nkeynes@998: /**
nkeynes@1020:  * $Id$
nkeynes@998:  * 
nkeynes@998:  * GDB RDP server stub - SH4 + ARM
nkeynes@998:  *
nkeynes@998:  * Copyright (c) 2009 Nathan Keynes.
nkeynes@998:  *
nkeynes@998:  * This program is free software; you can redistribute it and/or modify
nkeynes@998:  * it under the terms of the GNU General Public License as published by
nkeynes@998:  * the Free Software Foundation; either version 2 of the License, or
nkeynes@998:  * (at your option) any later version.
nkeynes@998:  *
nkeynes@998:  * This program is distributed in the hope that it will be useful,
nkeynes@998:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
nkeynes@998:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nkeynes@998:  * GNU General Public License for more details.
nkeynes@998:  */
nkeynes@998: 
nkeynes@998: 
nkeynes@998: #include <errno.h>
nkeynes@998: #include <stdio.h>
nkeynes@998: #include <stdlib.h>
nkeynes@998: #include <stdarg.h>
nkeynes@998: #include <string.h>
nkeynes@998: #include <unistd.h>
nkeynes@998: #include <glib.h>
nkeynes@998: #include <arpa/inet.h>
nkeynes@998: #include "lxdream.h"
nkeynes@998: #include "dreamcast.h"
nkeynes@1077: #include "ioutil.h"
nkeynes@998: #include "cpu.h"
nkeynes@998: 
nkeynes@998: #define DEFAULT_BUFFER_SIZE 1024
nkeynes@998: #define BUFFER_SIZE_MARGIN 32
nkeynes@998: #define MAX_BUFFER_SIZE 65536
nkeynes@998: 
nkeynes@998: /* These are just local interpretations - they're not interpreted by GDB
nkeynes@998:  * in any way shape or form.
nkeynes@998:  */
nkeynes@998: #define GDB_ERROR_FORMAT 1 /* Badly formatted command */
nkeynes@998: #define GDB_ERROR_INVAL  2 /* Invalid data */
nkeynes@998: #define GDB_ERROR_FAIL   3 /* Command failed */
nkeynes@998: struct gdb_server {
nkeynes@998:     cpu_desc_t cpu;
nkeynes@998:     gboolean mmu;
nkeynes@998:     int fd;
nkeynes@998:     const gchar *peer_name;
nkeynes@998:     char *buf;
nkeynes@998:     int buf_size;
nkeynes@998:     int buf_posn;
nkeynes@998: };
nkeynes@998: 
nkeynes@998: void gdb_server_free( gpointer data )
nkeynes@998: {
nkeynes@998:     struct gdb_server *server = (struct gdb_server *)data;
nkeynes@998:     free((char *)server->peer_name);
nkeynes@998:     free(server->buf);
nkeynes@998:     free(data);
nkeynes@998: }
nkeynes@998: 
nkeynes@998: int gdb_checksum( char *data, int length )
nkeynes@998: {
nkeynes@998:     int i;
nkeynes@998:     int result = 0;
nkeynes@998:     for( i=0; i<length; i++ ) 
nkeynes@998:         result += data[i];
nkeynes@998:     result &= 0xFF;
nkeynes@998:     return result;
nkeynes@998: }
nkeynes@998: 
nkeynes@998: void gdb_send_frame( struct gdb_server *server, char *data, int length )
nkeynes@998: {
nkeynes@998:     char out[length+5];
nkeynes@998:     snprintf( out, length+5, "$%.*s#%02x", length, data, gdb_checksum(data,length) ); 
nkeynes@998:     write( server->fd, out, length+4 );
nkeynes@998: }
nkeynes@998: 
nkeynes@998: /**
nkeynes@998:  * Send bulk data (ie memory dump) as hex, with optional string prefix.
nkeynes@998:  * Saves double copying when going through gdb_send_frame.
nkeynes@998:  */ 
nkeynes@998: void gdb_send_hex_data( struct gdb_server *server, char *prefix, unsigned char *data, int datalen )
nkeynes@998: {
nkeynes@998:    int prefixlen = 0;
nkeynes@998:    if( prefix != NULL )
nkeynes@998:        prefixlen = strlen(prefix);
nkeynes@998:    int totallen = datalen*2 + prefixlen + 4;
nkeynes@998:    char out[totallen+1];
nkeynes@998:    char *p = &out[1];
nkeynes@998:    int i;
nkeynes@998:    
nkeynes@998:    out[0] = '$';
nkeynes@998:    if( prefix != NULL ) {
nkeynes@998:        p += sprintf( p, "%s", prefix );
nkeynes@998:    }
nkeynes@998:    for( i=0; i<datalen; i++ ) {
nkeynes@998:        p += sprintf( p, "%02x", data[i] );
nkeynes@998:    }
nkeynes@998:    *p++ = '#';
nkeynes@998:    sprintf( p, "%02x", gdb_checksum(out+1, datalen*2 + prefixlen) );
nkeynes@998:    write( server->fd, out, totallen );
nkeynes@998: }
nkeynes@998: 
nkeynes@998: /**
nkeynes@998:  * Parse bulk hex data - buffer should be at least datalen/2 bytes long
nkeynes@998:  */
nkeynes@1025: size_t gdb_read_hex_data( struct gdb_server *server, unsigned char *buf, char *data, int datalen )
nkeynes@998: {
nkeynes@998:     char *p = data;
nkeynes@998:     for( int i=0; i<datalen/2; i++ ) {
nkeynes@998:         int v;
nkeynes@998:         sscanf( p, "%02x", &v );
nkeynes@998:         buf[i] = v;
nkeynes@998:         p += 2;
nkeynes@998:     }    
nkeynes@998:     return datalen/2;
nkeynes@998: }
nkeynes@998: 
nkeynes@998: /**
nkeynes@998:  * Parse bulk binary-encoded data - $, #, 0x7D are encoded as 0x7d, char ^ 0x20. 
nkeynes@998:  * Buffer should be at least datalen bytes longs.
nkeynes@998:  */
nkeynes@1025: size_t gdb_read_binary_data( struct gdb_server *server, unsigned char *buf, char *data, int datalen )
nkeynes@998: {
nkeynes@998:     unsigned char *q = buf;
nkeynes@998:     for( int i=0, j=0; i<datalen; i++ ) {
nkeynes@998:         if( data[i] == 0x7D ) {
nkeynes@998:             if( i == datalen-1 ) {
nkeynes@998:                 return -1;
nkeynes@998:             } else {
nkeynes@998:                 *q++ = data[++i] ^ 0x20;
nkeynes@998:             }
nkeynes@998:         } else {
nkeynes@998:             *q++ = data[i];
nkeynes@998:         }
nkeynes@998:     }
nkeynes@998:     return q - buf;
nkeynes@998: }
nkeynes@998: 
nkeynes@998: void gdb_printf_frame( struct gdb_server *server, char *msg, ... )
nkeynes@998: {
nkeynes@998:     va_list va;
nkeynes@998:     
nkeynes@998:     va_start(va,msg);
nkeynes@998:     int len = vsnprintf( NULL, 0, msg, va );
nkeynes@998:     char buf[len+1];
nkeynes@998:     vsnprintf( buf, len+1, msg, va);
nkeynes@998:     va_end(va);
nkeynes@998:     gdb_send_frame( server, buf, len );
nkeynes@998: }
nkeynes@998: 
nkeynes@998: int gdb_print_registers( struct gdb_server *server, char *buf, int buflen, int firstreg, int regcount )
nkeynes@998: {
nkeynes@998:     int i;
nkeynes@998:     char *p = buf;
nkeynes@998:     char *endp = buf + (buflen-8);
nkeynes@998:     for( i=firstreg; i < firstreg + regcount && p < endp; i++ ) {
nkeynes@998:         uint8_t *val = server->cpu->get_register(i);
nkeynes@998:         if( val == NULL ) {
nkeynes@998:             sprintf( p, "00000000" );
nkeynes@998:         } else {
nkeynes@998:             sprintf( p, "%02x%02x%02x%02x", val[0], val[1], val[2], val[3] );
nkeynes@998:         }
nkeynes@998:         p += 8;
nkeynes@998:     }
nkeynes@998:     
nkeynes@998:     return i - firstreg;
nkeynes@998: }
nkeynes@998: 
nkeynes@998: void gdb_set_registers( struct gdb_server *server, char *buf, int firstreg, int regcount )
nkeynes@998: {
nkeynes@998:     int i;
nkeynes@998:     char *p = buf;
nkeynes@998:     for( i=firstreg; i < firstreg + regcount; i++ ) {
nkeynes@998:         uint8_t *val = server->cpu->get_register(i);
nkeynes@1020:         unsigned int a,b,c,d;
nkeynes@998:         if( val != NULL ) {
nkeynes@1020:             sscanf( p, "%02x%02x%02x%02x", &a, &b, &c, &d );
nkeynes@1020:             val[0] = (uint8_t)a;
nkeynes@1020:             val[1] = (uint8_t)b;
nkeynes@1020:             val[2] = (uint8_t)c;
nkeynes@1020:             val[3] = (uint8_t)d;
nkeynes@998:         }
nkeynes@998:         p += 8;
nkeynes@998:     }
nkeynes@998: }
nkeynes@998: 
nkeynes@998: /**
nkeynes@998:  * Send a 2-digit error code. There's no actual definition for any of the codes
nkeynes@998:  * so they're more for our own amusement really.
nkeynes@998:  */
nkeynes@998: void gdb_send_error( struct gdb_server *server, int error )
nkeynes@998: {
nkeynes@998:     char out[4];
nkeynes@998:     snprintf( out, 4, "E%02X", (error&0xFF) );
nkeynes@998:     gdb_send_frame( server, out, 3 );
nkeynes@998: }
nkeynes@998: 
nkeynes@998: void gdb_server_handle_frame( struct gdb_server *server, int command, char *data, int length )
nkeynes@998: {
nkeynes@998:     unsigned int tmp, tmp2, tmp3;
nkeynes@998:     char buf[512];
nkeynes@998:     
nkeynes@998:     switch( command ) {
nkeynes@998:     case '!': /* Enable extended mode */
nkeynes@998:         gdb_send_frame( server, "OK", 2 );
nkeynes@998:         break;
nkeynes@998:     case '?': /* Get stop reason - always return 5 (TRAP) */
nkeynes@998:         gdb_send_frame( server, "S05", 3 );
nkeynes@998:         break;
nkeynes@998:     case 'c': /* Continue */
nkeynes@998:         dreamcast_run();
nkeynes@998:         gdb_send_frame( server, "S05", 3 );
nkeynes@998:         break;
nkeynes@998:     case 'g': /* Read all general registers */
nkeynes@998:         gdb_print_registers( server, buf, sizeof(buf), 0, server->cpu->num_gpr_regs );
nkeynes@998:         gdb_send_frame( server, buf, strlen(buf) );
nkeynes@998:         break;
nkeynes@998:     case 'G': /* Write all general registers */
nkeynes@998:         if( length != server->cpu->num_gpr_regs*8 ) {
nkeynes@998:             gdb_send_error( server, GDB_ERROR_FORMAT );
nkeynes@998:         } else {
nkeynes@998:             gdb_set_registers( server, data, 0, server->cpu->num_gpr_regs );
nkeynes@998:             gdb_send_frame( server, "OK", 2 );
nkeynes@998:         }
nkeynes@998:         break;
nkeynes@998:     case 'H': /* Set thread - only thread 1 is supported here */
nkeynes@998:         if( length < 2 ) {
nkeynes@998:             gdb_send_error( server, GDB_ERROR_FORMAT );
nkeynes@998:         } else {
nkeynes@998:             int thread;
nkeynes@998:             sscanf( data+1, "%d", &thread );
nkeynes@998:             if( thread >= -1 && thread <= 1 ) {
nkeynes@998:                 gdb_send_frame( server, "OK", 2 );
nkeynes@998:             } else {
nkeynes@998:                 gdb_send_error( server, GDB_ERROR_INVAL );
nkeynes@998:             }
nkeynes@998:         }
nkeynes@998:         break;
nkeynes@998:     case 'k': /* kill - do nothing */
nkeynes@998:         gdb_send_frame( server, "", 0 );
nkeynes@998:         break;
nkeynes@998:     case 'm': /* Read memory */
nkeynes@998:         if( sscanf( data, "%x,%x", &tmp, &tmp2 ) != 2 ) {
nkeynes@998:             gdb_send_error( server, GDB_ERROR_FORMAT );
nkeynes@998:         } else {
nkeynes@998:             size_t datalen;
nkeynes@1025:             unsigned char mem[tmp2];
nkeynes@998:             if( server->mmu ) {
nkeynes@998:                 datalen = server->cpu->read_mem_vma(mem, tmp, tmp2);
nkeynes@998:             } else {
nkeynes@998:                 datalen = server->cpu->read_mem_phys(mem, tmp, tmp2);
nkeynes@998:             }
nkeynes@998:             if( datalen == 0 ) {
nkeynes@998:                 gdb_send_error( server, GDB_ERROR_INVAL );
nkeynes@998:             } else {
nkeynes@998:                 gdb_send_hex_data( server, NULL, mem, datalen );
nkeynes@998:             }
nkeynes@998:         }   
nkeynes@998:         break;
nkeynes@998:     case 'M': /* Write memory */
nkeynes@998:         if( sscanf( data, "%x,%x:%n", &tmp, &tmp2, &tmp3 ) != 2 ||
nkeynes@998:                 length-tmp3 != tmp2*2 ) {
nkeynes@998:             gdb_send_error( server, GDB_ERROR_FORMAT );
nkeynes@998:         } else {
nkeynes@998:             size_t len;
nkeynes@1025:             unsigned char mem[tmp2];
nkeynes@998:             len = gdb_read_hex_data( server, mem, data+tmp3, length-tmp3 );
nkeynes@998:             if( len != tmp2 ) {
nkeynes@998:                 gdb_send_error( server, GDB_ERROR_FORMAT );
nkeynes@998:             } else {
nkeynes@998:                 if( server->mmu ) {
nkeynes@998:                     len = server->cpu->write_mem_vma(tmp, mem, tmp2);
nkeynes@998:                 } else {
nkeynes@998:                     len = server->cpu->write_mem_phys(tmp, mem, tmp2);
nkeynes@998:                 }
nkeynes@998:                 if( len != tmp2 ) {
nkeynes@998:                     gdb_send_error( server, GDB_ERROR_INVAL );
nkeynes@998:                 } else {
nkeynes@998:                     gdb_send_frame( server, "OK", 2 );
nkeynes@998:                 }
nkeynes@998:             }
nkeynes@998:         }
nkeynes@998:         break;   
nkeynes@998:     case 'p': /* Read single register */
nkeynes@998:         if( sscanf( data, "%x", &tmp ) != 1 ) {
nkeynes@998:             gdb_send_error( server, GDB_ERROR_FORMAT );
nkeynes@998:         } else if( tmp >= server->cpu->num_gdb_regs ) {
nkeynes@998:             gdb_send_error( server, GDB_ERROR_INVAL );
nkeynes@998:         } else {
nkeynes@998:             gdb_print_registers( server, buf, sizeof(buf), tmp, 1 );
nkeynes@998:             gdb_send_frame( server, buf, 8 );
nkeynes@998:         }
nkeynes@998:         break;
nkeynes@998:     case 'P': /* Write single register. */
nkeynes@998:         if( sscanf( data, "%x=%n", &tmp, &tmp2 ) != 1 || 
nkeynes@998:                 length-tmp2 != 8) {
nkeynes@998:             gdb_send_error( server, GDB_ERROR_FORMAT );
nkeynes@998:         } else if( tmp >= server->cpu->num_gdb_regs ) {
nkeynes@998:             gdb_send_error( server, GDB_ERROR_INVAL );
nkeynes@998:         } else {
nkeynes@998:             gdb_set_registers( server, data+tmp2, tmp, 1 ); 
nkeynes@998:             gdb_send_frame( server, "OK", 2 );
nkeynes@998:         }
nkeynes@998:         break;
nkeynes@998:     case 'q': /* Query data */
nkeynes@998:         if( strcmp( data, "C" ) == 0 ) {
nkeynes@998:             gdb_send_frame( server, "QC1", 3 );
nkeynes@998:         } else if( strcmp( data, "fThreadInfo" ) == 0 ) {
nkeynes@998:             gdb_send_frame( server, "m1", 2 );
nkeynes@998:         } else if( strcmp( data, "sThreadInfo" ) == 0 ) {
nkeynes@998:             gdb_send_frame( server, "l", 1 );
nkeynes@998:         } else if( strncmp( data, "Supported", 9 ) == 0 ) {
nkeynes@998:             gdb_send_frame( server, "PacketSize=4000", 15 );
nkeynes@998:         } else if( strcmp( data, "Symbol::" ) == 0 ) {
nkeynes@998:             gdb_send_frame( server, "OK", 2 );
nkeynes@998:         } else {
nkeynes@998:             gdb_send_frame( server, "", 0 );
nkeynes@998:         }
nkeynes@998:         break;
nkeynes@998:     case 's': /* Single-step */
nkeynes@998:         if( length != 0 ) {
nkeynes@998:             if( sscanf( data, "%x", &tmp ) != 1 ) {
nkeynes@998:                 gdb_send_error( server, GDB_ERROR_FORMAT );
nkeynes@998:             } else {
nkeynes@998:                 *server->cpu->pc = tmp;
nkeynes@998:             }
nkeynes@998:         }
nkeynes@998:         server->cpu->step_func();
nkeynes@998:         gdb_send_frame( server, "S05", 3 );
nkeynes@998:         break;
nkeynes@998:     case 'T': /* Thread alive */
nkeynes@998:         if( sscanf( data, "%x", &tmp ) != 1 ) {
nkeynes@998:             gdb_send_error( server, GDB_ERROR_FORMAT );
nkeynes@998:         } else if( tmp != 1 ) {
nkeynes@998:             gdb_send_error( server, GDB_ERROR_INVAL );
nkeynes@998:         } else {
nkeynes@998:             gdb_send_frame( server, "OK", 2 );
nkeynes@998:         }
nkeynes@998:         break;
nkeynes@998:     case 'v': /* Verbose */
nkeynes@998:         /* Only current one is vCont, which we don't bother supporting
nkeynes@998:          * at the moment, but don't warn about it either */
nkeynes@998:         gdb_send_frame( server, "", 0 );
nkeynes@998:         break;
nkeynes@998:     case 'X': /* Write memory binary */
nkeynes@998:         if( sscanf( data, "%x,%x:%n", &tmp, &tmp2, &tmp3 ) != 2 ) {
nkeynes@998:             gdb_send_error( server, GDB_ERROR_FORMAT );
nkeynes@998:         } else {
nkeynes@1025:             unsigned char mem[length - tmp3];
nkeynes@998:             size_t len = gdb_read_binary_data( server, mem, data + tmp3, length-tmp3 );
nkeynes@998:             if( len != tmp2 ) {
nkeynes@998:                 gdb_send_error( server, GDB_ERROR_FORMAT );
nkeynes@998:             } else {
nkeynes@998:                 if( server->mmu ) {
nkeynes@998:                     len = server->cpu->write_mem_vma(tmp, mem, tmp2);
nkeynes@998:                 } else {
nkeynes@998:                     len = server->cpu->write_mem_phys(tmp, mem, tmp2);
nkeynes@998:                 }
nkeynes@998:                 if( len != tmp2 ) {
nkeynes@998:                     gdb_send_error( server, GDB_ERROR_INVAL );
nkeynes@998:                 } else {
nkeynes@998:                     gdb_send_frame( server, "OK", 2 );
nkeynes@998:                 }
nkeynes@998:             }
nkeynes@998:         }
nkeynes@998:         break;
nkeynes@998:     case 'z': /* Remove Break/watchpoint */
nkeynes@998:         if( sscanf( data, "%d,%x,%x", &tmp, &tmp2, &tmp3 ) != 3 ) {
nkeynes@998:             gdb_send_error( server, GDB_ERROR_FORMAT );
nkeynes@998:         } else {
nkeynes@998:             if( tmp == 0 || tmp == 1 ) { /* soft break or hard break */
nkeynes@998:                 server->cpu->clear_breakpoint( tmp2, BREAK_KEEP );
nkeynes@998:                 gdb_send_frame( server, "OK", 2 );
nkeynes@998:             } else {
nkeynes@998:                 gdb_send_frame( server, "", 0 );
nkeynes@998:             }
nkeynes@998:         }
nkeynes@998:         break;
nkeynes@998:     case 'Z': /* Insert Break/watchpoint */
nkeynes@998:         if( sscanf( data, "%d,%x,%x", &tmp, &tmp2, &tmp3 ) != 3 ) {
nkeynes@998:             gdb_send_error( server, GDB_ERROR_FORMAT );
nkeynes@998:         } else {
nkeynes@998:             if( tmp == 0 || tmp == 1 ) { /* soft break or hard break */
nkeynes@998:                 server->cpu->set_breakpoint( tmp2, BREAK_KEEP );
nkeynes@998:                 gdb_send_frame( server, "OK", 2 );
nkeynes@998:             } else {
nkeynes@998:                 gdb_send_frame( server, "", 0 );
nkeynes@998:             }
nkeynes@998:         }
nkeynes@998:         break;
nkeynes@998:     default:
nkeynes@998:         /* Command unsupported */
nkeynes@998:         WARN( "Received unknown GDB command '%c%s'", command, data ); 
nkeynes@998:         gdb_send_frame( server, "", 0 );
nkeynes@998:         break;
nkeynes@998:     }
nkeynes@998: 
nkeynes@998: }
nkeynes@998: 
nkeynes@998: /**
nkeynes@998:  * Decode out frames from the raw data stream. A frame takes the form of
nkeynes@998:  *   $<data>#<checksum>
nkeynes@998:  * where data may not contain a '#' character, and checksum is a simple 
nkeynes@998:  * 8-bit modulo sum of all bytes in data, encoded as a 2-char hex number.
nkeynes@998:  * 
nkeynes@998:  * The only other legal wire forms are 
nkeynes@998:  *   + 
nkeynes@998:  * indicating successful reception of the last message (ignored here), and
nkeynes@998:  *   -
nkeynes@998:  * indicating failed reception of the last message - need to resend.
nkeynes@998:  */
nkeynes@998: void gdb_server_process_buffer( struct gdb_server *server )
nkeynes@998: {
nkeynes@998:     int i, frame_start = -1, frame_len = -1;
nkeynes@998:     for( i=0; i<server->buf_posn; i++ ) {
nkeynes@998:         if( frame_start == -1 ) {
nkeynes@998:             if( server->buf[i] == '$' ) {
nkeynes@998:                 frame_start = i;
nkeynes@998:             } else if( server->buf[i] == '+' ) {
nkeynes@998:                 /* Success */
nkeynes@998:                 continue;
nkeynes@998:             } else if( server->buf[i] == '-' ) {
nkeynes@998:                 /* Request retransmit */
nkeynes@998:             } /* Anything else is noise */
nkeynes@998:         } else if( server->buf[i] == '#' ) {
nkeynes@998:             frame_len = i - frame_start - 1;
nkeynes@998:             if( i+2 < server->buf_posn ) {
nkeynes@998:                 int calc_checksum = gdb_checksum( &server->buf[frame_start+1], frame_len );
nkeynes@998:                 int frame_checksum = 0;
nkeynes@998:                 sscanf( &server->buf[i+1], "%02x", &frame_checksum );    
nkeynes@998: 
nkeynes@998:                 if( calc_checksum != frame_checksum ) {
nkeynes@998:                     WARN( "GDB frame checksum failure (expected %02X but was %02X)", 
nkeynes@998:                             calc_checksum, frame_checksum ); 
nkeynes@998:                     write( server->fd, "-", 1 );
nkeynes@998:                 } else if( frame_len == 0 ) {
nkeynes@998:                     /* Empty frame - should never occur as a request */
nkeynes@998:                     WARN( "Empty GDB frame received" );
nkeynes@998:                     write( server->fd, "-", 1 );
nkeynes@998:                 } else {
nkeynes@998:                     /* We have a good frame */
nkeynes@998:                     write( server->fd, "+", 1 );
nkeynes@998:                     server->buf[i] = '\0';
nkeynes@998:                     gdb_server_handle_frame( server, server->buf[frame_start+1], &server->buf[frame_start+2], frame_len-1 );
nkeynes@998:                 }
nkeynes@998:                 i+=2;
nkeynes@998:                 frame_start = -1;
nkeynes@998:             }
nkeynes@998:         }
nkeynes@998:     }
nkeynes@998:     if( frame_start == -1 ) {
nkeynes@998:         server->buf_posn = 0; /* Consumed whole buffer */
nkeynes@998:     } else if( frame_start > 0 ) {
nkeynes@998:         memmove(&server->buf[0], &server->buf[frame_start], server->buf_posn - frame_start);
nkeynes@998:         server->buf_posn -= frame_start;
nkeynes@998:     }
nkeynes@998: }
nkeynes@998: 
nkeynes@998: gboolean gdb_server_data_callback( int fd, void *data )
nkeynes@998: {
nkeynes@998:     struct gdb_server *server = (struct gdb_server *)data;
nkeynes@998: 
nkeynes@998:     size_t len = read( fd, &server->buf[server->buf_posn], server->buf_size - server->buf_posn );
nkeynes@998:     if( len > 0 ) {
nkeynes@998:         server->buf_posn += len;
nkeynes@998:         gdb_server_process_buffer( server );
nkeynes@998: 
nkeynes@998:         /* If we have an oversized packet, extend the buffer */
nkeynes@998:         if( server->buf_posn > server->buf_size - BUFFER_SIZE_MARGIN &&
nkeynes@998:                 server->buf_size < MAX_BUFFER_SIZE ) {
nkeynes@998:             server->buf_size <<= 1;
nkeynes@998:             server->buf = realloc( server->buf, server->buf_size );
nkeynes@998:             assert( server->buf != NULL );
nkeynes@998:         }
nkeynes@998:         return TRUE;
nkeynes@998:     } else {
nkeynes@998:         INFO( "GDB disconnected" );
nkeynes@998:         return FALSE;
nkeynes@998:     }
nkeynes@998: }
nkeynes@998: 
nkeynes@998: gboolean gdb_server_connect_callback( int fd, gpointer data )
nkeynes@998: {
nkeynes@998:     struct sockaddr_in sin;
nkeynes@998:     socklen_t sinlen;
nkeynes@998:     struct gdb_server *server = (struct gdb_server *)data;
nkeynes@998:     int conn_fd = accept( fd, (struct sockaddr *)&sin, &sinlen);
nkeynes@998:     if( conn_fd != -1 ) {
nkeynes@998:         struct gdb_server *chan_serv = calloc( sizeof(struct gdb_server), 1 );
nkeynes@998:         chan_serv->cpu = server->cpu;
nkeynes@998:         chan_serv->mmu = server->mmu;
nkeynes@998:         chan_serv->fd = conn_fd;
nkeynes@998:         chan_serv->peer_name = g_strdup_printf("%s:%d", inet_ntoa(sin.sin_addr), ntohs(sin.sin_port)); 
nkeynes@998:         chan_serv->buf = malloc(1024);
nkeynes@998:         chan_serv->buf_size = 1024;
nkeynes@998:         chan_serv->buf_posn = 0;
nkeynes@1077:         io_register_tcp_listener( conn_fd, gdb_server_data_callback, chan_serv, gdb_server_free );
nkeynes@998:         INFO( "GDB connected from %s", chan_serv->peer_name );
nkeynes@998:     }
nkeynes@998:     return TRUE;
nkeynes@998: }
nkeynes@998: 
nkeynes@998: /**
nkeynes@998:  * Bind a network port for a GDB remote server for the specified cpu. The
nkeynes@998:  * port is registered for the system network callback.
nkeynes@998:  * 
nkeynes@998:  * @param interface network interface to bind to, or null for the default (all) interface  
nkeynes@998:  * @param port 
nkeynes@998:  * @param cpu CPU to make available over the network port.. 
nkeynes@998:  * @param mmu if TRUE, virtual memory is made available to GDB, otherwise GDB
nkeynes@998:  *     accesses physical memory.
nkeynes@998:  * @return TRUE if the server was bound successfully.
nkeynes@998:  */
nkeynes@998: gboolean gdb_init_server( const char *interface, int port, cpu_desc_t cpu, gboolean mmu )
nkeynes@998: {
nkeynes@1077:     int fd = io_create_server_socket( interface, port );
nkeynes@998:     if( fd == -1 ) {
nkeynes@998:         return FALSE;
nkeynes@998:     }
nkeynes@998: 
nkeynes@998:     struct gdb_server *server = calloc( sizeof(struct gdb_server), 1 );
nkeynes@998:     server->cpu = cpu;
nkeynes@998:     server->mmu = mmu;
nkeynes@998:     server->fd = fd;
nkeynes@1081:     gboolean result = io_register_tcp_listener( fd, gdb_server_connect_callback, server, gdb_server_free ) != NULL;
nkeynes@1071:     INFO( "%s GDB server running on port %d", cpu->name, port );
nkeynes@1071:     return result;
nkeynes@998: }