0x73,0xEB,0x33,0xC9,0x8A,0x46,0x10,0x98,0xF7,
    0x66,0x16,0x03,0x46,0x1C,0x13,0x56,0x1E,0x03,0x46,0x0E,0x13,0xD1,0x8B,0x76,0x11,
    0x60,0x89,0x46,0xFC,0x89,0x56,0xFE,0xB8,0x20,0x00,0xF7,0xE6,0x8B,0x5E,0x0B,0x03,
    0xC3,0x48,0xF7,0xF3,0x01,0x46,0xFC,0x11,0x4E,0xFE,0x61,0xBF,0x00,0x00,0xE8,0xE6,
    0x00,0x72,0x39,0x26,0x38,0x2D,0x74,0x17,0x60,0xB1,0x0B,0xBE,0xA1,0x7D,0xF3,0xA6,
    0x61,0x74,0x32,0x4E,0x74,0x09,0x83,0xC7,0x20,0x3B,0xFB,0x72,0xE6,0xEB,0xDC,0xA0,
    0xFB,0x7D,0xB4,0x7D,0x8B,0xF0,0xAC,0x98,0x40,0x74,0x0C,0x48,0x74,0x13,0xB4,0x0E,
    0xBB,0x07,0x00,0xCD,0x10,0xEB,0xEF,0xA0,0xFD,0x7D,0xEB,0xE6,0xA0,0xFC,0x7D,0xEB,
    0xE1,0xCD,0x16,0xCD,0x19,0x26,0x8B,0x55,0x1A,0x52,0xB0,0x01,0xBB,0x00,0x00,0xE8,
    0x3B,0x00,0x72,0xE8,0x5B,0x8A,0x56,0x24,0xBE,0x0B,0x7C,0x8B,0xFC,0xC7,0x46,0xF0,
    0x3D,0x7D,0xC7,0x46,0xF4,0x29,0x7D,0x8C,0xD9,0x89,0x4E,0xF2,0x89,0x4E,0xF6,0xC6,
    0x06,0x96,0x7D,0xCB,0xEA,0x03,0x00,0x00,0x20,0x0F,0xB6,0xC8,0x66,0x8B,0x46,0xF8,
    0x66,0x03,0x46,0x1C,0x66,0x8B,0xD0,0x66,0xC1,0xEA,0x10,0xEB,0x5E,0x0F,0xB6,0xC8,
    0x4A,0x4A,0x8A,0x46,0x0D,0x32,0xE4,0xF7,0xE2,0x03,0x46,0xFC,0x13,0x56,0xFE,0xEB,
    0x4A,0x52,0x50,0x06,0x53,0x6A,0x01,0x6A,0x10,0x91,0x8B,0x46,0x18,0x96,0x92,0x33,
    0xD2,0xF7,0xF6,0x91,0xF7,0xF6,0x42,0x87,0xCA,0xF7,0x76,0x1A,0x8A,0xF2,0x8A,0xE8,
    0xC0,0xCC,0x02,0x0A,0xCC,0xB8,0x01,0x02,0x80,0x7E,0x02,0x0E,0x75,0x04,0xB4,0x42,
    0x8B,0xF4,0x8A,0x56,0x24,0xCD,0x13,0x61,0x61,0x72,0x0B,0x40,0x75,0x01,0x42,0x03,
    0x5E,0x0B,0x49,0x75,0x06,0xF8,0xC3,0x41,0xBB,0x00,0x00,0x60,0x66,0x6A,0x00,0xEB,
    0xB0,0x4E,0x54,0x4C,0x44,0x52,0x20,0x20,0x20,0x20,0x20,0x20,0x0D,0x0A,0x52,0x65,
    0x6D,0x6F,0x76,0x65,0x20,0x64,0x69,0x73,0x6B,0x73,0x20,0x6F,0x72,0x20,0x6F,0x74,
    0x68,0x65,0x72,0x20,0x6D,0x65,0x64,0x69,0x61,0x2E,0xFF,0x0D,0x0A,0x44,0x69,0x73,
    0x6B,0x20,0x65,0x72,0x72,0x6F,0x72,0xFF,0x0D,0x0A,0x50,0x72,0x65,0x73,0x73,0x20,
    0x61,0x6E,0x79,0x20,0x6B,0x65,0x79,0x20,0x74,0x6F,0x20,0x72,0x65,0x73,0x74,0x61,
    0x72,0x74,0x0D,0x0A,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xAC,0xCB,0xD8,0x55,0xAA,
};

const char fat[] = { 0xF8,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x0F };

const char root_dir[] = {
    //sector 3: root directory
    //entry 1
    'M','b','e','d',' ','U','S','B',' ',' ',' ',   0x28,0x00,0x00,0x00,0x00,
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    //entry 2
    'R','E','A','D','M','E',0x20,0x20,'T','X','T', /*readme.txt*/ 0x20,0x00,0x00,0x00,0x00,
    0x21,0x00,0xBB,0x32,0x00,0x00,   0xDC,0x83,/*hour/min/doublesec*/  0x6A,0x3F,/*year/month/day*/  0x02,0x00, /*starting cluster*/ 0x1e,0x00,0x00,0x00, /*size*/
};

const char data[] = {
    //sector 4: data
    'H','e','l','l','o',' ','f','r','o','m',' ','M','b','e','d','!',
    '\r','\n','U','S','B',' ','M','S','D',' ','d','e','m','o',0x00,0x00
};

//3 sectors
SECTOR sectors[4] = {
    {mbr , 512},
    {fat, 8},
    {root_dir, 4*16},

    // contains readme.txt
    {data, 2*16}
};

USBMSD_Ram::USBMSD_Ram()  {
    //no init
    _status = 0x01;
    memset(disk_image, 0, 512*4);
    for (uint8_t i = 0; i < 4; i++) {
        memcpy(disk_image + 512*i, sectors[i].sect, sectors[i].length);
    }
    connect();
}

int USBMSD_Ram::disk_initialize() {
    // OK
    _status = 0x00;
    return 0;
}

int USBMSD_Ram::disk_write(const uint8_t * buffer, uint64_t block_number) { 
    memcpy(disk_image + block_number*512, buffer, 512);
    return 0;    
}

int USBMSD_Ram::disk_read(uint8_t * buffer, uint64_t block_number) {
    memcpy(buffer, disk_image + block_number*512, 512);
    return 0;
}

int USBMSD_Ram::disk_status() { return _status; }
int USBMSD_Ram::disk_sync() { return 0; }
uint64_t USBMSD_Ram::disk_sectors() { return NB_SECTORS; }
uint64_t USBMSD_Ram::disk_size() { return NB_SECTORS*512;}