1/*
2Copyright (c) 2003 Hewlett-Packard Development Company, L.P.
3Permission is hereby granted, free of charge, to any person
4obtaining a copy of this software and associated documentation
5files (the "Software"), to deal in the Software without
6restriction, including without limitation the rights to use,
7copy, modify, merge, publish, distribute, sublicense, and/or sell
8copies of the Software, and to permit persons to whom the
9Software is furnished to do so, subject to the following
10conditions:
11
12The above copyright notice and this permission notice shall be
13included in all copies or substantial portions of the Software.
14
15THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
17OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
19HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
20WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22OTHER DEALINGS IN THE SOFTWARE.
23*/
24
25#include "uwx_env.h"
26#include "uwx_bstream.h"
27
28
29/* uwx_init_bstream: initialize a byte stream for reading */
30
31void uwx_init_bstream(
32 struct uwx_bstream *bstream,
33 struct uwx_env *env,
34 uint64_t source,
35 unsigned int len,
36 int request)
37{
38 bstream->buf = 0;
39 if (env->remote) {
40 bstream->source = source;
41 bstream->bufp = (unsigned char *) &bstream->buf;
42 bstream->nbuf = 0;
43 bstream->copyin = env->copyin;
44 bstream->cb_token = env->cb_token;
45 bstream->request = request;
46 }
47 else {
48 bstream->source = 0;
49 bstream->bufp = (unsigned char *) source;
50 bstream->nbuf = len;
51 bstream->copyin = 0;
52 bstream->cb_token = 0;
53 bstream->request = 0;
54 }
55 bstream->ntotal = len;
56 bstream->peekc = -1;
57}
58
59
60/* uwx_get_byte: read the next byte from the byte stream */
61
62int uwx_get_byte(struct uwx_bstream *bstream)
63{
64 int len;
65 int n;
66 int b;
67
68 if (bstream->peekc >= 0) {
69 b = bstream->peekc;
70 bstream->peekc = -1;
71 return b;
72 }
73 if (bstream->ntotal <= 0)
74 return -1;
75 if (bstream->nbuf <= 0) {
76 if (bstream->source & 0x7 || bstream->ntotal < sizeof(uint64_t))
77 len = sizeof(uint32_t);
78 else
79 len = sizeof(uint64_t);
80 n = (*bstream->copyin)(bstream->request, (char *)&bstream->buf,
81 bstream->source, len, bstream->cb_token);
82 if (n != len)
83 return -1;
84 bstream->bufp = (unsigned char *) &bstream->buf;
85 bstream->nbuf = n;
86 bstream->source += n;
87 }
88
89 b = *bstream->bufp++;
90 bstream->nbuf--;
91 bstream->ntotal--;
92 return b;
93}
94
95
96/* uwx_unget_byte: push a byte back onto the byte stream */
97
98int uwx_unget_byte(struct uwx_bstream *bstream, int b)
99{
100 bstream->peekc = b;
101 return 0;
102}
103
104
105/* uwx_get_uleb128: read a ULEB128 value from the byte stream */
106
107int uwx_get_uleb128(struct uwx_bstream *bstream, uint64_t *valp)
108{
109 uint64_t val;
110 int i;
111 int b;
112
113 b = uwx_get_byte(bstream);
114 val = (uint64_t)(b & 0x7f) << 56;
115 for (i = 0; i < 8; i++) {
116 val = val >> 7;
117 if (b & 0x80) {
118 b = uwx_get_byte(bstream);
119 val |= (uint64_t)(b & 0x7f) << 56;
120 }
121 }
122 if (b & 0x80) {
123 b = uwx_get_byte(bstream);
124 val |= (uint64_t)(b & 0x7f) << 63;
125 }
126 if (b & 0x80)
127 return -1;
128 *valp = val;
129 return 0;
130}
131
132#if 0
133int uwx_get_uleb128_alt(struct uwx_bstream *bstream, uint64_t *valp)
134{
135 uint64_t val;
136 int b;
137
138 b = uwx_get_byte(bstream);
139 val = b & 0x7f;
140 if (b & 0x80) {
141 b = uwx_get_byte(bstream);
142 val |= (uint64_t)(b & 0x7f) << 7;
143 if (b & 0x80) {
144 b = uwx_get_byte(bstream);
145 val |= (uint64_t)(b & 0x7f) << 14;
146 if (b & 0x80) {
147 b = uwx_get_byte(bstream);
148 val |= (uint64_t)(b & 0x7f) << 21;
149 if (b & 0x80) {
150 b = uwx_get_byte(bstream);
151 val |= (uint64_t)(b & 0x7f) << 28;
152 if (b & 0x80) {
153 b = uwx_get_byte(bstream);
154 val |= (uint64_t)(b & 0x7f) << 35;
155 if (b & 0x80) {
156 b = uwx_get_byte(bstream);
157 val |= (uint64_t)(b & 0x7f) << 42;
158 if (b & 0x80) {
159 b = uwx_get_byte(bstream);
160 val |= (uint64_t)(b & 0x7f) << 49;
161 if (b & 0x80) {
162 b = uwx_get_byte(bstream);
163 val |= (uint64_t)(b & 0x7f) << 56;
164 if (b & 0x80) {
165 b = uwx_get_byte(bstream);
166 val |= (uint64_t)(b & 0x7f) << 63;
167 if (b & 0x80)
168 return -1;
169 }
170 }
171 }
172 }
173 }
174 }
175 }
176 }
177 }
178 *valp = val;
179 return 0;
180}
181#endif