| Line 31... |
Line 31... |
/*
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/*
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D O S _ O P E N
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D O S _ O P E N
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*/
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*/
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int dos_open(struct dosparam *params)
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int dos_open(struct dosparam *params)
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{
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{
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int error;
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int error, start_sector, partition;
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unsigned char buf[512];
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unsigned char buf[512];
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struct inode *inode = ¶ms->inode;
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struct inode *inode = ¶ms->inode;
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struct file *filp = ¶ms->filp;
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struct file *filp = ¶ms->filp;
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struct request *request = ¶ms->request;
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struct request *request = ¶ms->request;
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if( (error = ata_open(inode, filp)) )
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if( (error = ata_open(inode, filp)) )
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return error;
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return error;
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/* device opened, read boot-sector */
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/* device opened, read MBR */
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request->cmd = READ;
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request->cmd = READ;
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request->sector = 0;
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request->sector = 0;
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request->nr_sectors = 1;
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request->nr_sectors = 1;
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request->buffer = buf;
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request->buffer = buf;
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/* skip bootload (446) bytes */
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/* currently only support the first partition (partition 4) */
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/* This is OK, because CompactFLASH devices only have 1 partition */
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if ( (error = ata_request(inode, filp, request)) )
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return error;
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partition = 0; /* first partition */
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partition *= 16; /* 16 bytes per partition table */
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partition += 446; /* skip bootloader, go to partition table */
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start_sector = buf[partition +11] << 24 |
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buf[partition +10] << 16 |
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buf[partition +9] << 8 |
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buf[partition +8];
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/* device opened, read boot-sector */
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request->cmd = READ;
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request->sector = start_sector;
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request->nr_sectors = 1;
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request->buffer = buf;
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if ( (error = ata_request(inode, filp, request)) )
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if ( (error = ata_request(inode, filp, request)) )
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return error;
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return error;
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/* get the necessary data from the boot-sector */
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/* get the necessary data from the boot-sector */
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params->bytes_per_sector = (buf[12]<<8) | buf[11];
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params->bytes_per_sector = (buf[12]<<8) | buf[11];
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| Line 60... |
Line 80... |
params->root_entries = (buf[18]<<8) | buf[17];
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params->root_entries = (buf[18]<<8) | buf[17];
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params->sectors_per_cluster = buf[13];
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params->sectors_per_cluster = buf[13];
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/* set start of current directory to start of root-directory */
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/* set start of current directory to start of root-directory */
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params->ssector = params->fats * params->sectors_per_fat +1;
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params->ssector = start_sector + params->fats * params->sectors_per_fat +1;
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/* set current sector to start of root-directory */
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/* set current sector to start of root-directory */
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params->csector = params->ssector;
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params->csector = params->ssector;
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/* set start-entry number */
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/* set start-entry number */
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