1 /* $NetBSD: zs_kgdb.c,v 1.8 2005/12/11 12:18:03 christos 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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 /* 40 * Hooks for kgdb when attached via the z8530 driver 41 * 42 * To use this, build a kernel with: option KGDB, and 43 * boot that kernel with "-d". (The kernel will call 44 * zs_kgdb_init, kgdb_connect.) When the console prints 45 * "kgdb waiting..." you run "gdb -k kernel" and do: 46 * (gdb) set remotebaud 19200 47 * (gdb) target remote /dev/ttyb 48 */ 49 50 #include <sys/cdefs.h> 51 __KERNEL_RCSID(0, "$NetBSD: zs_kgdb.c,v 1.8 2005/12/11 12:18:03 christos Exp $"); 52 53 #include "opt_kgdb.h" 54 #include <sys/param.h> 55 #include <sys/systm.h> 56 #include <sys/proc.h> 57 #include <sys/device.h> 58 #include <sys/conf.h> 59 #include <sys/ioctl.h> 60 #include <sys/kernel.h> 61 #include <sys/syslog.h> 62 #include <sys/kgdb.h> 63 64 #include <dev/ic/z8530reg.h> 65 #include <machine/z8530var.h> 66 #include <mac68k/dev/zs_cons.h> 67 68 /* 69 * Macs supposely provide a 3.672 MHz clock to the SCC. Unfortunately, 70 * empirical evidence suggests that it's really a 3.6864 MHz clock. 71 * Oh, what to do, what to do?! 72 */ 73 #define PCLK (9600 * 384) /* PCLK pin input clock rate */ 74 #define ZSHARD_PRI 4 /* Wired on the CPU board... */ 75 76 #define ZS_DELAY() delay(2) 77 78 /* The layout of this is hardware-dependent (padding, order). */ 79 struct zschan { 80 volatile u_char zc_csr; /* ctrl,status, and indirect access */ 81 u_char zc_xxx0; 82 u_char zc_xxx1; /* part of the other channel lives here! */ 83 u_char zc_xxx2; /* Yea Apple! */ 84 volatile u_char zc_data; /* data */ 85 u_char zc_xxx3; 86 u_char zc_xxx4; 87 u_char zc_xxx5; 88 }; 89 90 static void zs_setparam(struct zs_chanstate *, int, int); 91 static void zskgdb(struct zs_chanstate *); 92 93 struct zsops zsops_kgdb; 94 95 static u_char zs_kgdb_regs[16] = { 96 0, /* 0: CMD (reset, etc.) */ 97 0, /* 1: ~(ZSWR1_RIE | ZSWR1_TIE | ZSWR1_SIE) */ 98 0x18 + ZSHARD_PRI, /* IVECT */ 99 ZSWR3_RX_8 | ZSWR3_RX_ENABLE, 100 ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP, 101 ZSWR5_TX_8 | ZSWR5_TX_ENABLE, 102 0, /* 6: TXSYNC/SYNCLO */ 103 0, /* 7: RXSYNC/SYNCHI */ 104 0, /* 8: alias for data port */ 105 ZSWR9_MASTER_IE, 106 0, /*10: Misc. TX/RX control bits */ 107 ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD, 108 14, /*12: BAUDLO (default=9600) */ 109 0, /*13: BAUDHI (default=9600) */ 110 ZSWR14_BAUD_FROM_PCLK | ZSWR14_BAUD_ENA, 111 ZSWR15_BREAK_IE, 112 }; 113 114 /* 115 * This replaces "zs_reset()" in the sparc driver. 116 */ 117 static void 118 zs_setparam(struct zs_chanstate *cs, int iena, int rate) 119 { 120 int s, tconst; 121 122 memcpy(cs->cs_preg, zs_kgdb_regs, 16); 123 124 if (iena) { 125 cs->cs_preg[1] = ZSWR1_RIE | ZSWR1_SIE; 126 } 127 128 /* Initialize the speed, etc. */ 129 tconst = BPS_TO_TCONST(cs->cs_brg_clk, rate); 130 cs->cs_preg[5] |= ZSWR5_DTR | ZSWR5_RTS; 131 cs->cs_preg[12] = tconst; 132 cs->cs_preg[13] = tconst >> 8; 133 134 s = splhigh(); 135 zs_loadchannelregs(cs); 136 splx(s); 137 } 138 139 /* 140 * Set up for kgdb; called at boot time before configuration. 141 * KGDB interrupts will be enabled later when zs0 is configured. 142 * Called after cninit(), so printf() etc. works. 143 */ 144 void 145 zs_kgdb_init(void) 146 { 147 struct zs_chanstate cs; 148 volatile struct zschan *zc; 149 int channel; 150 extern const struct cdevsw zstty_cdevsw; 151 152 /* printf("zs_kgdb_init: kgdb_dev=0x%x\n", kgdb_dev); */ 153 if (cdevsw_lookup(kgdb_dev) != &zstty_cdevsw) 154 return; 155 156 /* Note: (ttya,ttyb) on zsc1, and (ttyc,ttyd) on zsc0 */ 157 channel = kgdb_dev & 1; 158 printf("zs_kgdb_init: attaching tty0%c at %d baud\n", 159 '0' + (kgdb_dev & 3), kgdb_rate); 160 161 if (!zsinited) 162 zs_init(); 163 164 /* Setup temporary chanstate. */ 165 memset(&cs, 0, sizeof(cs)); 166 zc = zs_get_chan_addr(channel); 167 if (zc == NULL) { 168 printf("zs_kgdb_init: zs not mapped.\n"); 169 kgdb_dev = -1; 170 return; 171 } 172 173 cs.cs_channel = channel; 174 cs.cs_brg_clk = PCLK / 16; 175 cs.cs_reg_csr = &zc->zc_csr; 176 cs.cs_reg_data = &zc->zc_data; 177 178 /* Now set parameters. (interrupts disabled) */ 179 zs_setparam(&cs, 0, kgdb_rate); 180 181 /* Store the getc/putc functions and arg. */ 182 kgdb_attach(zs_getc, zs_putc, (void *)zc); 183 } 184 185 /* 186 * This is a "hook" called by zstty_attach to allow the tty 187 * to be "taken over" for exclusive use by kgdb. 188 * Return non-zero if this is the kgdb port. 189 * 190 * Set the speed to kgdb_rate, CS8, etc. 191 */ 192 int 193 zs_check_kgdb(struct zs_chanstate *cs, int dev) 194 { 195 196 if (dev != kgdb_dev) 197 return (0); 198 199 /* 200 * Yes, this is port in use by kgdb. 201 */ 202 cs->cs_private = NULL; 203 cs->cs_ops = &zsops_kgdb; 204 205 /* Now set parameters. (interrupts enabled) */ 206 zs_setparam(cs, 1, kgdb_rate); 207 208 return (1); 209 } 210 211 /* 212 * KGDB framing character received: enter kernel debugger. This probably 213 * should time out after a few seconds to avoid hanging on spurious input. 214 */ 215 static void 216 zskgdb(struct zs_chanstate *cs) 217 { 218 int unit = minor(kgdb_dev); 219 220 printf("zstty%d: kgdb interrupt\n", unit); 221 /* This will trap into the debugger. */ 222 kgdb_connect(1); 223 } 224 225 226 /**************************************************************** 227 * Interface to the lower layer (zscc) 228 ****************************************************************/ 229 230 static void zs_kgdb_rxint(struct zs_chanstate *); 231 static void zs_kgdb_stint(struct zs_chanstate *, int); 232 static void zs_kgdb_txint(struct zs_chanstate *); 233 static void zs_kgdb_softint(struct zs_chanstate *); 234 235 int kgdb_input_lost; 236 237 static void 238 zs_kgdb_rxint(struct zs_chanstate *cs) 239 { 240 u_char c, rr1; 241 242 /* 243 * First read the status, because reading the received char 244 * destroys the status of this char. 245 */ 246 rr1 = zs_read_reg(cs, 1); 247 c = zs_read_data(cs); 248 249 if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) { 250 /* Clear the receive error. */ 251 zs_write_csr(cs, ZSWR0_RESET_ERRORS); 252 } 253 254 if (c == KGDB_START) { 255 zskgdb(cs); 256 } else { 257 kgdb_input_lost++; 258 } 259 } 260 261 static void 262 zs_kgdb_txint(struct zs_chanstate *cs) 263 { 264 int rr0; 265 266 rr0 = zs_read_csr(cs); 267 zs_write_csr(cs, ZSWR0_RESET_TXINT); 268 } 269 270 static void 271 zs_kgdb_stint(struct zs_chanstate *cs, int force) 272 { 273 int rr0; 274 275 rr0 = zs_read_csr(cs); 276 zs_write_csr(cs, ZSWR0_RESET_STATUS); 277 278 /* 279 * Check here for console break, so that we can abort 280 * even when interrupts are locking up the machine. 281 */ 282 if (rr0 & ZSRR0_BREAK) { 283 zskgdb(cs); 284 } 285 } 286 287 static void 288 zs_kgdb_softint(struct zs_chanstate *cs) 289 { 290 printf("zs_kgdb_softint?\n"); 291 } 292 293 struct zsops zsops_kgdb = { 294 zs_kgdb_rxint, /* receive char available */ 295 zs_kgdb_stint, /* external/status */ 296 zs_kgdb_txint, /* xmit buffer empty */ 297 zs_kgdb_softint, /* process software interrupt */ 298 }; 299