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freebsd/sys/gdb/gdb_packet.c
Marcel Moolenaar 01bd17cc99 Add kdb_cpu_sync_icache(), intended to synchronize instruction
caches with data caches after writing to memory. This typically
is required to make breakpoints work on ia64 and powerpc. For
those architectures the function is implemented.
2007-06-09 21:55:17 +00:00

311 lines
6.0 KiB
C

/*-
* Copyright (c) 2004 Marcel Moolenaar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ctype.h>
#include <sys/kdb.h>
#include <machine/gdb_machdep.h>
#include <machine/kdb.h>
#include <gdb/gdb.h>
#include <gdb/gdb_int.h>
static char gdb_rxbuf[GDB_BUFSZ];
char *gdb_rxp = NULL;
size_t gdb_rxsz = 0;
static char gdb_txbuf[GDB_BUFSZ];
char *gdb_txp = NULL; /* Used in inline functions. */
#define C2N(c) (((c) < 'A') ? (c) - '0' : \
10 + (((c) < 'a') ? (c) - 'A' : (c) - 'a'))
#define N2C(n) (((n) < 10) ? (n) + '0' : (n) + 'a' - 10)
/*
* Get a single character
*/
static int
gdb_getc(void)
{
int c;
do
c = gdb_cur->gdb_getc();
while (c == -1);
return (c);
}
/*
* Functions to receive and extract from a packet.
*/
int
gdb_rx_begin(void)
{
int c, cksum;
gdb_rxp = NULL;
do {
/*
* Wait for the start character, ignore all others.
* XXX needs a timeout.
*/
while ((c = gdb_getc()) != '$')
;
/* Read until a # or end of buffer is found. */
cksum = 0;
gdb_rxsz = 0;
while (gdb_rxsz < sizeof(gdb_rxbuf) - 1) {
c = gdb_getc();
if (c == '#')
break;
gdb_rxbuf[gdb_rxsz++] = c;
cksum += c;
}
gdb_rxbuf[gdb_rxsz] = 0;
cksum &= 0xff;
/* Bail out on a buffer overflow. */
if (c != '#') {
gdb_cur->gdb_putc('-');
return (ENOSPC);
}
c = gdb_getc();
cksum -= (C2N(c) << 4) & 0xf0;
c = gdb_getc();
cksum -= C2N(c) & 0x0f;
gdb_cur->gdb_putc((cksum == 0) ? '+' : '-');
if (cksum != 0)
printf("GDB: packet `%s' has invalid checksum\n",
gdb_rxbuf);
} while (cksum != 0);
gdb_rxp = gdb_rxbuf;
return (0);
}
int
gdb_rx_equal(const char *str)
{
int len;
len = strlen(str);
if (len > gdb_rxsz || strncmp(str, gdb_rxp, len) != 0)
return (0);
gdb_rxp += len;
gdb_rxsz -= len;
return (1);
}
int
gdb_rx_mem(unsigned char *addr, size_t size)
{
unsigned char *p;
void *prev;
jmp_buf jb;
size_t cnt;
int ret;
unsigned char c;
if (size * 2 != gdb_rxsz)
return (-1);
prev = kdb_jmpbuf(jb);
ret = setjmp(jb);
if (ret == 0) {
p = addr;
cnt = size;
while (cnt-- > 0) {
c = (C2N(gdb_rxp[0]) << 4) & 0xf0;
c |= C2N(gdb_rxp[1]) & 0x0f;
*p++ = c;
gdb_rxsz -= 2;
gdb_rxp += 2;
}
kdb_cpu_sync_icache(addr, size);
}
(void)kdb_jmpbuf(prev);
return ((ret == 0) ? 1 : 0);
}
int
gdb_rx_varhex(uintmax_t *vp)
{
uintmax_t v;
int c, neg;
c = gdb_rx_char();
neg = (c == '-') ? 1 : 0;
if (neg == 1)
c = gdb_rx_char();
if (!isxdigit(c)) {
gdb_rxp -= ((c == -1) ? 0 : 1) + neg;
gdb_rxsz += ((c == -1) ? 0 : 1) + neg;
return (-1);
}
v = 0;
do {
v <<= 4;
v += C2N(c);
c = gdb_rx_char();
} while (isxdigit(c));
if (c != -1) {
gdb_rxp--;
gdb_rxsz++;
}
*vp = (neg) ? -v : v;
return (0);
}
/*
* Function to build and send a package.
*/
void
gdb_tx_begin(char tp)
{
gdb_txp = gdb_txbuf;
if (tp != '\0')
gdb_tx_char(tp);
}
int
gdb_tx_end(void)
{
const char *p;
int runlen;
unsigned char c, cksum;
do {
gdb_cur->gdb_putc('$');
cksum = 0;
p = gdb_txbuf;
while (p < gdb_txp) {
/* Send a character and start run-length encoding. */
c = *p++;
gdb_cur->gdb_putc(c);
cksum += c;
runlen = 0;
/* Determine run-length and update checksum. */
while (p < gdb_txp && *p == c) {
runlen++;
p++;
}
/* Emit the run-length encoded string. */
while (runlen >= 97) {
gdb_cur->gdb_putc('*');
cksum += '*';
gdb_cur->gdb_putc(97+29);
cksum += 97+29;
runlen -= 97;
if (runlen > 0) {
gdb_cur->gdb_putc(c);
cksum += c;
runlen--;
}
}
if (runlen == 1) {
gdb_cur->gdb_putc(c);
cksum += c;
runlen--;
}
if (runlen == 0)
continue;
/* Don't emit '$', '#', '+' or '-'. */
if (runlen == 7) {
gdb_cur->gdb_putc(c);
cksum += c;
runlen--;
}
if (runlen == 6 || runlen == 14 || runlen == 16) {
gdb_cur->gdb_putc(c);
cksum += c;
runlen--;
}
gdb_cur->gdb_putc('*');
cksum += '*';
gdb_cur->gdb_putc(runlen+29);
cksum += runlen+29;
}
gdb_cur->gdb_putc('#');
c = cksum >> 4;
gdb_cur->gdb_putc(N2C(c));
c = cksum & 0x0f;
gdb_cur->gdb_putc(N2C(c));
c = gdb_getc();
} while (c != '+');
return (0);
}
int
gdb_tx_mem(const unsigned char *addr, size_t size)
{
void *prev;
jmp_buf jb;
int ret;
prev = kdb_jmpbuf(jb);
ret = setjmp(jb);
if (ret == 0) {
while (size-- > 0) {
*gdb_txp++ = N2C(*addr >> 4);
*gdb_txp++ = N2C(*addr & 0x0f);
addr++;
}
}
(void)kdb_jmpbuf(prev);
return ((ret == 0) ? 1 : 0);
}
void
gdb_tx_reg(int regnum)
{
unsigned char *regp;
size_t regsz;
regp = gdb_cpu_getreg(regnum, &regsz);
if (regp == NULL) {
/* Register unavailable. */
while (regsz--) {
gdb_tx_char('x');
gdb_tx_char('x');
}
} else
gdb_tx_mem(regp, regsz);
}