com32/lib/sys/file.h

   1 /* ----------------------------------------------------------------------- *
   2  *
   3  *   Copyright 2003-2008 H. Peter Anvin - All Rights Reserved
   4  *
   5  *   Permission is hereby granted, free of charge, to any person
   6  *   obtaining a copy of this software and associated documentation
   7  *   files (the "Software"), to deal in the Software without
   8  *   restriction, including without limitation the rights to use,
   9  *   copy, modify, merge, publish, distribute, sublicense, and/or
  10  *   sell copies of the Software, and to permit persons to whom
  11  *   the Software is furnished to do so, subject to the following
  12  *   conditions:
  13  *
  14  *   The above copyright notice and this permission notice shall
  15  *   be included in all copies or substantial portions of the Software.
  16  *
  17  *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  18  *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
  19  *   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  20  *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  21  *   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  22  *   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  23  *   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  24  *   OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  * ----------------------------------------------------------------------- */
  27
  28 /*
  29  * file.h
  30  *
  31  * Internal implementation of file I/O for COM32
  32  */
  33
  34 #ifndef _COM32_SYS_FILE_H
  35 #define _COM32_SYS_FILE_H
  36
  37 #include <inttypes.h>
  38 #include <stdlib.h>
  39 #include <sys/types.h>
  40 #include <dev.h>
  41 #include <fcntl.h>
  42 #include <syslinux/pmapi.h>
  43
  44 /* Device structure; contains the relevant operations */
  45
  46 struct file_info;
  47
  48 #define __DEV_MAGIC     0xf4e7
  49 #define __DEV_TTY       0x0001  /* TTY - must be bit 0 */
  50 #define __DEV_FILE      0x0002  /* Ordinary file */
  51 #define __DEV_OUTPUT    0x0004  /* This is an output device */
  52 #define __DEV_INPUT     0       /* Dummy */
  53 #define __DEV_ERROR     0x0008  /* This is the error device */
  54 #define __DEV_NULL      0x0010  /* This is the null device */
  55
  56 struct input_dev {
  57     uint16_t dev_magic;         /* Magic number */
  58     uint16_t flags;             /* Flags */
  59     int fileflags;              /* Permitted file flags */
  60     ssize_t (*read)(struct file_info *, void *, size_t);
  61     int (*close)(struct file_info *);
  62     int (*open)(struct file_info *);
  63 };
  64
  65 struct output_dev {
  66     uint16_t dev_magic;         /* Magic number */
  67     uint16_t flags;             /* Flags */
  68     int fileflags;
  69     ssize_t (*write)(struct file_info *, const void *, size_t);
  70     int (*close)(struct file_info *);
  71     int (*open)(struct file_info *);
  72     const struct output_dev *fallback;  /* Fallback option for certain consoles */
  73 };
  74
  75 /* File structure */
  76
  77 #define NFILES 128              /* Number of files to support */
  78 #define MAXBLOCK 16384          /* Defined by ABI */
  79
  80 struct file_info {
  81     const struct input_dev *iop;        /* Input operations */
  82     const struct output_dev *oop;       /* Output operations */
  83
  84     /* Output file data */
  85     struct {
  86         int rows, cols;         /* Rows and columns */
  87     } o;
  88
  89     /* Structure used for input blocking */
  90     struct {
  91         struct com32_filedata fd;
  92         size_t offset;          /* Current file offset */
  93         size_t nbytes;          /* Number of bytes available in buffer */
  94         char *datap;            /* Current data pointer */
  95         void *pvt;              /* Private pointer for driver */
  96         char buf[MAXBLOCK];
  97     } i;
  98 };
  99
 100 extern struct file_info __file_info[NFILES];
 101 extern const struct input_dev __file_dev;
 102
 103 /* Line input discipline */
 104 ssize_t __line_input(struct file_info *fp, char *buf, size_t bufsize,
 105                      ssize_t(*get_char) (struct file_info *, void *, size_t));
 106
 107 #endif /* _COM32_SYS_FILE_H */