mirror of
https://github.com/xcat2/xNBA.git
synced 2024-12-23 19:51:46 +00:00
Refactored to reduce code size; now down from 1304 to 1105 bytes.
Tidied up debug messages; the log now contains one line per INT 13 operation, looking like INT 13,08 (80): Get drive parameters INT 13,02 (80): Read: C/H/S 0/47/14 = LBA 0xb9e <-> 1084:0000 (count 106)
This commit is contained in:
Michael Brown
parent
af4aacb978
commit
ca2519cea3
@ -64,89 +64,6 @@ extern void int13_exec_fail ( void );
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/** List of registered emulated drives */
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static LIST_HEAD ( drives );
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/**
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* Convert CHS address to linear address
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*
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* @v drive Emulated drive
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* @v ch Low bits of cylinder number
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* @v cl (bits 7:6) High bits of cylinder number
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* @v cl (bits 5:0) Sector number
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* @v dh Head number
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* @ret lba LBA address
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*
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*/
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static unsigned long chs_to_lba ( struct int13_drive *drive,
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struct i386_all_regs *ix86 ) {
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unsigned int cylinder;
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unsigned int head;
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unsigned int sector;
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unsigned long lba;
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cylinder = ( ( ( ix86->regs.cl & 0xc0 ) << 8 ) | ix86->regs.ch );
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head = ix86->regs.dh;
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sector = ( ix86->regs.cl & 0x3f );
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assert ( cylinder < drive->cylinders );
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assert ( head < drive->heads );
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assert ( ( sector >= 1 ) && ( sector <= drive->sectors_per_track ) );
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lba = ( ( ( ( cylinder * drive->heads ) + head )
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* drive->sectors_per_track ) + sector - 1 );
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DBG ( "C/H/S address %x/%x/%x -> LBA %lx\n",
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cylinder, head, sector, lba );
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return lba;
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}
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/**
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* Read from drive to real-mode data buffer
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*
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* @v drive Emulated drive
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* @v lba LBA starting sector number
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* @v data Data buffer
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* @v count Number of sectors to read
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* @ret status Status code
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*/
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static int int13_read ( struct int13_drive *drive, uint64_t lba,
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struct segoff data, unsigned long count ) {
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struct block_device *blockdev = drive->blockdev;
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userptr_t buffer = real_to_user ( data.segment, data.offset );
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int rc;
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DBG ( "Read %lx sectors from %llx to %04x:%04x\n", count,
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( unsigned long long ) lba, data.segment, data.offset );
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if ( ( rc = blockdev->read ( blockdev, lba, count, buffer ) ) != 0 )
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return INT13_STATUS_READ_ERROR;
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return 0;
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}
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/**
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* Write from real-mode data buffer to drive
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*
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* @v drive Emulated drive
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* @v lba LBA starting sector number
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* @v data Data buffer
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* @v count Number of sectors to read
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* @ret status Status code
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*/
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static int int13_write ( struct int13_drive *drive, uint64_t lba,
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struct segoff data, unsigned long count ) {
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struct block_device *blockdev = drive->blockdev;
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userptr_t buffer = real_to_user ( data.segment, data.offset );
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int rc;
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DBG ( "Write %lx sectors from %04x:%04x to %llx\n", count,
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data.segment, data.offset, ( unsigned long long ) lba );
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if ( ( rc = blockdev->write ( blockdev, lba, count, buffer ) ) != 0 )
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return INT13_STATUS_WRITE_ERROR;
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return 0;
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}
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/**
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* INT 13, 00 - Reset disk system
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*
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@ -171,6 +88,61 @@ static int int13_get_last_status ( struct int13_drive *drive,
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return drive->last_status;
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}
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/**
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* Read / write sectors
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*
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* @v drive Emulated drive
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* @v al Number of sectors to read or write (must be nonzero)
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* @v ch Low bits of cylinder number
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* @v cl (bits 7:6) High bits of cylinder number
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* @v cl (bits 5:0) Sector number
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* @v dh Head number
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* @v es:bx Data buffer
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* @v io Read / write method
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* @ret status Status code
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* @ret al Number of sectors read or written
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*/
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static int int13_rw_sectors ( struct int13_drive *drive,
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struct i386_all_regs *ix86,
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int ( * io ) ( struct block_device *blockdev,
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uint64_t block,
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unsigned long count,
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userptr_t buffer ) ) {
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struct block_device *blockdev = drive->blockdev;
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unsigned int cylinder, head, sector;
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unsigned long lba;
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unsigned int count;
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userptr_t buffer;
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/* Calculate parameters */
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cylinder = ( ( ( ix86->regs.cl & 0xc0 ) << 8 ) | ix86->regs.ch );
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assert ( cylinder < drive->cylinders );
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head = ix86->regs.dh;
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assert ( head < drive->heads );
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sector = ( ix86->regs.cl & 0x3f );
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assert ( ( sector >= 1 ) && ( sector <= drive->sectors_per_track ) );
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lba = ( ( ( ( cylinder * drive->heads ) + head )
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* drive->sectors_per_track ) + sector - 1 );
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count = ix86->regs.al;
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buffer = real_to_user ( ix86->segs.es, ix86->regs.bx );
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DBG ( "C/H/S %d/%d/%d = LBA %#lx <-> %04x:%04x (count %d)\n", cylinder,
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head, sector, lba, ix86->segs.es, ix86->regs.bx, count );
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/* Validate blocksize */
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if ( blockdev->blksize != INT13_BLKSIZE ) {
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DBG ( "Invalid blocksize (%zd) for non-extended read/write\n",
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blockdev->blksize );
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return INT13_STATUS_INVALID;
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}
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/* Read from / write to block device */
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if ( io ( blockdev, lba, count, buffer ) != 0 )
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return INT13_STATUS_READ_ERROR;
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return 0;
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}
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/**
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* INT 13, 02 - Read sectors
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*
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@ -186,20 +158,8 @@ static int int13_get_last_status ( struct int13_drive *drive,
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*/
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static int int13_read_sectors ( struct int13_drive *drive,
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struct i386_all_regs *ix86 ) {
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unsigned long lba = chs_to_lba ( drive, ix86 );
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unsigned int count = ix86->regs.al;
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struct segoff data = {
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.segment = ix86->segs.es,
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.offset = ix86->regs.bx,
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};
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if ( drive->blockdev->blksize != INT13_BLKSIZE ) {
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DBG ( "Invalid blocksize (%zd) for non-extended read\n",
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drive->blockdev->blksize );
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return INT13_STATUS_INVALID;
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}
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return int13_read ( drive, lba, data, count );
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DBG ( "Read: " );
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return int13_rw_sectors ( drive, ix86, drive->blockdev->read );
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}
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/**
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@ -217,20 +177,8 @@ static int int13_read_sectors ( struct int13_drive *drive,
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*/
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static int int13_write_sectors ( struct int13_drive *drive,
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struct i386_all_regs *ix86 ) {
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unsigned long lba = chs_to_lba ( drive, ix86 );
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unsigned int count = ix86->regs.al;
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struct segoff data = {
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.segment = ix86->segs.es,
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.offset = ix86->regs.bx,
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};
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if ( drive->blockdev->blksize != INT13_BLKSIZE ) {
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DBG ( "Invalid blocksize (%zd) for non-extended write\n",
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drive->blockdev->blksize );
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return INT13_STATUS_INVALID;
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}
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return int13_write ( drive, lba, data, count );
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DBG ( "Write: " );
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return int13_rw_sectors ( drive, ix86, drive->blockdev->write );
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}
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/**
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@ -280,6 +228,42 @@ static int int13_extension_check ( struct int13_drive *drive __unused,
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}
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}
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/**
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* Extended read / write
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*
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* @v drive Emulated drive
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* @v ds:si Disk address packet
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* @v io Read / write method
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* @ret status Status code
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*/
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static int int13_extended_rw ( struct int13_drive *drive,
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struct i386_all_regs *ix86,
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int ( * io ) ( struct block_device *blockdev,
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uint64_t block,
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unsigned long count,
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userptr_t buffer ) ) {
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struct block_device *blockdev = drive->blockdev;
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struct int13_disk_address addr;
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uint64_t lba;
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unsigned long count;
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userptr_t buffer;
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/* Read parameters from disk address structure */
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copy_from_real ( &addr, ix86->segs.ds, ix86->regs.si, sizeof ( addr ));
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lba = addr.lba;
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count = addr.count;
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buffer = real_to_user ( addr.buffer.segment, addr.buffer.offset );
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DBG ( "LBA %#llx <-> %04x:%04x (count %ld)\n", (unsigned long long)lba,
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addr.buffer.segment, addr.buffer.offset, count );
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/* Read from / write to block device */
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if ( io ( blockdev, lba, count, buffer ) != 0 )
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return INT13_STATUS_READ_ERROR;
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return 0;
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}
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/**
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* INT 13, 42 - Extended read
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*
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@ -289,11 +273,8 @@ static int int13_extension_check ( struct int13_drive *drive __unused,
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*/
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static int int13_extended_read ( struct int13_drive *drive,
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struct i386_all_regs *ix86 ) {
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struct int13_disk_address addr;
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copy_from_real ( &addr, ix86->segs.ds, ix86->regs.si,
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sizeof ( addr ) );
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return int13_read ( drive, addr.lba, addr.buffer, addr.count );
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DBG ( "Extended read: " );
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return int13_extended_rw ( drive, ix86, drive->blockdev->read );
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}
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/**
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@ -305,11 +286,8 @@ static int int13_extended_read ( struct int13_drive *drive,
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*/
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static int int13_extended_write ( struct int13_drive *drive,
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struct i386_all_regs *ix86 ) {
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struct int13_disk_address addr;
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copy_from_real ( &addr, ix86->segs.ds, ix86->regs.si,
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sizeof ( addr ) );
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return int13_write ( drive, addr.lba, addr.buffer, addr.count );
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DBG ( "Extended write: " );
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return int13_extended_rw ( drive, ix86, drive->blockdev->write );
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}
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/**
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@ -351,7 +329,7 @@ static void int13 ( struct i386_all_regs *ix86 ) {
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if ( drive->drive != ix86->regs.dl )
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continue;
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DBG ( "INT 13, %02x on drive %02x\n", ix86->regs.ah,
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DBG ( "INT 13,%02x (%02x): ", ix86->regs.ah,
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ix86->regs.dl );
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switch ( ix86->regs.ah ) {
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