1 /* $NetBSD: zs_kgdb.c,v 1.11 2023/10/24 19:05:07 andvar Exp $ */
2
3 /*-
4 * Copyright (c) 1996 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Gordon W. Ross.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 /*
33 * Hooks for kgdb when attached via the z8530 driver
34 *
35 * To use this, build a kernel with: option KGDB, and
36 * boot that kernel with "-d". (The kernel will call
37 * zs_kgdb_init, kgdb_connect.) When the console prints
38 * "kgdb waiting..." you run "gdb -k kernel" and do:
39 * (gdb) set remotebaud 19200
40 * (gdb) target remote /dev/ttyb
41 */
42
43 #include <sys/cdefs.h>
44 __KERNEL_RCSID(0, "$NetBSD: zs_kgdb.c,v 1.11 2023/10/24 19:05:07 andvar Exp $");
45
46 #include "opt_kgdb.h"
47
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/proc.h>
51 #include <sys/device.h>
52 #include <sys/conf.h>
53 #include <sys/ioctl.h>
54 #include <sys/kernel.h>
55 #include <sys/syslog.h>
56 #include <sys/kgdb.h>
57
58 #include <dev/ic/z8530reg.h>
59 #include <machine/z8530var.h>
60 #include <machine/promlib.h>
61 #include <sun2/dev/cons.h>
62
63 static void zs_setparam(struct zs_chanstate *, int, int);
64 struct zsops zsops_kgdb;
65
66 extern int zs_getc(void *arg);
67 extern void zs_putc(void *arg, int c);
68
69 static u_char zs_kgdb_regs[16] = {
70 0, /* 0: CMD (reset, etc.) */
71 0, /* 1: No interrupts yet. */
72 #ifdef ZS_INIT_IVECT
73 ZS_INIT_IVECT, /* 2: IVECT */
74 #else
75 0, /* 2: IVECT */
76 #endif
77 ZSWR3_RX_8 | ZSWR3_RX_ENABLE,
78 ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP,
79 ZSWR5_TX_8 | ZSWR5_TX_ENABLE,
80 0, /* 6: TXSYNC/SYNCLO */
81 0, /* 7: RXSYNC/SYNCHI */
82 0, /* 8: alias for data port */
83 #ifdef ZS_INIT_IVECT
84 ZSWR9_MASTER_IE,
85 #else
86 ZSWR9_MASTER_IE | ZSWR9_NO_VECTOR,
87 #endif
88 0, /*10: Misc. TX/RX control bits */
89 ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,
90 14, /*12: BAUDLO (default=9600) */
91 0, /*13: BAUDHI (default=9600) */
92 ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK,
93 ZSWR15_BREAK_IE,
94 };
95
96 /*
97 * This replaces "zs_reset()" in the sparc driver.
98 */
99 static void
zs_setparam(struct zs_chanstate * cs,int iena,int rate)100 zs_setparam(struct zs_chanstate *cs, int iena, int rate)
101 {
102 int s, tconst;
103
104 memcpy(cs->cs_preg, zs_kgdb_regs, 16);
105
106 if (iena) {
107 cs->cs_preg[1] = ZSWR1_RIE | ZSWR1_SIE;
108 }
109
110 /* Initialize the speed, etc. */
111 tconst = BPS_TO_TCONST(cs->cs_brg_clk, rate);
112 cs->cs_preg[5] |= ZSWR5_DTR | ZSWR5_RTS;
113 cs->cs_preg[12] = tconst;
114 cs->cs_preg[13] = tconst >> 8;
115
116 s = splhigh();
117 zs_loadchannelregs(cs);
118 splx(s);
119 }
120
121 /*
122 * Set up for kgdb; called at boot time before configuration.
123 * KGDB interrupts will be enabled later when zs0 is configured.
124 * Called after cninit(), so printf() etc. works.
125 */
126 void
zs_kgdb_init(void)127 zs_kgdb_init(void)
128 {
129 struct zs_chanstate cs;
130 struct zsdevice *zsd;
131 volatile struct zschan *zc;
132 int channel, promzs_unit;
133 extern const struct cdevsw zstty_cdevsw;
134
135 /* printf("zs_kgdb_init: kgdb_dev=0x%llx\n", kgdb_dev); */
136 if (cdevsw_lookup(kgdb_dev) != &zstty_cdevsw)
137 return;
138
139 /* Note: (ttya,ttyb) on zs0, and (ttyc,ttyd) on zs2 */
140 promzs_unit = (kgdb_dev & 2) ? 2 : 0;
141 channel = kgdb_dev & 1;
142 printf("zs_kgdb_init: attaching Serial(%lld) at %d baud\n",
143 (kgdb_dev & 3), kgdb_rate);
144
145 /* Setup temporary chanstate. */
146 memset((void *)&cs, 0, sizeof(cs));
147 zsd = zs_find_prom(promzs_unit);
148 if (zsd == NULL) {
149 printf("zs_kgdb_init: zs not mapped.\n");
150 return;
151 }
152 zc = (channel == 0) ? &zsd->zs_chan_a : &zsd->zs_chan_b;
153
154 cs.cs_channel = channel;
155 cs.cs_brg_clk = PCLK / 16;
156 cs.cs_reg_csr = &zc->zc_csr;
157 cs.cs_reg_data = &zc->zc_data;
158
159 /* Now set parameters. (interrupts disabled) */
160 zs_setparam(&cs, 0, kgdb_rate);
161
162 /* Store the getc/putc functions and arg. */
163 kgdb_attach(zs_getc, zs_putc, __UNVOLATILE(zc));
164 }
165
166 /*
167 * This is a "hook" called by zstty_attach to allow the tty
168 * to be "taken over" for exclusive use by kgdb.
169 * Return non-zero if this is the kgdb port.
170 *
171 * Set the speed to kgdb_rate, CS8, etc.
172 */
173 int
zs_check_kgdb(struct zs_chanstate * cs,int dev)174 zs_check_kgdb(struct zs_chanstate *cs, int dev)
175 {
176
177 if (dev != kgdb_dev)
178 return (0);
179
180 /*
181 * Yes, this is port in use by kgdb.
182 */
183 cs->cs_private = NULL;
184 cs->cs_ops = &zsops_kgdb;
185
186 /* Now set parameters. (interrupts enabled) */
187 zs_setparam(cs, 1, kgdb_rate);
188
189 return (1);
190 }
191
192 /*
193 * KGDB framing character received: enter kernel debugger. This probably
194 * should time out after a few seconds to avoid hanging on spurious input.
195 */
196 void
zskgdb(struct zs_chanstate * cs)197 zskgdb(struct zs_chanstate *cs)
198 {
199 int unit = minor(kgdb_dev);
200
201 printf("zstty%d: kgdb interrupt\n", unit);
202 /* This will trap into the debugger. */
203 kgdb_connect(1);
204 }
205
206
207 /****************************************************************
208 * Interface to the lower layer (zscc)
209 ****************************************************************/
210
211 static void zs_kgdb_rxint(struct zs_chanstate *);
212 static void zs_kgdb_stint(struct zs_chanstate *, int);
213 static void zs_kgdb_txint(struct zs_chanstate *);
214 static void zs_kgdb_softint(struct zs_chanstate *);
215
216 int kgdb_input_lost;
217
218 static void
zs_kgdb_rxint(struct zs_chanstate * cs)219 zs_kgdb_rxint(struct zs_chanstate *cs)
220 {
221 u_char c, rr1;
222
223 /*
224 * First read the status, because reading the received char
225 * destroys the status of this char.
226 */
227 rr1 = zs_read_reg(cs, 1);
228 c = zs_read_data(cs);
229
230 if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) {
231 /* Clear the receive error. */
232 zs_write_csr(cs, ZSWR0_RESET_ERRORS);
233 }
234
235 if (c == KGDB_START) {
236 zskgdb(cs);
237 } else {
238 kgdb_input_lost++;
239 }
240 }
241
242 static void
zs_kgdb_txint(struct zs_chanstate * cs)243 zs_kgdb_txint(struct zs_chanstate *cs)
244 {
245 zs_write_csr(cs, ZSWR0_RESET_TXINT);
246 }
247
248 static void
zs_kgdb_stint(struct zs_chanstate * cs,int force)249 zs_kgdb_stint(struct zs_chanstate *cs, int force)
250 {
251 int rr0;
252
253 rr0 = zs_read_csr(cs);
254 zs_write_csr(cs, ZSWR0_RESET_STATUS);
255
256 /*
257 * Check here for console break, so that we can abort
258 * even when interrupts are locking up the machine.
259 */
260 if (rr0 & ZSRR0_BREAK) {
261 zskgdb(cs);
262 }
263 }
264
265 static void
zs_kgdb_softint(struct zs_chanstate * cs)266 zs_kgdb_softint(struct zs_chanstate *cs)
267 {
268 printf("zs_kgdb_softint?\n");
269 }
270
271 struct zsops zsops_kgdb = {
272 zs_kgdb_rxint, /* receive char available */
273 zs_kgdb_stint, /* external/status */
274 zs_kgdb_txint, /* xmit buffer empty */
275 zs_kgdb_softint, /* process software interrupt */
276 };
277