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author | marcel <marcel@FreeBSD.org> | 2004-07-10 17:47:22 +0000 |
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committer | marcel <marcel@FreeBSD.org> | 2004-07-10 17:47:22 +0000 |
commit | 6e0dcca8a9676834e327681abedbeca81a0907f2 (patch) | |
tree | 787a3c6916bdd82a49a07a8288119d62dd89055b /sys/gdb/gdb_packet.c | |
parent | 1ff719505763720315217ca8b7eb6d6f03c49222 (diff) | |
download | FreeBSD-src-6e0dcca8a9676834e327681abedbeca81a0907f2.zip FreeBSD-src-6e0dcca8a9676834e327681abedbeca81a0907f2.tar.gz |
Introduce the GDB debugger backend for the new KDB framework. The
backend improves over the old GDB support in the following ways:
o Unified implementation with minimal MD code.
o A simple interface for devices to register themselves as debug
ports, ala consoles.
o Compression by using run-length encoding.
o Implements GDB threading support.
Diffstat (limited to 'sys/gdb/gdb_packet.c')
-rw-r--r-- | sys/gdb/gdb_packet.c | 289 |
1 files changed, 289 insertions, 0 deletions
diff --git a/sys/gdb/gdb_packet.c b/sys/gdb/gdb_packet.c new file mode 100644 index 0000000..703d2e0 --- /dev/null +++ b/sys/gdb/gdb_packet.c @@ -0,0 +1,289 @@ +/* + * 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 <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) + +/* + * 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_cur->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_cur->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_cur->gdb_getc(); + cksum -= (C2N(c) << 4) & 0xf0; + c = gdb_cur->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) +{ + void *prev; + jmp_buf jb; + int ret; + unsigned char c; + + if (size * 2 != gdb_rxsz) + return (-1); + + prev = kdb_jmpbuf(jb); + ret = setjmp(jb); + if (ret == 0) { + while (size-- > 0) { + c = (C2N(gdb_rxp[0]) << 4) & 0xf0; + c |= C2N(gdb_rxp[1]) & 0x0f; + *addr++ = c; + gdb_rxsz -= 2; + gdb_rxp += 2; + } + } + (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_cur->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, ®sz); + if (regp == NULL) { + /* Register unavailable. */ + while (regsz--) { + gdb_tx_char('x'); + gdb_tx_char('x'); + } + } else + gdb_tx_mem(regp, regsz); +} |