#ifndef INT13_H #define INT13_H /** @file * * INT 13 emulation * */ FILE_LICENCE ( GPL2_OR_LATER ); #include #include #include struct block_device; /** * @defgroup int13ops INT 13 operation codes * @{ */ /** Reset disk system */ #define INT13_RESET 0x00 /** Get status of last operation */ #define INT13_GET_LAST_STATUS 0x01 /** Read sectors */ #define INT13_READ_SECTORS 0x02 /** Write sectors */ #define INT13_WRITE_SECTORS 0x03 /** Get drive parameters */ #define INT13_GET_PARAMETERS 0x08 /** Get disk type */ #define INT13_GET_DISK_TYPE 0x15 /** Extensions installation check */ #define INT13_EXTENSION_CHECK 0x41 /** Extended read */ #define INT13_EXTENDED_READ 0x42 /** Extended write */ #define INT13_EXTENDED_WRITE 0x43 /** Get extended drive parameters */ #define INT13_GET_EXTENDED_PARAMETERS 0x48 /** Get CD-ROM status / terminate emulation */ #define INT13_CDROM_STATUS_TERMINATE 0x4b /** @} */ /** * @defgroup int13status INT 13 status codes * @{ */ /** Operation completed successfully */ #define INT13_STATUS_SUCCESS 0x00 /** Invalid function or parameter */ #define INT13_STATUS_INVALID 0x01 /** Read error */ #define INT13_STATUS_READ_ERROR 0x04 /** Write error */ #define INT13_STATUS_WRITE_ERROR 0xcc /** @} */ /** Block size for non-extended INT 13 calls */ #define INT13_BLKSIZE 512 /** An INT 13 emulated drive */ struct int13_drive { /** List of all registered drives */ struct list_head list; /** Underlying block device */ struct block_device *blockdev; /** BIOS in-use drive number (0x80-0xff) */ unsigned int drive; /** BIOS natural drive number (0x80-0xff) * * This is the drive number that would have been assigned by * 'naturally' appending the drive to the end of the BIOS * drive list. * * If the emulated drive replaces a preexisting drive, this is * the drive number that the preexisting drive gets remapped * to. */ unsigned int natural_drive; /** Number of cylinders * * The cylinder number field in an INT 13 call is ten bits * wide, giving a maximum of 1024 cylinders. Conventionally, * when the 7.8GB limit of a CHS address is exceeded, it is * the number of cylinders that is increased beyond the * addressable limit. */ unsigned int cylinders; /** Number of heads * * The head number field in an INT 13 call is eight bits wide, * giving a maximum of 256 heads. However, apparently all * versions of MS-DOS up to and including Win95 fail with 256 * heads, so the maximum encountered in practice is 255. */ unsigned int heads; /** Number of sectors per track * * The sector number field in an INT 13 call is six bits wide, * giving a maximum of 63 sectors, since sector numbering * (unlike head and cylinder numbering) starts at 1, not 0. */ unsigned int sectors_per_track; /** Status of last operation */ int last_status; }; /** An INT 13 disk address packet */ struct int13_disk_address { /** Size of the packet, in bytes */ uint8_t bufsize; /** Reserved, must be zero */ uint8_t reserved; /** Block count */ uint16_t count; /** Data buffer */ struct segoff buffer; /** Starting block number */ uint64_t lba; /** Data buffer (EDD-3.0 only) */ uint64_t buffer_phys; } __attribute__ (( packed )); /** INT 13 disk parameters */ struct int13_disk_parameters { /** Size of this structure */ uint16_t bufsize; /** Flags */ uint16_t flags; /** Number of cylinders */ uint32_t cylinders; /** Number of heads */ uint32_t heads; /** Number of sectors per track */ uint32_t sectors_per_track; /** Total number of sectors on drive */ uint64_t sectors; /** Bytes per sector */ uint16_t sector_size; } __attribute__ (( packed )); /** * @defgroup int13types INT 13 disk types * @{ */ /** No such drive */ #define INT13_DISK_TYPE_NONE 0x00 /** Floppy without change-line support */ #define INT13_DISK_TYPE_FDD 0x01 /** Floppy with change-line support */ #define INT13_DISK_TYPE_FDD_CL 0x02 /** Hard disk */ #define INT13_DISK_TYPE_HDD 0x03 /** @} */ /** * @defgroup int13flags INT 13 disk parameter flags * @{ */ /** DMA boundary errors handled transparently */ #define INT13_FL_DMA_TRANSPARENT 0x01 /** CHS information is valid */ #define INT13_FL_CHS_VALID 0x02 /** Removable drive */ #define INT13_FL_REMOVABLE 0x04 /** Write with verify supported */ #define INT13_FL_VERIFIABLE 0x08 /** Has change-line supported (valid only for removable drives) */ #define INT13_FL_CHANGE_LINE 0x10 /** Drive can be locked (valid only for removable drives) */ #define INT13_FL_LOCKABLE 0x20 /** CHS is max possible, not current media (valid only for removable drives) */ #define INT13_FL_CHS_MAX 0x40 /** @} */ /** * @defgroup int13exts INT 13 extension flags * @{ */ /** Extended disk access functions supported */ #define INT13_EXTENSION_LINEAR 0x01 /** Removable drive functions supported */ #define INT13_EXTENSION_REMOVABLE 0x02 /** EDD functions supported */ #define INT13_EXTENSION_EDD 0x04 /** @} */ /** * @defgroup int13vers INT 13 extension versions * @{ */ /** INT13 extensions version 1.x */ #define INT13_EXTENSION_VER_1_X 0x01 /** INT13 extensions version 2.0 (EDD-1.0) */ #define INT13_EXTENSION_VER_2_0 0x20 /** INT13 extensions version 2.1 (EDD-1.1) */ #define INT13_EXTENSION_VER_2_1 0x21 /** INT13 extensions version 3.0 (EDD-3.0) */ #define INT13_EXTENSION_VER_3_0 0x30 /** @} */ /** Bootable CD-ROM specification packet */ struct int13_cdrom_specification { /** Size of packet in bytes */ uint8_t size; /** Boot media type */ uint8_t media_type; /** Drive number */ uint8_t drive; /** CD-ROM controller number */ uint8_t controller; /** LBA of disk image to emulate */ uint32_t lba; /** Device specification */ uint16_t device; /** Segment of 3K buffer for caching CD-ROM reads */ uint16_t cache_segment; /** Load segment for initial boot image */ uint16_t load_segment; /** Number of 512-byte sectors to load */ uint16_t load_sectors; /** Low 8 bits of cylinder number */ uint8_t cyl; /** Sector number, plus high 2 bits of cylinder number */ uint8_t cyl_sector; /** Head number */ uint8_t head; } __attribute__ (( packed )); /** A C/H/S address within a partition table entry */ struct partition_chs { /** Head number */ uint8_t head; /** Sector number, plus high 2 bits of cylinder number */ uint8_t cyl_sector; /** Low 8 bits of cylinder number */ uint8_t cyl; } __attribute__ (( packed )); #define PART_HEAD(chs) ( (chs).head ) #define PART_SECTOR(chs) ( (chs).cyl_sector & 0x3f ) #define PART_CYLINDER(chs) ( (chs).cyl | ( ( (chs).cyl_sector & 0xc0 ) << 2 ) ) /** A partition table entry within the MBR */ struct partition_table_entry { /** Bootable flag */ uint8_t bootable; /** C/H/S start address */ struct partition_chs chs_start; /** System indicator (partition type) */ uint8_t type; /** C/H/S end address */ struct partition_chs chs_end; /** Linear start address */ uint32_t start; /** Linear length */ uint32_t length; } __attribute__ (( packed )); /** A Master Boot Record */ struct master_boot_record { uint8_t pad[446]; /** Partition table */ struct partition_table_entry partitions[4]; /** 0x55aa MBR signature */ uint16_t signature; } __attribute__ (( packed )); extern void register_int13_drive ( struct int13_drive *drive ); extern void unregister_int13_drive ( struct int13_drive *drive ); extern int int13_boot ( unsigned int drive ); #endif /* INT13_H */