disk.c

eCos操作系统源码

//==========================================================================
//
//      io/disk/disk.c
//
//      High level disk driver
//
//==========================================================================
//####ECOSGPLCOPYRIGHTBEGIN####
// -------------------------------------------
// This file is part of eCos, the Embedded Configurable Operating System.
// Copyright (C) 2003 Savin Zlobec 
//
// 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.
//
// -------------------------------------------
//####ECOSGPLCOPYRIGHTEND####
//==========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):     savin 
// Date:          2003-06-10
// Purpose:       Top level disk driver
// Description: 
//
//####DESCRIPTIONEND####
//
//==========================================================================

#include <pkgconf/io.h>
#include <pkgconf/io_disk.h>

#include <cyg/io/io.h>
#include <cyg/io/devtab.h>
#include <cyg/io/disk.h>
#include <cyg/infra/cyg_ass.h>      // assertion support
#include <cyg/infra/diag.h>         // diagnostic output

#include <stdlib.h>  // malloc 

// ---------------------------------------------------------------------------

//#define DEBUG 1

#ifdef DEBUG
# define D(_args_) diag_printf _args_
#else
# define D(_args_)
#endif

// ---------------------------------------------------------------------------

// Master Boot Record defines
#define MBR_SIG_ADDR  0x1FE   // signature address 
#define MBR_SIG_BYTE0 0x55    // signature first byte value
#define MBR_SIG_BYTE1 0xAA    // signature second byte value
#define MBR_PART_ADDR 0x1BE   // first partition address
#define MBR_PART_SIZE 0x10    // partition size
#define MBR_PART_NUM  4       // number of partitions

// Get cylinders, heads and sectors from data (MBR partition format)
#define READ_CHS(_data_, _c_, _h_, _s_)                     \
    do {                                                    \
        _h_ = (*((cyg_uint8 *)_data_));                     \
        _s_ = (*(((cyg_uint8 *)_data_)+1) &  0x3F);         \
        _c_ = (*(((cyg_uint8 *)_data_)+1) & ~0x3F) << 2 |   \
              (*(((cyg_uint8 *)_data_)+2));                 \
    } while (0)

// Get double word from data (MBR partition format)
#define READ_DWORD(_data_, _val_)                           \
    do {                                                    \
        _val_ = *((cyg_uint8 *)_data_)           |          \
                *(((cyg_uint8 *)_data_)+1) << 8  |          \
                *(((cyg_uint8 *)_data_)+2) << 16 |          \
                *(((cyg_uint8 *)_data_)+3) << 24;           \
    } while (0)

// Convert cylinders, heads and sectors to LBA sectors 
#define CHS_TO_LBA(_info_, _c_, _h_, _s_, _lba_) \
    (_lba_=(((_c_)*(_info_)->heads_num+(_h_))*(_info_)->sectors_num)+(_s_)-1)
    
// ---------------------------------------------------------------------------

static Cyg_ErrNo disk_bread(cyg_io_handle_t  handle, 
                            void            *buf, 
                            cyg_uint32      *len, 
                            cyg_uint32       pos);

static Cyg_ErrNo disk_bwrite(cyg_io_handle_t  handle, 
                             const void      *buf, 
                             cyg_uint32      *len, 
                             cyg_uint32       pos);

static Cyg_ErrNo disk_select(cyg_io_handle_t handle, 
                             cyg_uint32      which, 
                             CYG_ADDRWORD    info);

static Cyg_ErrNo disk_get_config(cyg_io_handle_t  handle, 
                                 cyg_uint32       key, 
                                 void            *buf, 
                                 cyg_uint32      *len);

static Cyg_ErrNo disk_set_config(cyg_io_handle_t  handle, 
                                 cyg_uint32       key, 
                                 const void      *buf, 
                                 cyg_uint32      *len);

BLOCK_DEVIO_TABLE(cyg_io_disk_devio,
                  disk_bwrite,
                  disk_bread,
                  disk_select,
                  disk_get_config,
                  disk_set_config
);

static cyg_bool disk_init(struct cyg_devtab_entry *tab);

static Cyg_ErrNo disk_connected(struct cyg_devtab_entry *tab,
                                cyg_disk_identify_t     *ident);

static Cyg_ErrNo disk_disconnected(struct cyg_devtab_entry *tab);

static Cyg_ErrNo disk_lookup(struct cyg_devtab_entry **tab,
                             struct cyg_devtab_entry  *sub_tab,
                             const char               *name);

DISK_CALLBACKS(cyg_io_disk_callbacks, 
               disk_init,
               disk_connected,
               disk_disconnected,
               disk_lookup
); 

// ---------------------------------------------------------------------------

//
// Read partition from data
// 
static void 
read_partition(cyg_uint8            *data,
               cyg_disk_info_t      *info,
               cyg_disk_partition_t *part)
{
    cyg_uint16 c, h, s;

    part->type  = data[4];
    part->state = data[0];

    READ_CHS(&data[1], c, h, s);
    CHS_TO_LBA(&info->ident, c, h, s, part->start);

    READ_CHS(&data[5], c, h, s);
    CHS_TO_LBA(&info->ident, c, h, s, part->end);

    READ_DWORD(&data[12], part->size);
}

//
// Read Master Boot Record (partitions)
//
static Cyg_ErrNo 
read_mbr(disk_channel *chan)
{
    cyg_disk_info_t *info = chan->info;
    disk_funs       *funs = chan->funs;
    cyg_uint8 buf[512];
    Cyg_ErrNo res = ENOERR;
    int i;
 
    for (i = 0; i < MBR_PART_NUM; i++)
        info->partitions[i].type = 0x00;    
   
    res = (funs->read)(chan, (void *)buf, 512, 0);
    if (ENOERR != res)
        return res;

    if (MBR_SIG_BYTE0 == buf[MBR_SIG_ADDR+0] && MBR_SIG_BYTE1 == buf[MBR_SIG_ADDR+1])
    {
        D(("disk MBR found\n")); 
 
        for (i = 0; i < MBR_PART_NUM; i++)
        {
            cyg_disk_partition_t *part = &info->partitions[i];
            
            read_partition(&buf[MBR_PART_ADDR+MBR_PART_SIZE*i], info, part); 
#ifdef DEBUG
            if (0x00 != part->type)
            {
                D(("\ndisk MBR partition %d:\n", i));
                D(("      type  = %02X\n", part->type));
                D(("      state = %02X\n", part->state));
                D(("      start = %d\n",   part->start));
                D(("      end   = %d\n",   part->end));
                D(("      size  = %d\n\n", part->size));
            }
#endif
        } 
    }
    return ENOERR;
}

static cyg_bool 
disk_init(struct cyg_devtab_entry *tab)
{
    disk_channel    *chan = (disk_channel *) tab->priv;
    cyg_disk_info_t *info = chan->info;
    int i;

    if (!chan->init)
    {
        info->connected = false;

        // clear devices array (one per partition)
        // and partition data
        for (i = 0; i < MBR_PART_NUM; i++)
        {
            info->devs[i] = (cyg_addrword_t) 0;
            info->partitions[i].type = 0x00;
        }
        
        chan->init = true;
    }
    return true;
}

static Cyg_ErrNo
disk_connected(struct cyg_devtab_entry *tab,
               cyg_disk_identify_t     *ident)
{
    disk_channel    *chan = (disk_channel *) tab->priv;
    cyg_disk_info_t *info = chan->info;
    Cyg_ErrNo res = ENOERR;
 
    if (!chan->init)
        return -EINVAL;
    
    info->ident      = *ident;
    info->block_size = 512;
    info->blocks_num = ident->lba_sectors_num;
 
    D(("disk connected\n")); 
    D(("    serial       = '%s'\n", ident->serial)); 
    D(("    firmware rev = '%s'\n", ident->firmware_rev)); 
    D(("    model num    = '%s'\n", ident->model_num)); 
    D(("    block_size   = %d\n",   info->block_size));
    D(("    blocks_num   = %d\n",   info->blocks_num));

    if (chan->mbr_support)
    {    
        // read disk master boot record
        res = read_mbr(chan);
    }

    if (ENOERR == res)
    {    
        // now declare that we are connected
        info->connected = true;
        chan->valid     = true; 
    }
    return res;
}

static Cyg_ErrNo
disk_disconnected(struct cyg_devtab_entry *tab)
{
    disk_channel    *chan = (disk_channel *) tab->priv;
    cyg_disk_info_t *info = chan->info;
    int i;

    if (!chan->init)