xref: /freebsd/sys/gdb/gdb_cons.c (revision af3b2549c4ba2ef00a7cbb4cb6836598bf0aefbe)
17d0c6c9fSSam Leffler /*-
27d0c6c9fSSam Leffler  * Copyright (c) 2006 Sam Leffler
37d0c6c9fSSam Leffler  * All rights reserved.
47d0c6c9fSSam Leffler  *
57d0c6c9fSSam Leffler  * Redistribution and use in source and binary forms, with or without
67d0c6c9fSSam Leffler  * modification, are permitted provided that the following conditions
77d0c6c9fSSam Leffler  * are met:
87d0c6c9fSSam Leffler  *
97d0c6c9fSSam Leffler  * 1. Redistributions of source code must retain the above copyright
107d0c6c9fSSam Leffler  *    notice, this list of conditions and the following disclaimer.
117d0c6c9fSSam Leffler  * 2. Redistributions in binary form must reproduce the above copyright
127d0c6c9fSSam Leffler  *    notice, this list of conditions and the following disclaimer in the
137d0c6c9fSSam Leffler  *    documentation and/or other materials provided with the distribution.
147d0c6c9fSSam Leffler  *
157d0c6c9fSSam Leffler  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
167d0c6c9fSSam Leffler  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
177d0c6c9fSSam Leffler  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
187d0c6c9fSSam Leffler  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
197d0c6c9fSSam Leffler  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
207d0c6c9fSSam Leffler  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
217d0c6c9fSSam Leffler  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
227d0c6c9fSSam Leffler  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
237d0c6c9fSSam Leffler  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
247d0c6c9fSSam Leffler  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
257d0c6c9fSSam Leffler  */
267d0c6c9fSSam Leffler 
277d0c6c9fSSam Leffler /*
287d0c6c9fSSam Leffler  * Support for redirecting console msgs to gdb.  We register
297d0c6c9fSSam Leffler  * a pseudo console to hook cnputc and send stuff to the gdb
307d0c6c9fSSam Leffler  * port.  The only trickiness here is buffering output so this
317d0c6c9fSSam Leffler  * isn't dog slow.
327d0c6c9fSSam Leffler  */
337d0c6c9fSSam Leffler 
347d0c6c9fSSam Leffler #include <sys/cdefs.h>
357d0c6c9fSSam Leffler __FBSDID("$FreeBSD$");
367d0c6c9fSSam Leffler 
377d0c6c9fSSam Leffler #include <sys/param.h>
387d0c6c9fSSam Leffler #include <sys/systm.h>
397d0c6c9fSSam Leffler #include <sys/cons.h>
407d0c6c9fSSam Leffler #include <sys/kdb.h>
417d0c6c9fSSam Leffler #include <sys/kernel.h>
427d0c6c9fSSam Leffler #include <sys/malloc.h>
437d0c6c9fSSam Leffler #include <sys/reboot.h>
447d0c6c9fSSam Leffler #include <sys/sysctl.h>
457d0c6c9fSSam Leffler 
467d0c6c9fSSam Leffler #include <machine/gdb_machdep.h>
477d0c6c9fSSam Leffler #include <machine/kdb.h>
487d0c6c9fSSam Leffler 
497d0c6c9fSSam Leffler #include <gdb/gdb.h>
507d0c6c9fSSam Leffler #include <gdb/gdb_int.h>
517d0c6c9fSSam Leffler 
527d0c6c9fSSam Leffler struct gdbcons {
537d0c6c9fSSam Leffler 	int	npending;
547d0c6c9fSSam Leffler 	/* /2 for hex conversion, -6 for protocol glue */
557d0c6c9fSSam Leffler 	char	buf[GDB_BUFSZ/2 - 6];
567d0c6c9fSSam Leffler 	struct callout flush;
577d0c6c9fSSam Leffler };
587d0c6c9fSSam Leffler static struct gdbcons state = { -1 };
597d0c6c9fSSam Leffler 
607d0c6c9fSSam Leffler static	int gdbcons_enable = 0;
61*af3b2549SHans Petter Selasky SYSCTL_INT(_debug, OID_AUTO, gdbcons, CTLFLAG_RWTUN, &gdbcons_enable,
62*af3b2549SHans Petter Selasky 	    0, "copy console messages to GDB");
637d0c6c9fSSam Leffler 
647d0c6c9fSSam Leffler static void
657d0c6c9fSSam Leffler gdb_cnprobe(struct consdev *cp)
667d0c6c9fSSam Leffler {
677d0c6c9fSSam Leffler 	sprintf(cp->cn_name, "gdb");
687d0c6c9fSSam Leffler 	cp->cn_pri = CN_LOW;		/* XXX no way to say "write only" */
697d0c6c9fSSam Leffler }
707d0c6c9fSSam Leffler 
717d0c6c9fSSam Leffler static void
727d0c6c9fSSam Leffler gdb_cninit(struct consdev *cp)
737d0c6c9fSSam Leffler {
747d0c6c9fSSam Leffler 	struct gdbcons *c = &state;
757d0c6c9fSSam Leffler 
767d0c6c9fSSam Leffler 	/* setup tx buffer and callout */
777d0c6c9fSSam Leffler 	if (c->npending == -1) {
787d0c6c9fSSam Leffler 		c->npending = 0;
797d0c6c9fSSam Leffler 		callout_init(&c->flush, CALLOUT_MPSAFE);
807d0c6c9fSSam Leffler 		cp->cn_arg = c;
817d0c6c9fSSam Leffler 	}
827d0c6c9fSSam Leffler }
837d0c6c9fSSam Leffler 
847672c959SPoul-Henning Kamp static void
857672c959SPoul-Henning Kamp gdb_cnterm(struct consdev *cp)
867672c959SPoul-Henning Kamp {
877672c959SPoul-Henning Kamp }
887672c959SPoul-Henning Kamp 
899976156fSAndriy Gapon static void
909976156fSAndriy Gapon gdb_cngrab(struct consdev *cp)
919976156fSAndriy Gapon {
929976156fSAndriy Gapon }
939976156fSAndriy Gapon 
949976156fSAndriy Gapon static void
959976156fSAndriy Gapon gdb_cnungrab(struct consdev *cp)
969976156fSAndriy Gapon {
979976156fSAndriy Gapon }
989976156fSAndriy Gapon 
997d0c6c9fSSam Leffler static int
1007672c959SPoul-Henning Kamp gdb_cngetc(struct consdev *cp)
1017d0c6c9fSSam Leffler {
1027d0c6c9fSSam Leffler 	return -1;
1037d0c6c9fSSam Leffler }
1047d0c6c9fSSam Leffler 
1057d0c6c9fSSam Leffler static void
1067d0c6c9fSSam Leffler gdb_tx_puthex(int c)
1077d0c6c9fSSam Leffler {
1087d0c6c9fSSam Leffler 	const char *hex = "0123456789abcdef";
1097d0c6c9fSSam Leffler 
1107d0c6c9fSSam Leffler 	gdb_tx_char(hex[(c>>4)&0xf]);
1117d0c6c9fSSam Leffler 	gdb_tx_char(hex[(c>>0)&0xf]);
1127d0c6c9fSSam Leffler }
1137d0c6c9fSSam Leffler 
1147d0c6c9fSSam Leffler static void
1157d0c6c9fSSam Leffler gdb_cnflush(void *arg)
1167d0c6c9fSSam Leffler {
1177d0c6c9fSSam Leffler 	struct gdbcons *gc = arg;
1187d0c6c9fSSam Leffler 	int i;
1197d0c6c9fSSam Leffler 
1207d0c6c9fSSam Leffler 	gdb_tx_begin('O');
1217d0c6c9fSSam Leffler 	for (i = 0; i < gc->npending; i++)
1227d0c6c9fSSam Leffler 		gdb_tx_puthex(gc->buf[i]);
1237d0c6c9fSSam Leffler 	gdb_tx_end();
1247d0c6c9fSSam Leffler 	gc->npending = 0;
1257d0c6c9fSSam Leffler }
1267d0c6c9fSSam Leffler 
1277d0c6c9fSSam Leffler /*
1287d0c6c9fSSam Leffler  * This glop is to figure out when it's safe to use callouts
1297d0c6c9fSSam Leffler  * to defer buffer flushing.  There's probably a better way
1307d0c6c9fSSam Leffler  * and/or an earlier point in the boot process when it's ok.
1317d0c6c9fSSam Leffler  */
1327d0c6c9fSSam Leffler static int calloutok = 0;
1337d0c6c9fSSam Leffler static void
1347d0c6c9fSSam Leffler oktousecallout(void *data __unused)
1357d0c6c9fSSam Leffler {
1367d0c6c9fSSam Leffler 	calloutok = 1;
1377d0c6c9fSSam Leffler }
138785797c3SAndriy Gapon SYSINIT(gdbhack, SI_SUB_LAST, SI_ORDER_MIDDLE, oktousecallout, NULL);
1397d0c6c9fSSam Leffler 
1407d0c6c9fSSam Leffler static void
1417d0c6c9fSSam Leffler gdb_cnputc(struct consdev *cp, int c)
1427d0c6c9fSSam Leffler {
1437d0c6c9fSSam Leffler 	struct gdbcons *gc;
1447d0c6c9fSSam Leffler 
1457d0c6c9fSSam Leffler 	if (gdbcons_enable && gdb_cur != NULL && gdb_listening) {
1467d0c6c9fSSam Leffler 		gc = cp->cn_arg;
1477d0c6c9fSSam Leffler 		if (gc->npending != 0) {
1487d0c6c9fSSam Leffler 			/*
1497d0c6c9fSSam Leffler 			 * Cancel any pending callout and flush the
1507d0c6c9fSSam Leffler 			 * buffer if there's no space for this byte.
1517d0c6c9fSSam Leffler 			 */
1527d0c6c9fSSam Leffler 			if (calloutok)
1537d0c6c9fSSam Leffler 				callout_stop(&gc->flush);
1547d0c6c9fSSam Leffler 			if (gc->npending == sizeof(gc->buf))
1557d0c6c9fSSam Leffler 				gdb_cnflush(gc);
1567d0c6c9fSSam Leffler 		}
1577d0c6c9fSSam Leffler 		gc->buf[gc->npending++] = c;
1587d0c6c9fSSam Leffler 		/*
1597d0c6c9fSSam Leffler 		 * Flush on end of line; this is especially helpful
1607d0c6c9fSSam Leffler 		 * during boot when we don't have callouts to flush
1617d0c6c9fSSam Leffler 		 * the buffer.  Otherwise we defer flushing; a 1/4
1627d0c6c9fSSam Leffler 		 * second is a guess.
1637d0c6c9fSSam Leffler 		 */
1647d0c6c9fSSam Leffler 		if (c == '\n')
1657d0c6c9fSSam Leffler 			gdb_cnflush(gc);
1667d0c6c9fSSam Leffler 		else if (calloutok)
1677d0c6c9fSSam Leffler 			callout_reset(&gc->flush, hz/4, gdb_cnflush, gc);
1687d0c6c9fSSam Leffler 	}
1697d0c6c9fSSam Leffler }
1707d0c6c9fSSam Leffler 
1717672c959SPoul-Henning Kamp CONSOLE_DRIVER(gdb);
1727d0c6c9fSSam Leffler 
1737d0c6c9fSSam Leffler /*
1747d0c6c9fSSam Leffler  * Our console device only gets attached if the system is booted
1757d0c6c9fSSam Leffler  * with RB_MULTIPLE set so gdb_init also calls us to attach the
1767d0c6c9fSSam Leffler  * console so we're setup regardless.
1777d0c6c9fSSam Leffler  */
1787d0c6c9fSSam Leffler void
1797d0c6c9fSSam Leffler gdb_consinit(void)
1807d0c6c9fSSam Leffler {
1817d0c6c9fSSam Leffler 	gdb_cnprobe(&gdb_consdev);
1827d0c6c9fSSam Leffler 	gdb_cninit(&gdb_consdev);
1837d0c6c9fSSam Leffler 	cnadd(&gdb_consdev);
1847d0c6c9fSSam Leffler }
185