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root/cebix/mon/src/mon_6502.cpp
Revision: 1.5
Committed: 2000-09-25T12:44:31Z (24 years, 1 month ago) by cebix
Branch: MAIN
Changes since 1.4: +1 -1 lines
Log Message: 
- replaced 680x0 and 80x86 disassemblers with the ones from GNU binutils
- 680x0 disassembler shows symbolic MacOS low memory globals

File Contents

# User Rev Content
1 cebix 1.1 /*
2     * mon_6502.cpp - 6502 disassembler
3     *
4 cebix 1.4 * mon (C) 1997-2000 Christian Bauer, Marc Hellwig
5 cebix 1.2 *
6     * This program is free software; you can redistribute it and/or modify
7     * it under the terms of the GNU General Public License as published by
8     * the Free Software Foundation; either version 2 of the License, or
9     * (at your option) any later version.
10     *
11     * This program is distributed in the hope that it will be useful,
12     * but WITHOUT ANY WARRANTY; without even the implied warranty of
13     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14     * GNU General Public License for more details.
15     *
16     * You should have received a copy of the GNU General Public License
17     * along with this program; if not, write to the Free Software
18     * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 cebix 1.1 */
20    
21 cebix 1.2 #include "sysdeps.h"
22 cebix 1.1
23     #include "mon.h"
24 cebix 1.5 #include "mon_disass.h"
25 cebix 1.1
26    
27     // Addressing modes
28     enum {
29     A_IMPL,
30     A_ACCU, // A
31     A_IMM, // #zz
32     A_REL, // Branches
33     A_ZERO, // zz
34     A_ZEROX, // zz,x
35     A_ZEROY, // zz,y
36     A_ABS, // zzzz
37     A_ABSX, // zzzz,x
38     A_ABSY, // zzzz,y
39     A_IND, // (zzzz)
40     A_INDX, // (zz,x)
41     A_INDY // (zz),y
42     };
43    
44     // Mnemonics
45     enum {
46     M_ADC, M_AND, M_ASL, M_BCC, M_BCS, M_BEQ, M_BIT, M_BMI, M_BNE, M_BPL,
47     M_BRK, M_BVC, M_BVS, M_CLC, M_CLD, M_CLI, M_CLV, M_CMP, M_CPX, M_CPY,
48     M_DEC, M_DEX, M_DEY, M_EOR, M_INC, M_INX, M_INY, M_JMP, M_JSR, M_LDA,
49     M_LDX, M_LDY, M_LSR, M_NOP, M_ORA, M_PHA, M_PHP, M_PLA, M_PLP, M_ROL,
50     M_ROR, M_RTI, M_RTS, M_SBC, M_SEC, M_SED, M_SEI, M_STA, M_STX, M_STY,
51     M_TAX, M_TAY, M_TSX, M_TXA, M_TXS, M_TYA,
52    
53     M_ILLEGAL, // Undocumented opcodes start here
54    
55     M_IANC, M_IANE, M_IARR, M_IASR, M_IDCP, M_IISB, M_IJAM, M_INOP, M_ILAS,
56     M_ILAX, M_ILXA, M_IRLA, M_IRRA, M_ISAX, M_ISBC, M_ISBX, M_ISHA, M_ISHS,
57     M_ISHX, M_ISHY, M_ISLO, M_ISRE,
58    
59     M_MAXIMUM // Highest element
60     };
61    
62     // Mnemonic for each opcode
63     static const char mnemonic[256] = {
64     M_BRK , M_ORA , M_IJAM, M_ISLO, M_INOP, M_ORA, M_ASL , M_ISLO, // 00
65     M_PHP , M_ORA , M_ASL , M_IANC, M_INOP, M_ORA, M_ASL , M_ISLO,
66     M_BPL , M_ORA , M_IJAM, M_ISLO, M_INOP, M_ORA, M_ASL , M_ISLO, // 10
67     M_CLC , M_ORA , M_INOP, M_ISLO, M_INOP, M_ORA, M_ASL , M_ISLO,
68     M_JSR , M_AND , M_IJAM, M_IRLA, M_BIT , M_AND, M_ROL , M_IRLA, // 20
69     M_PLP , M_AND , M_ROL , M_IANC, M_BIT , M_AND, M_ROL , M_IRLA,
70     M_BMI , M_AND , M_IJAM, M_IRLA, M_INOP, M_AND, M_ROL , M_IRLA, // 30
71     M_SEC , M_AND , M_INOP, M_IRLA, M_INOP, M_AND, M_ROL , M_IRLA,
72     M_RTI , M_EOR , M_IJAM, M_ISRE, M_INOP, M_EOR, M_LSR , M_ISRE, // 40
73     M_PHA , M_EOR , M_LSR , M_IASR, M_JMP , M_EOR, M_LSR , M_ISRE,
74     M_BVC , M_EOR , M_IJAM, M_ISRE, M_INOP, M_EOR, M_LSR , M_ISRE, // 50
75     M_CLI , M_EOR , M_INOP, M_ISRE, M_INOP, M_EOR, M_LSR , M_ISRE,
76     M_RTS , M_ADC , M_IJAM, M_IRRA, M_INOP, M_ADC, M_ROR , M_IRRA, // 60
77     M_PLA , M_ADC , M_ROR , M_IARR, M_JMP , M_ADC, M_ROR , M_IRRA,
78     M_BVS , M_ADC , M_IJAM, M_IRRA, M_INOP, M_ADC, M_ROR , M_IRRA, // 70
79     M_SEI , M_ADC , M_INOP, M_IRRA, M_INOP, M_ADC, M_ROR , M_IRRA,
80     M_INOP, M_STA , M_INOP, M_ISAX, M_STY , M_STA, M_STX , M_ISAX, // 80
81     M_DEY , M_INOP, M_TXA , M_IANE, M_STY , M_STA, M_STX , M_ISAX,
82     M_BCC , M_STA , M_IJAM, M_ISHA, M_STY , M_STA, M_STX , M_ISAX, // 90
83     M_TYA , M_STA , M_TXS , M_ISHS, M_ISHY, M_STA, M_ISHX, M_ISHA,
84     M_LDY , M_LDA , M_LDX , M_ILAX, M_LDY , M_LDA, M_LDX , M_ILAX, // a0
85     M_TAY , M_LDA , M_TAX , M_ILXA, M_LDY , M_LDA, M_LDX , M_ILAX,
86     M_BCS , M_LDA , M_IJAM, M_ILAX, M_LDY , M_LDA, M_LDX , M_ILAX, // b0
87     M_CLV , M_LDA , M_TSX , M_ILAS, M_LDY , M_LDA, M_LDX , M_ILAX,
88     M_CPY , M_CMP , M_INOP, M_IDCP, M_CPY , M_CMP, M_DEC , M_IDCP, // c0
89     M_INY , M_CMP , M_DEX , M_ISBX, M_CPY , M_CMP, M_DEC , M_IDCP,
90     M_BNE , M_CMP , M_IJAM, M_IDCP, M_INOP, M_CMP, M_DEC , M_IDCP, // d0
91     M_CLD , M_CMP , M_INOP, M_IDCP, M_INOP, M_CMP, M_DEC , M_IDCP,
92     M_CPX , M_SBC , M_INOP, M_IISB, M_CPX , M_SBC, M_INC , M_IISB, // e0
93     M_INX , M_SBC , M_NOP , M_ISBC, M_CPX , M_SBC, M_INC , M_IISB,
94     M_BEQ , M_SBC , M_IJAM, M_IISB, M_INOP, M_SBC, M_INC , M_IISB, // f0
95     M_SED , M_SBC , M_INOP, M_IISB, M_INOP, M_SBC, M_INC , M_IISB
96     };
97    
98     // Addressing mode for each opcode
99     static const char adr_mode[256] = {
100     A_IMPL, A_INDX, A_IMPL, A_INDX, A_ZERO , A_ZERO , A_ZERO , A_ZERO, // 00
101     A_IMPL, A_IMM , A_ACCU, A_IMM , A_ABS , A_ABS , A_ABS , A_ABS,
102     A_REL , A_INDY, A_IMPL, A_INDY, A_ZEROX, A_ZEROX, A_ZEROX, A_ZEROX, // 10
103     A_IMPL, A_ABSY, A_IMPL, A_ABSY, A_ABSX , A_ABSX , A_ABSX , A_ABSX,
104     A_ABS , A_INDX, A_IMPL, A_INDX, A_ZERO , A_ZERO , A_ZERO , A_ZERO, // 20
105     A_IMPL, A_IMM , A_ACCU, A_IMM , A_ABS , A_ABS , A_ABS , A_ABS,
106     A_REL , A_INDY, A_IMPL, A_INDY, A_ZEROX, A_ZEROX, A_ZEROX, A_ZEROX, // 30
107     A_IMPL, A_ABSY, A_IMPL, A_ABSY, A_ABSX , A_ABSX , A_ABSX , A_ABSX,
108     A_IMPL, A_INDX, A_IMPL, A_INDX, A_ZERO , A_ZERO , A_ZERO , A_ZERO, // 40
109     A_IMPL, A_IMM , A_ACCU, A_IMM , A_ABS , A_ABS , A_ABS , A_ABS,
110     A_REL , A_INDY, A_IMPL, A_INDY, A_ZEROX, A_ZEROX, A_ZEROX, A_ZEROX, // 50
111     A_IMPL, A_ABSY, A_IMPL, A_ABSY, A_ABSX , A_ABSX , A_ABSX , A_ABSX,
112     A_IMPL, A_INDX, A_IMPL, A_INDX, A_ZERO , A_ZERO , A_ZERO , A_ZERO, // 60
113     A_IMPL, A_IMM , A_ACCU, A_IMM , A_IND , A_ABS , A_ABS , A_ABS,
114     A_REL , A_INDY, A_IMPL, A_INDY, A_ZEROX, A_ZEROX, A_ZEROX, A_ZEROX, // 70
115     A_IMPL, A_ABSY, A_IMPL, A_ABSY, A_ABSX , A_ABSX , A_ABSX , A_ABSX,
116     A_IMM , A_INDX, A_IMM , A_INDX, A_ZERO , A_ZERO , A_ZERO , A_ZERO, // 80
117     A_IMPL, A_IMM , A_IMPL, A_IMM , A_ABS , A_ABS , A_ABS , A_ABS,
118     A_REL , A_INDY, A_IMPL, A_INDY, A_ZEROX, A_ZEROX, A_ZEROY, A_ZEROY, // 90
119     A_IMPL, A_ABSY, A_IMPL, A_ABSY, A_ABSX , A_ABSX , A_ABSY , A_ABSY,
120     A_IMM , A_INDX, A_IMM , A_INDX, A_ZERO , A_ZERO , A_ZERO , A_ZERO, // a0
121     A_IMPL, A_IMM , A_IMPL, A_IMM , A_ABS , A_ABS , A_ABS , A_ABS,
122     A_REL , A_INDY, A_IMPL, A_INDY, A_ZEROX, A_ZEROX, A_ZEROY, A_ZEROY, // b0
123     A_IMPL, A_ABSY, A_IMPL, A_ABSY, A_ABSX , A_ABSX , A_ABSY , A_ABSY,
124     A_IMM , A_INDX, A_IMM , A_INDX, A_ZERO , A_ZERO , A_ZERO , A_ZERO, // c0
125     A_IMPL, A_IMM , A_IMPL, A_IMM , A_ABS , A_ABS , A_ABS , A_ABS,
126     A_REL , A_INDY, A_IMPL, A_INDY, A_ZEROX, A_ZEROX, A_ZEROX, A_ZEROX, // d0
127     A_IMPL, A_ABSY, A_IMPL, A_ABSY, A_ABSX , A_ABSX , A_ABSX , A_ABSX,
128     A_IMM , A_INDX, A_IMM , A_INDX, A_ZERO , A_ZERO , A_ZERO , A_ZERO, // e0
129     A_IMPL, A_IMM , A_IMPL, A_IMM , A_ABS , A_ABS , A_ABS , A_ABS,
130     A_REL , A_INDY, A_IMPL, A_INDY, A_ZEROX, A_ZEROX, A_ZEROX, A_ZEROX, // f0
131     A_IMPL, A_ABSY, A_IMPL, A_ABSY, A_ABSX , A_ABSX , A_ABSX , A_ABSX
132     };
133    
134     // Chars for each mnemonic
135     static const char mnem_1[] = "aaabbbbbbbbbbcccccccdddeiiijjllllnopppprrrrssssssstttttt?aaaadijnlllrrsssssssss";
136     static const char mnem_2[] = "dnscceimnprvvllllmppeeeonnnmsdddsorhhlloottbeeetttaasxxy?nnrscsaoaaxlrabbhhhhlr";
137     static const char mnem_3[] = "cdlcsqtielkcscdivpxycxyrcxypraxyrpaapaplrisccdiaxyxyxasa?cerrpbmpsxaaaxcxasxyoe";
138    
139     // Instruction length for each addressing mode
140     static const char adr_length[] = {1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 2, 2};
141    
142    
143     /*
144     * Disassemble one instruction, return number of bytes
145     */
146    
147     int disass_6502(FILE *f, uint32 adr, uint8 op, uint8 lo, uint8 hi)
148     {
149     char mode = adr_mode[op], mnem = mnemonic[op];
150    
151     // Display instruction bytes in hex
152     switch (adr_length[mode]) {
153     case 1:
154     fprintf(f, "%02x\t\t", op);
155     break;
156    
157     case 2:
158     fprintf(f, "%02x %02x\t\t", op, lo);
159     break;
160    
161     case 3:
162     fprintf(f, "%02x %02x %02x\t", op, lo, hi);
163     break;
164     }
165    
166     // Tag undocumented opcodes with an asterisk
167     if (mnem > M_ILLEGAL)
168     fputc('*', f);
169     else
170     fputc(' ', f);
171    
172     // Print mnemonic
173     fprintf(f, "%c%c%c ", mnem_1[mnem], mnem_2[mnem], mnem_3[mnem]);
174    
175     // Print argument
176     switch (mode) {
177     case A_IMPL:
178     break;
179    
180     case A_ACCU:
181     fprintf(f, "a");
182     break;
183    
184     case A_IMM:
185     fprintf(f, "#$%02x", lo);
186     break;
187    
188     case A_REL:
189 cebix 1.3 fprintf(f, "$%04x", (adr + 2) + (int8)lo);
190 cebix 1.1 break;
191    
192     case A_ZERO:
193     fprintf(f, "$%02x", lo);
194     break;
195    
196     case A_ZEROX:
197     fprintf(f, "$%02x,x", lo);
198     break;
199    
200     case A_ZEROY:
201     fprintf(f, "$%02x,y", lo);
202     break;
203    
204     case A_ABS:
205     fprintf(f, "$%04x", (hi << 8) | lo);
206     break;
207    
208     case A_ABSX:
209     fprintf(f, "$%04x,x", (hi << 8) | lo);
210     break;
211    
212     case A_ABSY:
213     fprintf(f, "$%04x,y", (hi << 8) | lo);
214     break;
215    
216     case A_IND:
217     fprintf(f, "($%04x)", (hi << 8) | lo);
218     break;
219    
220     case A_INDX:
221     fprintf(f, "($%02x,x)", lo);
222     break;
223    
224     case A_INDY:
225     fprintf(f, "($%02x),y", lo);
226     break;
227     }
228    
229     fputc('\n', f);
230     return adr_length[mode];
231     }