diff options
Diffstat (limited to 'gpxe/src/core/gdbstub.c')
| -rw-r--r-- | gpxe/src/core/gdbstub.c | 397 |
1 files changed, 0 insertions, 397 deletions
diff --git a/gpxe/src/core/gdbstub.c b/gpxe/src/core/gdbstub.c deleted file mode 100644 index c8083955..00000000 --- a/gpxe/src/core/gdbstub.c +++ /dev/null @@ -1,397 +0,0 @@ -/* - * Copyright (C) 2008 Stefan Hajnoczi <stefanha@gmail.com>. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License as - * published by the Free Software Foundation; either version 2 of the - * License, or any later version. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - */ - -/** - * @file - * - * GDB stub for remote debugging - * - */ - -#include <stdlib.h> -#include <stdio.h> -#include <string.h> -#include <ctype.h> -#include <byteswap.h> -#include <gpxe/gdbstub.h> -#include "gdbmach.h" - -enum { - POSIX_EINVAL = 0x1c, /* used to report bad arguments to GDB */ - SIZEOF_PAYLOAD = 256, /* buffer size of GDB payload data */ -}; - -struct gdbstub { - struct gdb_transport *trans; - int exit_handler; /* leave interrupt handler */ - - int signo; - gdbreg_t *regs; - - void ( * parse ) ( struct gdbstub *stub, char ch ); - uint8_t cksum1; - - /* Buffer for payload data when parsing a packet. Once the - * packet has been received, this buffer is used to hold - * the reply payload. */ - char buf [ SIZEOF_PAYLOAD + 4 ]; /* $...PAYLOAD...#XX */ - char *payload; /* start of payload */ - int len; /* length of payload */ -}; - -/* Packet parser states */ -static void gdbstub_state_new ( struct gdbstub *stub, char ch ); -static void gdbstub_state_data ( struct gdbstub *stub, char ch ); -static void gdbstub_state_cksum1 ( struct gdbstub *stub, char ch ); -static void gdbstub_state_cksum2 ( struct gdbstub *stub, char ch ); -static void gdbstub_state_wait_ack ( struct gdbstub *stub, char ch ); - -static uint8_t gdbstub_from_hex_digit ( char ch ) { - return ( isdigit ( ch ) ? ch - '0' : tolower ( ch ) - 'a' + 0xa ) & 0xf; -} - -static uint8_t gdbstub_to_hex_digit ( uint8_t b ) { - b &= 0xf; - return ( b < 0xa ? '0' : 'a' - 0xa ) + b; -} - -/* - * To make reading/writing device memory atomic, we check for - * 2- or 4-byte aligned operations and handle them specially. - */ - -static void gdbstub_from_hex_buf ( char *dst, char *src, int lenbytes ) { - if ( lenbytes == 2 && ( ( unsigned long ) dst & 0x1 ) == 0 ) { - uint16_t i = gdbstub_from_hex_digit ( src [ 2 ] ) << 12 | - gdbstub_from_hex_digit ( src [ 3 ] ) << 8 | - gdbstub_from_hex_digit ( src [ 0 ] ) << 4 | - gdbstub_from_hex_digit ( src [ 1 ] ); - * ( uint16_t * ) dst = cpu_to_le16 ( i ); - } else if ( lenbytes == 4 && ( ( unsigned long ) dst & 0x3 ) == 0 ) { - uint32_t i = gdbstub_from_hex_digit ( src [ 6 ] ) << 28 | - gdbstub_from_hex_digit ( src [ 7 ] ) << 24 | - gdbstub_from_hex_digit ( src [ 4 ] ) << 20 | - gdbstub_from_hex_digit ( src [ 5 ] ) << 16 | - gdbstub_from_hex_digit ( src [ 2 ] ) << 12 | - gdbstub_from_hex_digit ( src [ 3 ] ) << 8 | - gdbstub_from_hex_digit ( src [ 0 ] ) << 4 | - gdbstub_from_hex_digit ( src [ 1 ] ); - * ( uint32_t * ) dst = cpu_to_le32 ( i ); - } else { - while ( lenbytes-- > 0 ) { - *dst++ = gdbstub_from_hex_digit ( src [ 0 ] ) << 4 | - gdbstub_from_hex_digit ( src [ 1 ] ); - src += 2; - } - } -} - -static void gdbstub_to_hex_buf ( char *dst, char *src, int lenbytes ) { - if ( lenbytes == 2 && ( ( unsigned long ) src & 0x1 ) == 0 ) { - uint16_t i = cpu_to_le16 ( * ( uint16_t * ) src ); - dst [ 0 ] = gdbstub_to_hex_digit ( i >> 4 ); - dst [ 1 ] = gdbstub_to_hex_digit ( i ); - dst [ 2 ] = gdbstub_to_hex_digit ( i >> 12 ); - dst [ 3 ] = gdbstub_to_hex_digit ( i >> 8 ); - } else if ( lenbytes == 4 && ( ( unsigned long ) src & 0x3 ) == 0 ) { - uint32_t i = cpu_to_le32 ( * ( uint32_t * ) src ); - dst [ 0 ] = gdbstub_to_hex_digit ( i >> 4 ); - dst [ 1 ] = gdbstub_to_hex_digit ( i ); - dst [ 2 ] = gdbstub_to_hex_digit ( i >> 12 ); - dst [ 3 ] = gdbstub_to_hex_digit ( i >> 8 ); - dst [ 4 ] = gdbstub_to_hex_digit ( i >> 20 ); - dst [ 5 ] = gdbstub_to_hex_digit ( i >> 16); - dst [ 6 ] = gdbstub_to_hex_digit ( i >> 28 ); - dst [ 7 ] = gdbstub_to_hex_digit ( i >> 24 ); - } else { - while ( lenbytes-- > 0 ) { - *dst++ = gdbstub_to_hex_digit ( *src >> 4 ); - *dst++ = gdbstub_to_hex_digit ( *src ); - src++; - } - } -} - -static uint8_t gdbstub_cksum ( char *data, int len ) { - uint8_t cksum = 0; - while ( len-- > 0 ) { - cksum += ( uint8_t ) *data++; - } - return cksum; -} - -static void gdbstub_tx_packet ( struct gdbstub *stub ) { - uint8_t cksum = gdbstub_cksum ( stub->payload, stub->len ); - stub->buf [ 0 ] = '$'; - stub->buf [ stub->len + 1 ] = '#'; - stub->buf [ stub->len + 2 ] = gdbstub_to_hex_digit ( cksum >> 4 ); - stub->buf [ stub->len + 3 ] = gdbstub_to_hex_digit ( cksum ); - stub->trans->send ( stub->buf, stub->len + 4 ); - stub->parse = gdbstub_state_wait_ack; -} - -/* GDB commands */ -static void gdbstub_send_ok ( struct gdbstub *stub ) { - stub->payload [ 0 ] = 'O'; - stub->payload [ 1 ] = 'K'; - stub->len = 2; - gdbstub_tx_packet ( stub ); -} - -static void gdbstub_send_num_packet ( struct gdbstub *stub, char reply, int num ) { - stub->payload [ 0 ] = reply; - stub->payload [ 1 ] = gdbstub_to_hex_digit ( ( char ) num >> 4 ); - stub->payload [ 2 ] = gdbstub_to_hex_digit ( ( char ) num ); - stub->len = 3; - gdbstub_tx_packet ( stub ); -} - -/* Format is arg1,arg2,...,argn:data where argn are hex integers and data is not an argument */ -static int gdbstub_get_packet_args ( struct gdbstub *stub, unsigned long *args, int nargs, int *stop_idx ) { - int i; - char ch = 0; - int argc = 0; - unsigned long val = 0; - for ( i = 1; i < stub->len && argc < nargs; i++ ) { - ch = stub->payload [ i ]; - if ( ch == ':' ) { - break; - } else if ( ch == ',' ) { - args [ argc++ ] = val; - val = 0; - } else { - val = ( val << 4 ) | gdbstub_from_hex_digit ( ch ); - } - } - if ( stop_idx ) { - *stop_idx = i; - } - if ( argc < nargs ) { - args [ argc++ ] = val; - } - return ( ( i == stub->len || ch == ':' ) && argc == nargs ); -} - -static void gdbstub_send_errno ( struct gdbstub *stub, int errno ) { - gdbstub_send_num_packet ( stub, 'E', errno ); -} - -static void gdbstub_report_signal ( struct gdbstub *stub ) { - gdbstub_send_num_packet ( stub, 'S', stub->signo ); -} - -static void gdbstub_read_regs ( struct gdbstub *stub ) { - gdbstub_to_hex_buf ( stub->payload, ( char * ) stub->regs, GDBMACH_SIZEOF_REGS ); - stub->len = GDBMACH_SIZEOF_REGS * 2; - gdbstub_tx_packet ( stub ); -} - -static void gdbstub_write_regs ( struct gdbstub *stub ) { - if ( stub->len != 1 + GDBMACH_SIZEOF_REGS * 2 ) { - gdbstub_send_errno ( stub, POSIX_EINVAL ); - return; - } - gdbstub_from_hex_buf ( ( char * ) stub->regs, &stub->payload [ 1 ], GDBMACH_SIZEOF_REGS ); - gdbstub_send_ok ( stub ); -} - -static void gdbstub_read_mem ( struct gdbstub *stub ) { - unsigned long args [ 2 ]; - if ( !gdbstub_get_packet_args ( stub, args, sizeof args / sizeof args [ 0 ], NULL ) ) { - gdbstub_send_errno ( stub, POSIX_EINVAL ); - return; - } - args [ 1 ] = ( args [ 1 ] < SIZEOF_PAYLOAD / 2 ) ? args [ 1 ] : SIZEOF_PAYLOAD / 2; - gdbstub_to_hex_buf ( stub->payload, ( char * ) args [ 0 ], args [ 1 ] ); - stub->len = args [ 1 ] * 2; - gdbstub_tx_packet ( stub ); -} - -static void gdbstub_write_mem ( struct gdbstub *stub ) { - unsigned long args [ 2 ]; - int colon; - if ( !gdbstub_get_packet_args ( stub, args, sizeof args / sizeof args [ 0 ], &colon ) || - colon >= stub->len || stub->payload [ colon ] != ':' || - ( stub->len - colon - 1 ) % 2 != 0 ) { - gdbstub_send_errno ( stub, POSIX_EINVAL ); - return; - } - gdbstub_from_hex_buf ( ( char * ) args [ 0 ], &stub->payload [ colon + 1 ], ( stub->len - colon - 1 ) / 2 ); - gdbstub_send_ok ( stub ); -} - -static void gdbstub_continue ( struct gdbstub *stub, int single_step ) { - gdbreg_t pc; - if ( stub->len > 1 && gdbstub_get_packet_args ( stub, &pc, 1, NULL ) ) { - gdbmach_set_pc ( stub->regs, pc ); - } - gdbmach_set_single_step ( stub->regs, single_step ); - stub->exit_handler = 1; - /* Reply will be sent when we hit the next breakpoint or interrupt */ -} - -static void gdbstub_breakpoint ( struct gdbstub *stub ) { - unsigned long args [ 3 ]; - int enable = stub->payload [ 0 ] == 'Z' ? 1 : 0; - if ( !gdbstub_get_packet_args ( stub, args, sizeof args / sizeof args [ 0 ], NULL ) ) { - gdbstub_send_errno ( stub, POSIX_EINVAL ); - return; - } - if ( gdbmach_set_breakpoint ( args [ 0 ], args [ 1 ], args [ 2 ], enable ) ) { - gdbstub_send_ok ( stub ); - } else { - /* Not supported */ - stub->len = 0; - gdbstub_tx_packet ( stub ); - } -} - -static void gdbstub_rx_packet ( struct gdbstub *stub ) { - switch ( stub->payload [ 0 ] ) { - case '?': - gdbstub_report_signal ( stub ); - break; - case 'g': - gdbstub_read_regs ( stub ); - break; - case 'G': - gdbstub_write_regs ( stub ); - break; - case 'm': - gdbstub_read_mem ( stub ); - break; - case 'M': - gdbstub_write_mem ( stub ); - break; - case 'c': /* Continue */ - case 'k': /* Kill */ - case 's': /* Step */ - case 'D': /* Detach */ - gdbstub_continue ( stub, stub->payload [ 0 ] == 's' ); - if ( stub->payload [ 0 ] == 'D' ) { - gdbstub_send_ok ( stub ); - } - break; - case 'Z': /* Insert breakpoint */ - case 'z': /* Remove breakpoint */ - gdbstub_breakpoint ( stub ); - break; - default: - stub->len = 0; - gdbstub_tx_packet ( stub ); - break; - } -} - -/* GDB packet parser */ -static void gdbstub_state_new ( struct gdbstub *stub, char ch ) { - if ( ch == '$' ) { - stub->len = 0; - stub->parse = gdbstub_state_data; - } -} - -static void gdbstub_state_data ( struct gdbstub *stub, char ch ) { - if ( ch == '#' ) { - stub->parse = gdbstub_state_cksum1; - } else if ( ch == '$' ) { - stub->len = 0; /* retry new packet */ - } else { - /* If the length exceeds our buffer, let the checksum fail */ - if ( stub->len < SIZEOF_PAYLOAD ) { - stub->payload [ stub->len++ ] = ch; - } - } -} - -static void gdbstub_state_cksum1 ( struct gdbstub *stub, char ch ) { - stub->cksum1 = gdbstub_from_hex_digit ( ch ) << 4; - stub->parse = gdbstub_state_cksum2; -} - -static void gdbstub_state_cksum2 ( struct gdbstub *stub, char ch ) { - uint8_t their_cksum; - uint8_t our_cksum; - - stub->parse = gdbstub_state_new; - their_cksum = stub->cksum1 + gdbstub_from_hex_digit ( ch ); - our_cksum = gdbstub_cksum ( stub->payload, stub->len ); - if ( their_cksum == our_cksum ) { - stub->trans->send ( "+", 1 ); - if ( stub->len > 0 ) { - gdbstub_rx_packet ( stub ); - } - } else { - stub->trans->send ( "-", 1 ); - } -} - -static void gdbstub_state_wait_ack ( struct gdbstub *stub, char ch ) { - if ( ch == '+' ) { - stub->parse = gdbstub_state_new; - } else { - /* This retransmit is very aggressive but necessary to keep - * in sync with GDB. */ - gdbstub_tx_packet ( stub ); - } -} - -static void gdbstub_parse ( struct gdbstub *stub, char ch ) { - stub->parse ( stub, ch ); -} - -static struct gdbstub stub = { - .parse = gdbstub_state_new -}; - -void gdbstub_handler ( int signo, gdbreg_t *regs ) { - char packet [ SIZEOF_PAYLOAD + 4 ]; - size_t len, i; - - /* A transport must be set up */ - if ( !stub.trans ) { - return; - } - - stub.signo = signo; - stub.regs = regs; - stub.exit_handler = 0; - gdbstub_report_signal ( &stub ); - while ( !stub.exit_handler && ( len = stub.trans->recv ( packet, sizeof ( packet ) ) ) > 0 ) { - for ( i = 0; i < len; i++ ) { - gdbstub_parse ( &stub, packet [ i ] ); - } - } -} - -struct gdb_transport *find_gdb_transport ( const char *name ) { - struct gdb_transport *trans; - - for_each_table_entry ( trans, GDB_TRANSPORTS ) { - if ( strcmp ( trans->name, name ) == 0 ) { - return trans; - } - } - return NULL; -} - -void gdbstub_start ( struct gdb_transport *trans ) { - stub.trans = trans; - stub.payload = &stub.buf [ 1 ]; - gdbmach_breakpoint(); -} |