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      1 /*	$NetBSD: datafs.c,v 1.2 2008/04/28 20:23:18 martin Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2004 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by UCHIYAMA Yasushi.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <lib/libsa/stand.h>
     33 #include <lib/libkern/libkern.h>
     34 
     35 #include "local.h"
     36 
     37 FS_DEF(data);
     38 
     39 struct fs_ops datafs_ops = {
     40 	data_open, data_close, data_read, data_write, data_seek, data_stat
     41 };
     42 
     43 struct datafs {
     44 	uint8_t *ptr;
     45 	uint8_t *end;
     46 	uint8_t *start;
     47 	size_t size;
     48 } __data;
     49 
     50 void
     51 data_attach(void *addr, size_t size)
     52 {
     53 
     54 	__data.start = addr;
     55 	__data.size = size;
     56 }
     57 
     58 int
     59 data_open(const char *name, struct open_file *f)
     60 {
     61 
     62 	if (__data.size == 0) {
     63 		printf("no data\n");
     64 		return -1;
     65 	}
     66 
     67 	__data.ptr = __data.start;
     68 	__data.end = __data.ptr + __data.size;
     69 
     70 	return 0;
     71 }
     72 
     73 int
     74 data_close(struct open_file *f)
     75 {
     76 
     77 	return 0;
     78 }
     79 
     80 int
     81 data_read(struct open_file *f, void *buf, size_t size, size_t *resid)
     82 {
     83 	uint8_t *b = buf;
     84 	size_t sz;
     85 
     86 	twiddle();
     87 	if (__data.ptr + size < __data.end) {
     88 		sz = size;
     89 		memcpy(b, __data.ptr, sz);
     90 		__data.ptr += sz;
     91 	} else {
     92 		sz = (size_t)(__data.end - __data.ptr);
     93 		while (__data.ptr < __data.end)
     94 			*b++ = *__data.ptr++;
     95 	}
     96 
     97 	if (resid)
     98 		*resid = size - sz;
     99 
    100 	return 0;
    101 }
    102 
    103 int
    104 data_write(struct open_file *f, void *start, size_t size, size_t *resid)
    105 {
    106 
    107 	return 0;
    108 }
    109 
    110 off_t
    111 data_seek(struct open_file *f, off_t offset, int where)
    112 {
    113 	uint8_t *p = 0;
    114 
    115 	switch (where) {
    116 	case SEEK_SET:
    117 		p = __data.start + offset;
    118 		break;
    119 	case SEEK_CUR:
    120 		p = __data.ptr + offset;
    121 		break;
    122 	case SEEK_END:
    123 		p = __data.end + offset;
    124 		break;
    125 	default:
    126 		return EINVAL;
    127 	}
    128 
    129 	if (p < __data.start || p >= __data.end) {
    130 		return EINVAL;
    131 	}
    132 
    133 	__data.ptr = p;
    134 
    135 	return (off_t)(p - __data.start);
    136 }
    137 
    138 int
    139 data_stat(struct open_file *f, struct stat *stat)
    140 {
    141 
    142 	stat->st_size = __data.size;
    143 
    144 	return 0;
    145 }
    146