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lxdream.org :: lxdream/src/gdrom/linux.c
lxdream 0.9.1
released Jun 29
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filename src/gdrom/linux.c
changeset 342:850502f0e8de
prev259:7c6881790cc2
next353:b8569afb53fc
author nkeynes
date Wed Jan 31 10:58:42 2007 +0000 (14 years ago)
permissions -rw-r--r--
last change Refactor gdrom module to be more conducive to real device support
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     1 /**
     2  * $Id: linux.c,v 1.3 2007-01-31 10:58:42 nkeynes Exp $
     3  *
     4  * Linux cd-rom device driver. 
     5  *
     6  * Copyright (c) 2005 Nathan Keynes.
     7  *
     8  * This program is free software; you can redistribute it and/or modify
     9  * it under the terms of the GNU General Public License as published by
    10  * the Free Software Foundation; either version 2 of the License, or
    11  * (at your option) any later version.
    12  *
    13  * This program is distributed in the hope that it will be useful,
    14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
    15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    16  * GNU General Public License for more details.
    17  */
    18 #include <stdlib.h>
    19 #include <stdio.h>
    20 #include <string.h>
    21 #include <errno.h>
    22 #include <linux/cdrom.h>
    23 #include <sys/stat.h>
    24 #include <sys/ioctl.h>
    26 #include "gdrom/gdrom.h"
    27 #include "gdrom/packet.h"
    28 #include "dream.h"
    30 #define MAXTOCENTRIES 600  /* This is a fairly generous overestimate really */
    31 #define MAXTOCSIZE 4 + (MAXTOCENTRIES*11)
    32 #define MAX_SECTORS_PER_CALL 1
    34 #define MSFTOLBA( m,s,f ) (f + (s*CD_FRAMES) + (m*CD_FRAMES*CD_SECS))
    36 static uint32_t inline lbatomsf( uint32_t lba ) {
    37     union cdrom_addr addr;
    38     lba = lba + CD_MSF_OFFSET;
    39     addr.msf.frame = lba % CD_FRAMES;
    40     int seconds = lba / CD_FRAMES;
    41     addr.msf.second = seconds % CD_SECS;
    42     addr.msf.minute = seconds / CD_SECS;
    43     return addr.lba;
    44 }
    46 #define LBATOMSF( lba ) lbatomsf(lba)
    49 static gboolean linux_image_is_valid( FILE *f );
    50 static gdrom_disc_t linux_open_device( const gchar *filename, FILE *f );
    51 static gdrom_error_t linux_read_disc_toc( gdrom_image_t disc );
    52 static gdrom_error_t linux_read_sector( gdrom_disc_t disc, uint32_t sector,
    53 					int mode, char *buf, uint32_t *length );
    54 static gdrom_error_t linux_send_command( int fd, char *cmd, char *buffer, size_t *buflen,
    55 					 int direction );
    58 struct gdrom_image_class linux_device_class = { "Linux", NULL,
    59 					     linux_image_is_valid, linux_open_device };
    61 static gboolean linux_image_is_valid( FILE *f )
    62 {
    63     struct stat st;
    64     struct cdrom_tochdr tochdr;
    66     if( fstat(fileno(f), &st) == -1 ) {
    67 	return FALSE; /* can't stat device? */
    68     }
    69     if( !S_ISBLK(st.st_mode) ) {
    70 	return FALSE; /* Not a block device */
    71     }
    73     if( ioctl(fileno(f), CDROMREADTOCHDR, &tochdr) == -1 ) {
    74 	/* Quick check that this is really a CD */
    75 	return FALSE;
    76     }
    78     return TRUE;
    79 }
    81 static gdrom_disc_t linux_open_device( const gchar *filename, FILE *f ) 
    82 {
    83     gdrom_disc_t disc;
    84     int fd = fileno(f);
    86     disc = gdrom_image_new(f);
    87     if( disc == NULL ) {
    88 	ERROR("Unable to allocate memory!");
    89 	return NULL;
    90     }
    92     gdrom_error_t status = linux_read_disc_toc( (gdrom_image_t)disc );
    93     if( status != 0 ) {
    94 	disc->close(disc);
    95 	if( status == 0xFFFF ) {
    96 	    ERROR("Unable to load disc table of contents (%s)", strerror(errno));
    97 	} else {
    98 	    ERROR("Unable to load disc table of contents (sense %d,%d)",
    99 		  status &0xFF, status >> 8 );
   100 	}
   101 	return NULL;
   102     }
   103     disc->read_sector = linux_read_sector;
   104     ((gdrom_image_t)disc)->disc_type = IDE_DISC_CDROM;
   105     return disc;
   106 }
   108 /**
   109  * Read the full table of contents into the disc from the device.
   110  */
   111 static gdrom_error_t linux_read_disc_toc( gdrom_image_t disc )
   112 {
   113     int fd = fileno(disc->file);
   114     unsigned char buf[MAXTOCSIZE];
   115     int buflen = sizeof(buf);
   116     char cmd[12] = { 0x43, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
   118     cmd[7] = (sizeof(buf))>>8;
   119     cmd[8] = (sizeof(buf))&0xFF;
   120     memset( buf, 0, sizeof(buf) );
   121     gdrom_error_t status = linux_send_command( fd, cmd, buf, &buflen, CGC_DATA_READ );
   122     if( status != 0 ) {
   123 	return status;
   124     }
   126     int max_track = 0;
   127     int last_track = -1;
   128     int leadout = -1;
   129     int len = (buf[0] << 8) | buf[1];
   130     int session_type = GDROM_MODE1;
   131     int i;
   132     for( i = 4; i<len; i+=11 ) {
   133 	int session = buf[i];
   134 	int adr = buf[i+1] >> 4;
   135 	int point = buf[i+3];
   136 	if( adr == 0x01 && point > 0 && point < 100 ) {
   137 	    /* Track info */
   138 	    int trackno = point-1;
   139 	    if( point > max_track ) {
   140 		max_track = point;
   141 	    }
   142 	    disc->track[trackno].flags = (buf[i+1] & 0x0F) << 4;
   143 	    disc->track[trackno].session = session - 1;
   144 	    disc->track[trackno].lba = MSFTOLBA(buf[i+8],buf[i+9],buf[i+10]);
   145 	    if( disc->track[trackno].flags & TRACK_DATA ) {
   146 		disc->track[trackno].mode = GDROM_MODE1;
   147 	    } else {
   148 		disc->track[trackno].mode = GDROM_CDDA;
   149 	    }
   150 	    if( last_track != -1 ) {
   151 		disc->track[last_track].sector_count = disc->track[trackno].lba -
   152 		    disc->track[last_track].lba;
   153 	    }
   154 	    last_track = trackno;
   155 	} else switch( (adr << 8) | point ) {
   156 	case 0x1A0: /* session info */
   157 	    if( buf[i+9] == 0x20 ) {
   158 		session_type = GDROM_MODE2;
   159 	    } else {
   160 		session_type = GDROM_MODE1;
   161 	    }
   162 	case 0x1A2: /* leadout */
   163 	    leadout = MSFTOLBA(buf[i+8], buf[i+9], buf[i+10]);
   164 	    break;
   165 	}
   166     }
   167     disc->track_count = max_track;
   169     if( leadout != -1 && last_track != -1 ) {
   170 	disc->track[last_track].sector_count = leadout - disc->track[last_track].lba;
   171     }
   172     return 0;
   173 }
   175 static gdrom_error_t linux_read_sector( gdrom_disc_t disc, uint32_t sector,
   176 					int mode, char *buf, uint32_t *length )
   177 {
   178     gdrom_image_t image = (gdrom_image_t)disc;
   179     int fd = fileno(image->file);
   180     uint32_t real_sector = sector - CD_MSF_OFFSET;
   181     uint32_t sector_size = MAX_SECTOR_SIZE;
   182     int i;
   183     char cmd[12] = { 0xBE, 0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
   185     cmd[1] = (mode & 0x0E) << 1;
   186     cmd[2] = (real_sector >> 24) & 0xFF;
   187     cmd[3] = (real_sector >> 16) & 0xFF;
   188     cmd[4] = (real_sector >> 8) & 0xFF;
   189     cmd[5] = real_sector & 0xFF;
   190     cmd[6] = 0;
   191     cmd[7] = 0;
   192     cmd[8] = 1;
   193     cmd[9] = 0x10;
   195     gdrom_error_t status = linux_send_command( fd, cmd, buf, &sector_size, CGC_DATA_READ );
   196     if( status != 0 ) {
   197 	return status;
   198     }
   199     *length = 2048;
   200     return 0;
   201 }
   203 /**
   204  * Send a packet command to the device and wait for a response. 
   205  * @return 0 on success, -1 on an operating system error, or a sense error
   206  * code on a device error.
   207  */
   208 static gdrom_error_t linux_send_command( int fd, char *cmd, char *buffer, size_t *buflen,
   209 					 int direction )
   210 {
   211     struct request_sense sense;
   212     struct cdrom_generic_command cgc;
   214     memset( &cgc, 0, sizeof(cgc) );
   215     memset( &sense, 0, sizeof(sense) );
   216     memcpy( cgc.cmd, cmd, 12 );
   217     cgc.buffer = buffer;
   218     cgc.buflen = *buflen;
   219     cgc.sense = &sense;
   220     cgc.data_direction = direction;
   222     if( ioctl(fd, CDROM_SEND_PACKET, &cgc) == -1 ) {
   223 	if( sense.sense_key == 0 ) {
   224 	    return -1; 
   225 	} else {
   226 	    /* TODO: Map newer codes back to the ones used by the gd-rom. */
   227 	    return sense.sense_key | (sense.asc<<8);
   228 	}
   229     } else {
   230 	*buflen = cgc.buflen;
   231 	return 0;
   232     }
   233 }
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