diff options
| -rw-r--r-- | src/arch/i386/interface/pcbios/int13.c | 218 |
1 files changed, 98 insertions, 120 deletions
diff --git a/src/arch/i386/interface/pcbios/int13.c b/src/arch/i386/interface/pcbios/int13.c index d87428f7f..8df4c7973 100644 --- a/src/arch/i386/interface/pcbios/int13.c +++ b/src/arch/i386/interface/pcbios/int13.c @@ -65,113 +65,85 @@ extern void int13_exec_fail ( void ); static LIST_HEAD ( drives ); /** - * Convert CHS address to linear address + * INT 13, 00 - Reset disk system * * @v drive Emulated drive - * @v ch Low bits of cylinder number - * @v cl (bits 7:6) High bits of cylinder number - * @v cl (bits 5:0) Sector number - * @v dh Head number - * @ret lba LBA address - * + * @ret status Status code */ -static unsigned long chs_to_lba ( struct int13_drive *drive, - struct i386_all_regs *ix86 ) { - unsigned int cylinder; - unsigned int head; - unsigned int sector; - unsigned long lba; - - cylinder = ( ( ( ix86->regs.cl & 0xc0 ) << 8 ) | ix86->regs.ch ); - head = ix86->regs.dh; - sector = ( ix86->regs.cl & 0x3f ); - - assert ( cylinder < drive->cylinders ); - assert ( head < drive->heads ); - assert ( ( sector >= 1 ) && ( sector <= drive->sectors_per_track ) ); - - lba = ( ( ( ( cylinder * drive->heads ) + head ) - * drive->sectors_per_track ) + sector - 1 ); - - DBG ( "C/H/S address %x/%x/%x -> LBA %lx\n", - cylinder, head, sector, lba ); - - return lba; +static int int13_reset ( struct int13_drive *drive __unused, + struct i386_all_regs *ix86 __unused ) { + DBG ( "Reset drive\n" ); + return 0; } /** - * Read from drive to real-mode data buffer + * INT 13, 01 - Get status of last operation * * @v drive Emulated drive - * @v lba LBA starting sector number - * @v data Data buffer - * @v count Number of sectors to read * @ret status Status code */ -static int int13_read ( struct int13_drive *drive, uint64_t lba, - struct segoff data, unsigned long count ) { - struct block_device *blockdev = drive->blockdev; - userptr_t buffer = real_to_user ( data.segment, data.offset ); - int rc; - - DBG ( "Read %lx sectors from %llx to %04x:%04x\n", count, - ( unsigned long long ) lba, data.segment, data.offset ); - - if ( ( rc = blockdev->read ( blockdev, lba, count, buffer ) ) != 0 ) - return INT13_STATUS_READ_ERROR; - - return 0; +static int int13_get_last_status ( struct int13_drive *drive, + struct i386_all_regs *ix86 __unused ) { + DBG ( "Get status of last operation\n" ); + return drive->last_status; } /** - * Write from real-mode data buffer to drive + * Read / write sectors * * @v drive Emulated drive - * @v lba LBA starting sector number - * @v data Data buffer - * @v count Number of sectors to read + * @v al Number of sectors to read or write (must be nonzero) + * @v ch Low bits of cylinder number + * @v cl (bits 7:6) High bits of cylinder number + * @v cl (bits 5:0) Sector number + * @v dh Head number + * @v es:bx Data buffer + * @v io Read / write method * @ret status Status code + * @ret al Number of sectors read or written */ -static int int13_write ( struct int13_drive *drive, uint64_t lba, - struct segoff data, unsigned long count ) { +static int int13_rw_sectors ( struct int13_drive *drive, + struct i386_all_regs *ix86, + int ( * io ) ( struct block_device *blockdev, + uint64_t block, + unsigned long count, + userptr_t buffer ) ) { struct block_device *blockdev = drive->blockdev; - userptr_t buffer = real_to_user ( data.segment, data.offset ); - int rc; + unsigned int cylinder, head, sector; + unsigned long lba; + unsigned int count; + userptr_t buffer; - DBG ( "Write %lx sectors from %04x:%04x to %llx\n", count, - data.segment, data.offset, ( unsigned long long ) lba ); + /* Calculate parameters */ + cylinder = ( ( ( ix86->regs.cl & 0xc0 ) << 8 ) | ix86->regs.ch ); + assert ( cylinder < drive->cylinders ); + head = ix86->regs.dh; + assert ( head < drive->heads ); + sector = ( ix86->regs.cl & 0x3f ); + assert ( ( sector >= 1 ) && ( sector <= drive->sectors_per_track ) ); + lba = ( ( ( ( cylinder * drive->heads ) + head ) + * drive->sectors_per_track ) + sector - 1 ); + count = ix86->regs.al; + buffer = real_to_user ( ix86->segs.es, ix86->regs.bx ); - if ( ( rc = blockdev->write ( blockdev, lba, count, buffer ) ) != 0 ) - return INT13_STATUS_WRITE_ERROR; + DBG ( "C/H/S %d/%d/%d = LBA %#lx <-> %04x:%04x (count %d)\n", cylinder, + head, sector, lba, ix86->segs.es, ix86->regs.bx, count ); - return 0; -} + /* Validate blocksize */ + if ( blockdev->blksize != INT13_BLKSIZE ) { + DBG ( "Invalid blocksize (%zd) for non-extended read/write\n", + blockdev->blksize ); + return INT13_STATUS_INVALID; + } + + /* Read from / write to block device */ + if ( io ( blockdev, lba, count, buffer ) != 0 ) + return INT13_STATUS_READ_ERROR; -/** - * INT 13, 00 - Reset disk system - * - * @v drive Emulated drive - * @ret status Status code - */ -static int int13_reset ( struct int13_drive *drive __unused, - struct i386_all_regs *ix86 __unused ) { - DBG ( "Reset drive\n" ); return 0; } /** - * INT 13, 01 - Get status of last operation - * - * @v drive Emulated drive - * @ret status Status code - */ -static int int13_get_last_status ( struct int13_drive *drive, - struct i386_all_regs *ix86 __unused ) { - DBG ( "Get status of last operation\n" ); - return drive->last_status; -} - -/** * INT 13, 02 - Read sectors * * @v drive Emulated drive @@ -186,20 +158,8 @@ static int int13_get_last_status ( struct int13_drive *drive, */ static int int13_read_sectors ( struct int13_drive *drive, struct i386_all_regs *ix86 ) { - unsigned long lba = chs_to_lba ( drive, ix86 ); - unsigned int count = ix86->regs.al; - struct segoff data = { - .segment = ix86->segs.es, - .offset = ix86->regs.bx, - }; - - if ( drive->blockdev->blksize != INT13_BLKSIZE ) { - DBG ( "Invalid blocksize (%zd) for non-extended read\n", - drive->blockdev->blksize ); - return INT13_STATUS_INVALID; - } - - return int13_read ( drive, lba, data, count ); + DBG ( "Read: " ); + return int13_rw_sectors ( drive, ix86, drive->blockdev->read ); } /** @@ -217,20 +177,8 @@ static int int13_read_sectors ( struct int13_drive *drive, */ static int int13_write_sectors ( struct int13_drive *drive, struct i386_all_regs *ix86 ) { - unsigned long lba = chs_to_lba ( drive, ix86 ); - unsigned int count = ix86->regs.al; - struct segoff data = { - .segment = ix86->segs.es, - .offset = ix86->regs.bx, - }; - - if ( drive->blockdev->blksize != INT13_BLKSIZE ) { - DBG ( "Invalid blocksize (%zd) for non-extended write\n", - drive->blockdev->blksize ); - return INT13_STATUS_INVALID; - } - - return int13_write ( drive, lba, data, count ); + DBG ( "Write: " ); + return int13_rw_sectors ( drive, ix86, drive->blockdev->write ); } /** @@ -281,6 +229,42 @@ static int int13_extension_check ( struct int13_drive *drive __unused, } /** + * Extended read / write + * + * @v drive Emulated drive + * @v ds:si Disk address packet + * @v io Read / write method + * @ret status Status code + */ +static int int13_extended_rw ( struct int13_drive *drive, + struct i386_all_regs *ix86, + int ( * io ) ( struct block_device *blockdev, + uint64_t block, + unsigned long count, + userptr_t buffer ) ) { + struct block_device *blockdev = drive->blockdev; + struct int13_disk_address addr; + uint64_t lba; + unsigned long count; + userptr_t buffer; + + /* Read parameters from disk address structure */ + copy_from_real ( &addr, ix86->segs.ds, ix86->regs.si, sizeof ( addr )); + lba = addr.lba; + count = addr.count; + buffer = real_to_user ( addr.buffer.segment, addr.buffer.offset ); + + DBG ( "LBA %#llx <-> %04x:%04x (count %ld)\n", (unsigned long long)lba, + addr.buffer.segment, addr.buffer.offset, count ); + + /* Read from / write to block device */ + if ( io ( blockdev, lba, count, buffer ) != 0 ) + return INT13_STATUS_READ_ERROR; + + return 0; +} + +/** * INT 13, 42 - Extended read * * @v drive Emulated drive @@ -289,11 +273,8 @@ static int int13_extension_check ( struct int13_drive *drive __unused, */ static int int13_extended_read ( struct int13_drive *drive, struct i386_all_regs *ix86 ) { - struct int13_disk_address addr; - - copy_from_real ( &addr, ix86->segs.ds, ix86->regs.si, - sizeof ( addr ) ); - return int13_read ( drive, addr.lba, addr.buffer, addr.count ); + DBG ( "Extended read: " ); + return int13_extended_rw ( drive, ix86, drive->blockdev->read ); } /** @@ -305,11 +286,8 @@ static int int13_extended_read ( struct int13_drive *drive, */ static int int13_extended_write ( struct int13_drive *drive, struct i386_all_regs *ix86 ) { - struct int13_disk_address addr; - - copy_from_real ( &addr, ix86->segs.ds, ix86->regs.si, - sizeof ( addr ) ); - return int13_write ( drive, addr.lba, addr.buffer, addr.count ); + DBG ( "Extended write: " ); + return int13_extended_rw ( drive, ix86, drive->blockdev->write ); } /** @@ -351,7 +329,7 @@ static void int13 ( struct i386_all_regs *ix86 ) { if ( drive->drive != ix86->regs.dl ) continue; - DBG ( "INT 13, %02x on drive %02x\n", ix86->regs.ah, + DBG ( "INT 13,%02x (%02x): ", ix86->regs.ah, ix86->regs.dl ); switch ( ix86->regs.ah ) { |