1 /* $NetBSD: zs_kgdb.c,v 1.28 2024/12/20 23:52:00 tsutsui 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 1.28 2024/12/20 23:52:00 tsutsui 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 <sun3/dev/zs_cons.h> 61 62 /* The Sun3 provides a 4.9152 MHz clock to the ZS chips. */ 63 #define PCLK (9600 * 512) /* PCLK pin input clock rate */ 64 #define ZSHARD_PRI 6 /* Wired on the CPU board... */ 65 66 #define ZS_DELAY() delay(2) 67 68 /* The layout of this is hardware-dependent (padding, order). */ 69 struct zschan { 70 volatile u_char zc_csr; /* ctrl,status, and indirect access */ 71 u_char zc_xxx0; 72 volatile u_char zc_data; /* data */ 73 u_char zc_xxx1; 74 }; 75 76 static void zs_setparam(struct zs_chanstate *, int, int); 77 static void zskgdb(struct zs_chanstate *); 78 79 struct zsops zsops_kgdb; 80 81 static u_char zs_kgdb_regs[16] = { 82 0, /* 0: CMD (reset, etc.) */ 83 0, /* 1: ~(ZSWR1_RIE | ZSWR1_TIE | ZSWR1_SIE) */ 84 0x18 + ZSHARD_PRI, /* IVECT */ 85 ZSWR3_RX_8 | ZSWR3_RX_ENABLE, 86 ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP, 87 ZSWR5_TX_8 | ZSWR5_TX_ENABLE, 88 0, /* 6: TXSYNC/SYNCLO */ 89 0, /* 7: RXSYNC/SYNCHI */ 90 0, /* 8: alias for data port */ 91 ZSWR9_MASTER_IE, 92 0, /*10: Misc. TX/RX control bits */ 93 ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD, 94 14, /*12: BAUDLO (default=9600) */ 95 0, /*13: BAUDHI (default=9600) */ 96 ZSWR14_BAUD_FROM_PCLK | ZSWR14_BAUD_ENA, 97 ZSWR15_BREAK_IE, 98 }; 99 100 /* 101 * This replaces "zs_reset()" in the sparc driver. 102 */ 103 static void 104 zs_setparam(struct zs_chanstate *cs, int iena, int rate) 105 { 106 int s, tconst; 107 108 memcpy(cs->cs_preg, zs_kgdb_regs, 16); 109 110 if (iena) { 111 cs->cs_preg[1] = ZSWR1_RIE | ZSWR1_SIE; 112 } 113 114 /* Initialize the speed, etc. */ 115 tconst = BPS_TO_TCONST(cs->cs_brg_clk, rate); 116 cs->cs_preg[5] |= ZSWR5_DTR | ZSWR5_RTS; 117 cs->cs_preg[12] = tconst; 118 cs->cs_preg[13] = tconst >> 8; 119 120 s = splhigh(); 121 zs_loadchannelregs(cs); 122 splx(s); 123 } 124 125 /* 126 * Set up for kgdb; called at boot time before configuration. 127 * KGDB interrupts will be enabled later when zs0 is configured. 128 * Called after cninit(), so printf() etc. works. 129 */ 130 void 131 zs_kgdb_init(void) 132 { 133 struct zs_chanstate cs; 134 struct zschan *zc; 135 int channel, zsc_unit; 136 extern const struct cdevsw zstty_cdevsw; 137 138 /* printf("zs_kgdb_init: kgdb_dev=0x%x\n", kgdb_dev); */ 139 if (cdevsw_lookup(kgdb_dev) != &zstty_cdevsw) 140 return; 141 142 /* Note: (ttya,ttyb) on zsc1, and (ttyc,ttyd) on zsc0 */ 143 zsc_unit = (kgdb_dev & 2) ? 0 : 1; 144 channel = kgdb_dev & 1; 145 printf("zs_kgdb_init: attaching tty%c at %d baud\n", 146 'a' + ((int)kgdb_dev & 3), kgdb_rate); 147 148 /* Setup temporary chanstate. */ 149 memset((void *)&cs, 0, sizeof(cs)); 150 zc = zs_get_chan_addr(zsc_unit, channel); 151 if (zc == NULL) { 152 printf("zs_kgdb_init: zs not mapped.\n"); 153 kgdb_dev = -1; 154 return; 155 } 156 157 cs.cs_channel = channel; 158 cs.cs_brg_clk = PCLK / 16; 159 cs.cs_reg_csr = &zc->zc_csr; 160 cs.cs_reg_data = &zc->zc_data; 161 162 /* Now set parameters. (interrupts disabled) */ 163 zs_setparam(&cs, 0, kgdb_rate); 164 165 /* Store the getc/putc functions and arg. */ 166 kgdb_attach(zs_getc, zs_putc, __UNVOLATILE(zc)); 167 } 168 169 /* 170 * This is a "hook" called by zstty_attach to allow the tty 171 * to be "taken over" for exclusive use by kgdb. 172 * Return non-zero if this is the kgdb port. 173 * 174 * Set the speed to kgdb_rate, CS8, etc. 175 */ 176 int 177 zs_check_kgdb(struct zs_chanstate *cs, int dev) 178 { 179 180 if (dev != kgdb_dev) 181 return (0); 182 183 /* 184 * Yes, this is port in use by kgdb. 185 */ 186 cs->cs_private = NULL; 187 cs->cs_ops = &zsops_kgdb; 188 189 /* Now set parameters. (interrupts enabled) */ 190 zs_setparam(cs, 1, kgdb_rate); 191 192 return (1); 193 } 194 195 /* 196 * KGDB framing character received: enter kernel debugger. This probably 197 * should time out after a few seconds to avoid hanging on spurious input. 198 */ 199 static void 200 zskgdb(struct zs_chanstate *cs) 201 { 202 int unit = minor(kgdb_dev); 203 204 printf("zstty%d: kgdb interrupt\n", unit); 205 /* This will trap into the debugger. */ 206 kgdb_connect(1); 207 } 208 209 210 /**************************************************************** 211 * Interface to the lower layer (zscc) 212 ****************************************************************/ 213 214 static void zs_kgdb_rxint(struct zs_chanstate *); 215 static void zs_kgdb_stint(struct zs_chanstate *, int); 216 static void zs_kgdb_txint(struct zs_chanstate *); 217 static void zs_kgdb_softint(struct zs_chanstate *); 218 219 int kgdb_input_lost; 220 221 static void 222 zs_kgdb_rxint(struct zs_chanstate *cs) 223 { 224 u_char c, rr1; 225 226 /* 227 * First read the status, because reading the received char 228 * destroys the status of this char. 229 */ 230 rr1 = zs_read_reg(cs, 1); 231 c = zs_read_data(cs); 232 233 if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) { 234 /* Clear the receive error. */ 235 zs_write_csr(cs, ZSWR0_RESET_ERRORS); 236 } 237 238 if (c == KGDB_START) { 239 zskgdb(cs); 240 } else { 241 kgdb_input_lost++; 242 } 243 } 244 245 static void 246 zs_kgdb_txint(struct zs_chanstate *cs) 247 { 248 zs_write_csr(cs, ZSWR0_RESET_TXINT); 249 } 250 251 static void 252 zs_kgdb_stint(struct zs_chanstate *cs, int force) 253 { 254 int rr0; 255 256 rr0 = zs_read_csr(cs); 257 zs_write_csr(cs, ZSWR0_RESET_STATUS); 258 259 /* 260 * Check here for console break, so that we can abort 261 * even when interrupts are locking up the machine. 262 */ 263 if (rr0 & ZSRR0_BREAK) { 264 zskgdb(cs); 265 } 266 } 267 268 static void 269 zs_kgdb_softint(struct zs_chanstate *cs) 270 { 271 printf("zs_kgdb_softint?\n"); 272 } 273 274 struct zsops zsops_kgdb = { 275 zs_kgdb_rxint, /* receive char available */ 276 zs_kgdb_stint, /* external/status */ 277 zs_kgdb_txint, /* xmit buffer empty */ 278 zs_kgdb_softint, /* process software interrupt */ 279 }; 280