1 | /*****************************************************************************/ |
2 | /* */ |
3 | /* code.c */ |
4 | /* */ |
5 | /* Binary code management */ |
6 | /* */ |
7 | /* */ |
8 | /* */ |
9 | /* (C) 2000-2003 Ullrich von Bassewitz */ |
10 | /* Roemerstrasse 52 */ |
11 | /* D-70794 Filderstadt */ |
12 | /* EMail: uz@cc65.org */ |
13 | /* */ |
14 | /* */ |
15 | /* This software is provided 'as-is', without any expressed or implied */ |
16 | /* warranty. In no event will the authors be held liable for any damages */ |
17 | /* arising from the use of this software. */ |
18 | /* */ |
19 | /* Permission is granted to anyone to use this software for any purpose, */ |
20 | /* including commercial applications, and to alter it and redistribute it */ |
21 | /* freely, subject to the following restrictions: */ |
22 | /* */ |
23 | /* 1. The origin of this software must not be misrepresented; you must not */ |
24 | /* claim that you wrote the original software. If you use this software */ |
25 | /* in a product, an acknowledgment in the product documentation would be */ |
26 | /* appreciated but is not required. */ |
27 | /* 2. Altered source versions must be plainly marked as such, and must not */ |
28 | /* be misrepresented as being the original software. */ |
29 | /* 3. This notice may not be removed or altered from any source */ |
30 | /* distribution. */ |
31 | /* */ |
32 | /*****************************************************************************/ |
33 | |
34 | |
35 | |
36 | #include <stdio.h> |
37 | #include <string.h> |
38 | #include <errno.h> |
39 | |
40 | /* common */ |
41 | #include "check.h" |
42 | |
43 | /* da65 */ |
44 | #include "code.h" |
45 | #include "error.h" |
46 | #include "global.h" |
47 | |
48 | |
49 | |
50 | /*****************************************************************************/ |
51 | /* Data */ |
52 | /*****************************************************************************/ |
53 | |
54 | |
55 | |
56 | unsigned char CodeBuf [0x10000]; /* Code buffer */ |
57 | unsigned long CodeStart; /* Start address */ |
58 | unsigned long CodeEnd; /* End address */ |
59 | unsigned long PC; /* Current PC */ |
60 | |
61 | |
62 | |
63 | /*****************************************************************************/ |
64 | /* Code */ |
65 | /*****************************************************************************/ |
66 | |
67 | |
68 | |
69 | void LoadCode (void) |
70 | /* Load the code from the given file */ |
71 | { |
72 | long Count, MaxCount, Size; |
73 | FILE* F; |
74 | |
75 | |
76 | PRECONDITION (StartAddr < 0x10000); |
77 | |
78 | /* Open the file */ |
79 | F = fopen (InFile, "rb" ); |
80 | if (F == 0) { |
81 | Error ("Cannot open '%s': %s" , InFile, strerror (errno)); |
82 | } |
83 | |
84 | /* Seek to the end to get the size of the file */ |
85 | if (fseek (F, 0, SEEK_END) != 0) { |
86 | Error ("Cannot seek on file '%s': %s" , InFile, strerror (errno)); |
87 | } |
88 | Size = ftell (F); |
89 | |
90 | /* The input offset must be smaller than the size */ |
91 | if (InputOffs >= 0) { |
92 | if (InputOffs >= Size) { |
93 | Error ("Input offset is greater than file size" ); |
94 | } |
95 | } else { |
96 | /* Use a zero offset */ |
97 | InputOffs = 0; |
98 | } |
99 | |
100 | /* Seek to the input offset and correct size to contain the remainder of |
101 | ** the file. |
102 | */ |
103 | if (fseek (F, InputOffs, SEEK_SET) != 0) { |
104 | Error ("Cannot seek on file '%s': %s" , InFile, strerror (errno)); |
105 | } |
106 | Size -= InputOffs; |
107 | |
108 | /* Limit the size to the maximum input size if one is given */ |
109 | if (InputSize >= 0) { |
110 | if (InputSize > Size) { |
111 | Error ("Input size is greater than what is available" ); |
112 | } |
113 | Size = InputSize; |
114 | } |
115 | |
116 | /* If the start address was not given, set it so that the code loads to |
117 | ** 0x10000 - Size. This is a reasonable default assuming that the file |
118 | ** is a ROM that contains the hardware vectors at $FFFA. |
119 | */ |
120 | if (StartAddr < 0) { |
121 | if (Size > 0x10000) { |
122 | StartAddr = 0; |
123 | } else { |
124 | StartAddr = 0x10000 - Size; |
125 | } |
126 | } |
127 | |
128 | /* Calculate the maximum code size */ |
129 | MaxCount = 0x10000 - StartAddr; |
130 | |
131 | /* Check if the size is larger than what we can read */ |
132 | if (Size == 0) { |
133 | Error ("Nothing to read from input file '%s'" , InFile); |
134 | } |
135 | if (Size > MaxCount) { |
136 | Warning ("File '%s' is too large, ignoring %ld bytes" , |
137 | InFile, Size - MaxCount); |
138 | } else if (MaxCount > Size) { |
139 | MaxCount = (unsigned) Size; |
140 | } |
141 | |
142 | /* Read from the file and remember the number of bytes read */ |
143 | Count = fread (CodeBuf + StartAddr, 1, MaxCount, F); |
144 | if (ferror (F) || Count != MaxCount) { |
145 | Error ("Error reading from '%s': %s" , InFile, strerror (errno)); |
146 | } |
147 | |
148 | /* Close the file */ |
149 | fclose (F); |
150 | |
151 | /* Set the buffer variables */ |
152 | CodeStart = PC = StartAddr; |
153 | CodeEnd = CodeStart + Count - 1; /* CodeEnd is inclusive */ |
154 | } |
155 | |
156 | |
157 | |
158 | unsigned char GetCodeByte (unsigned Addr) |
159 | /* Get a byte from the given address */ |
160 | { |
161 | PRECONDITION (Addr <= CodeEnd); |
162 | return CodeBuf [Addr]; |
163 | } |
164 | |
165 | |
166 | |
167 | unsigned GetCodeDByte (unsigned Addr) |
168 | /* Get a dbyte from the given address */ |
169 | { |
170 | unsigned Lo = GetCodeByte (Addr); |
171 | unsigned Hi = GetCodeByte (Addr+1); |
172 | return (Lo <<8) | Hi; |
173 | } |
174 | |
175 | |
176 | |
177 | unsigned GetCodeWord (unsigned Addr) |
178 | /* Get a word from the given address */ |
179 | { |
180 | unsigned Lo = GetCodeByte (Addr); |
181 | unsigned Hi = GetCodeByte (Addr+1); |
182 | return Lo | (Hi << 8); |
183 | } |
184 | |
185 | |
186 | |
187 | unsigned long GetCodeDWord (unsigned Addr) |
188 | /* Get a dword from the given address */ |
189 | { |
190 | unsigned long Lo = GetCodeWord (Addr); |
191 | unsigned long Hi = GetCodeWord (Addr+2); |
192 | return Lo | (Hi << 16); |
193 | } |
194 | |
195 | |
196 | |
197 | unsigned GetRemainingBytes (void) |
198 | /* Return the number of remaining code bytes */ |
199 | { |
200 | if (CodeEnd >= PC) { |
201 | return (CodeEnd - PC + 1); |
202 | } else { |
203 | return 0; |
204 | } |
205 | } |
206 | |
207 | |
208 | |
209 | int CodeLeft (void) |
210 | /* Return true if there are code bytes left */ |
211 | { |
212 | return (PC <= CodeEnd); |
213 | } |
214 | |
215 | |
216 | |
217 | void ResetCode (void) |
218 | /* Reset the code input to start over for the next pass */ |
219 | { |
220 | PC = CodeStart; |
221 | } |
222 | |