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comparison gdb_remote.c @ 456:249d24973682

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Initial work on GDB remote debugging support
author Mike Pavone <pavone@retrodev.com>
date Wed, 04 Sep 2013 19:34:19 -0700
parents
children 140af5509ce7
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455:be9c7b3e25ee 456:249d24973682
1 #include "blastem.h"
2 #include <unistd.h>
3 #include <fcntl.h>
4 #include <stddef.h>
5 #include <stdlib.h>
6 #include <stdio.h>
7
8 #define INITIAL_BUFFER_SIZE 4096
9
10 char * buf = NULL;
11 char * curbuf = NULL;
12 size_t bufsize;
13 int cont = 0;
14 int expect_break_response=0;
15 uint32_t resume_pc;
16
17 void gdb_debug_enter(genesis_context * gen, uint32_t pc)
18 {
19 resume_pc = pc;
20 while(!cont)
21 {
22 }
23 cont = 0;
24 }
25
26 void gdb_run_command(genesis_context * gen, char * command)
27 {
28 switch(*command)
29 {
30 case 'c':
31 if (*(command+1) != 0) {
32 resume_pc =
33 }
34 cont = 1;
35 expect_break_response = 1;
36 break;
37 case 's':
38
39 }
40 }
41
42 void gdb_run_commands(genesis_context * gen)
43 {
44 int enter_debugger = 0;
45 char * cur = buf;
46 while(cur < curbuf);
47 {
48 if(*cur == '$') {
49 cur++
50 char * start = cur;
51 while (cur < curbuf && *cur != '#') {
52 cur++;
53 }
54 if (*cur == '#') {
55 //check to make sure we've received the checksum bytes
56 if (curbuf-cur >= 2) {
57 //TODO: verify checksum
58 //Null terminate payload
59 //send acknowledgement
60 write(FILENO_STDOUT, "+", 1);
61 gdb_run_command(genesis_context * gen, start);
62 cur += 2;
63 } else {
64 cur = start - 1;
65 break;
66 }
67 } else {
68 cur = start - 1;
69 break;
70 }
71 } else {
72 if (*cur == 0x03) {
73 enter_debugger = 1;
74 }
75 cur++;
76 }
77 }
78
79 //FIXME
80 if (consumed == curbuf-buf) {
81 curbuf = buf;
82 } else if (consumed > 0) {
83 memmove(buf, buf + consumed, curbuf - buf - consumed);
84 curbuf -= consumed;
85 }
86 }
87
88 void gdb_command_poll(genesis_context * gen)
89 {
90 for(;;)
91 {
92 if (curbuf == buf + bufsize) {
93 //buffer is full, expand it
94 bufsize *= 2;
95 buf = realloc(buf, bufsize);
96 if (!buf) {
97 fprintf(stderr, "Failed to grow GDB command buffer to %d bytes\n", (int)bufsize);
98 exit(1);
99 }
100 curbuf = buf + bufsize/2;
101 }
102 int numread = read(STDIN_FILENO, buf, bufsize - (curbuf-buf));
103 if (numread < 0) {
104 if (errno == EAGAIN || errno == EWOULDBLOCK) {
105 return;
106 } else {
107 fprintf(stderr, "Error %d while reading GDB commands from stdin", errno);
108 exit(1);
109 }
110 } else if (numread == 0) {
111 exit(0);
112 }
113 gdb_run_commands(genesis_context * gen);
114 }
115 }
116
117 void gdb_remote_init()
118 {
119 fcntl(STDIN_FILENO, FD_SETFL, O_NONBLOCK);
120 buf = malloc(INITIAL_BUFFER_SIZE);
121 curbuf = buf;
122 bufzie = INITIAL_BUFFER_SIZE;
123 }