140 lines
4.1 KiB
C
140 lines
4.1 KiB
C
/*
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* media.h -
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*
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* Written by Eryk Vershen
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*/
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/*
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* Copyright 1997,1998 by Apple Computer, Inc.
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* All Rights Reserved
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*
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* Permission to use, copy, modify, and distribute this software and
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* its documentation for any purpose and without fee is hereby granted,
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* provided that the above copyright notice appears in all copies and
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* that both the copyright notice and this permission notice appear in
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* supporting documentation.
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*
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* APPLE COMPUTER DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
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* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE.
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*
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* IN NO EVENT SHALL APPLE COMPUTER BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
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* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
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* LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
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* NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
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* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#ifndef __media__
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#define __media__
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/*
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* Media is an abstraction of a disk device.
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*
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* A media object has the following visible attributes:
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*
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* a granularity (e.g. 512, 1024, 1, etc.)
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* a total size in bytes
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*
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* And the following operations are available:
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*
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* open
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* read @ byte offset for size in bytes
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* write @ byte offset for size in bytes
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* close
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*
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* XXX Should really split public media interface from "protected" interface.
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*/
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/*
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* Defines
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*/
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/*
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* Types
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*/
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/* those whose use media objects need just the pointer type */
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typedef struct media *MEDIA;
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/* those who define media objects need the struct and internal routine types */
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typedef long (*media_read)(MEDIA m, long long offset, unsigned long count, void *address);
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typedef long (*media_write)(MEDIA m, long long offset, unsigned long count, void *address);
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typedef long (*media_close)(MEDIA m);
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typedef long (*media_os_reload)(MEDIA m);
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struct media {
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long kind; /* kind of media - SCSI, IDE, etc. */
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unsigned long grain; /* granularity (offset & size) */
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long long size_in_bytes; /* offset granularity */
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media_read do_read; /* device specific routines */
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media_write do_write;
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media_close do_close;
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media_os_reload do_os_reload;
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/* specific media kinds will add extra info */
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};
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/* those whose use media object iterators need just the pointer type */
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typedef struct media_iterator *MEDIA_ITERATOR;
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/* those who define media object iterators need the struct and internal routine types */
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typedef void (*media_iterator_reset)(MEDIA_ITERATOR m);
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typedef char* (*media_iterator_step)(MEDIA_ITERATOR m);
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typedef void (*media_iterator_delete)(MEDIA_ITERATOR m);
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typedef enum {
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kInit,
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kReset,
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kIterating,
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kEnd
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} media_iterator_state;
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struct media_iterator {
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long kind; /* kind of media - SCSI, IDE, etc. */
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media_iterator_state state; /* init, reset, iterating, at_end */
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media_iterator_reset do_reset; /* device specific routines */
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media_iterator_step do_step;
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media_iterator_delete do_delete;
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/* specific media kinds will add extra info */
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};
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/*
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* Global Constants
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*/
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/*
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* Global Variables
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*/
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/*
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* Forward declarations
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*/
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/* those whose use media objects need these routines */
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unsigned long media_granularity(MEDIA m);
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long long media_total_size(MEDIA m);
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long read_media(MEDIA m, long long offset, unsigned long count, void *address);
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long write_media(MEDIA m, long long offset, unsigned long count, void *address);
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void close_media(MEDIA m);
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void os_reload_media(MEDIA m);
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/* those who define media objects need these routines also */
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long allocate_media_kind(void);
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MEDIA new_media(long size);
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void delete_media(MEDIA m);
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/* those whose use media object iterators need these routines */
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void reset_media_iterator(MEDIA_ITERATOR m);
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char *step_media_iterator(MEDIA_ITERATOR m);
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void delete_media_iterator(MEDIA_ITERATOR m);
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/* those who define media object iterators need these routines also */
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MEDIA_ITERATOR new_media_iterator(long size);
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void private_delete_media_iterator(MEDIA_ITERATOR m);
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#endif /* __media__ */
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