disk.h

redboot 源代码

//==========================================================================
//
//      disk.h
//
//      Stand-alone disk support for RedBoot
//
//==========================================================================
//####ECOSGPLCOPYRIGHTBEGIN####
// -------------------------------------------
// This file is part of eCos, the Embedded Configurable Operating System.
// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
//
// eCos is free software; you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 2 or (at your option) any later version.
//
// eCos is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
// for more details.
//
// You should have received a copy of the GNU General Public License along
// with eCos; if not, write to the Free Software Foundation, Inc.,
// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
//
// As a special exception, if other files instantiate templates or use macros
// or inline functions from this file, or you compile this file and link it
// with other works to produce a work based on this file, this file does not
// by itself cause the resulting work to be covered by the GNU General Public
// License. However the source code for this file must still be made available
// in accordance with section (3) of the GNU General Public License.
//
// This exception does not invalidate any other reasons why a work based on
// this file might be covered by the GNU General Public License.
//
// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.
// at http://sources.redhat.com/ecos/ecos-license/
// -------------------------------------------
//####ECOSGPLCOPYRIGHTEND####
//==========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):    msalter
// Contributors: msalter
// Date:         2001-07-02
// Purpose:      
// Description:  
//              
// This code is part of RedBoot (tm).
//
//####DESCRIPTIONEND####
//
//==========================================================================

#ifndef CYGONCE_REDBOOT_DISK_H
#define CYGONCE_REDBOOT_DISK_H

#define SECTOR_SIZE 512

// Convenience macros to access disk/filesystem info which may
// be stored in a fixed endian format.

#define __SWAB16(x) \
    ((((x) & 0xFF) << 8) | (((x) >> 8) & 0xFF))

#define __SWAB32(x)         \
   ((((x) & 0xff) << 24)   |  \
    (((x) & 0xff00) <<  8) |  \
    (((x) >> 8) & 0xff00)  |  \
    (((x) >> 24) & 0xff))

#if (CYG_BYTEORDER == CYG_MSBFIRST)
#define SWAB_LE16(x) __SWAB16(x)
#define SWAB_LE32(x) __SWAB32(x)
#define SWAB_BE16(x) (x)
#define SWAB_BE32(x) (x)
#else
#define SWAB_LE16(x) (x)
#define SWAB_LE32(x) (x)
#define SWAB_BE16(x) __SWAB16(x)
#define SWAB_BE32(x) __SWAB32(x)
#endif

struct partition;

// filesystem interface
typedef struct fs_funs {
    // Load a file into memory.
    void * (*open)(struct partition *p, const char *path);
    int    (*read)(void *fp, char *buf, cyg_uint32 nbytes);
} fs_funs_t;

struct disk;

typedef struct partition {
    struct disk *disk;
    fs_funs_t   *funs;
    cyg_uint32	start_sector;	// first sector in partition
    cyg_uint32	nr_sectors;	// number of sectors in partition
    cyg_uint8   systype;        // FAT12, FAT16, Linux, etc.
    cyg_uint8   bootflag;       // not really used...
} partition_t;

// System types
#define SYSTYPE_FAT12        0x01
#define SYSTYPE_FAT16_32M    0x04
#define SYSTYPE_EXTENDED     0x05
#define SYSTYPE_FAT16        0x06
#define SYSTYPE_LINUX_SWAP   0x82
#define SYSTYPE_LINUX        0x83

typedef struct disk_funs {
    int  (*read)(struct disk *d,
                 cyg_uint32  start_sector,
                 cyg_uint32  *buf,
                 cyg_uint8   nr_sectors);
} disk_funs_t;


typedef struct disk {
    disk_funs_t *funs;		// Disk driver functions
    void        *private;  	// Whatever is needed by disk functions
    cyg_uint32  nr_sectors;	// Total disk size in sectors
    short       kind;   	// IDE_HD, IDE_CDROM, SCSI_HD, etc
    short       index;  	// index within specific kind
    partition_t partitions[CYGNUM_REDBOOT_MAX_PARTITIONS];
} disk_t;

#define DISK_READ(d,s,p,n) ((d)->funs->read)((d),(s),(p),(n))
#define PARTITION_READ(part,s,p,n) \
    DISK_READ((part)->disk, (s) + (part)->start_sector, (p), (n))

// Kinds of disks
#define DISK_IDE_HD     1
#define DISK_IDE_CDROM  2
#define DISK_FLOPPY     3

// DOS partition table as laid out in the MBR
//
struct mbr_partition {
    cyg_uint8  boot_ind;	// 0x80 == active
    cyg_uint8  head;
    cyg_uint8  sector;
    cyg_uint8  cyl;
    cyg_uint8  sys_ind;		// partition type
    cyg_uint8  end_head;
    cyg_uint8  end_sector;
    cyg_uint8  end_cyl;
    cyg_uint8  start_sect[4];	// starting sector counting from 0
    cyg_uint8  nr_sects[4];	// number of sectors in partition
};

#define MBR_PTABLE_OFFSET 0x1be
#define MBR_MAGIC_OFFSET  0x1fe
#define MBR_MAGIC         0xaa55

// Add a disk to the disk table.
// Return zero if no more room in table.
//
externC int disk_register(disk_t *disk);


#define diskerr_badname   -1
#define diskerr_partition -2
#define diskerr_open      -3
#define diskerr_read      -4

externC int   disk_stream_open(connection_info_t *info, int *err);    
externC void  disk_stream_close(int *err);    
externC int   disk_stream_read(char *buf, int size, int *err);    
externC char *disk_error(int err);

#endif // CYGONCE_REDBOOT_DISK_H