1 /* $NetBSD: zs_kgdb.c,v 1.3 2002/09/06 13:18:43 gehenna 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/param.h> 51 #include <sys/systm.h> 52 #include <sys/proc.h> 53 #include <sys/device.h> 54 #include <sys/conf.h> 55 #include <sys/ioctl.h> 56 #include <sys/kernel.h> 57 #include <sys/syslog.h> 58 #include <sys/kgdb.h> 59 60 #include <dev/ic/z8530reg.h> 61 #include <machine/z8530var.h> 62 #include <mac68k/dev/zs_cons.h> 63 64 /* 65 * Macs supposely provide a 3.672 MHz clock to the SCC. Unfortunately, 66 * empirical evidence suggests that it's really a 3.6864 MHz clock. 67 * Oh, what to do, what to do?! 68 */ 69 #define PCLK (9600 * 384) /* PCLK pin input clock rate */ 70 #define ZSHARD_PRI 4 /* Wired on the CPU board... */ 71 72 #define ZS_DELAY() delay(2) 73 74 /* The layout of this is hardware-dependent (padding, order). */ 75 struct zschan { 76 volatile u_char zc_csr; /* ctrl,status, and indirect access */ 77 u_char zc_xxx0; 78 u_char zc_xxx1; /* part of the other channel lives here! */ 79 u_char zc_xxx2; /* Yea Apple! */ 80 volatile u_char zc_data; /* data */ 81 u_char zc_xxx3; 82 u_char zc_xxx4; 83 u_char zc_xxx5; 84 }; 85 86 static void zs_setparam __P((struct zs_chanstate *, int, int)); 87 static void zskgdb __P((struct zs_chanstate *)); 88 89 struct zsops zsops_kgdb; 90 91 static u_char zs_kgdb_regs[16] = { 92 0, /* 0: CMD (reset, etc.) */ 93 0, /* 1: ~(ZSWR1_RIE | ZSWR1_TIE | ZSWR1_SIE) */ 94 0x18 + ZSHARD_PRI, /* IVECT */ 95 ZSWR3_RX_8 | ZSWR3_RX_ENABLE, 96 ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP, 97 ZSWR5_TX_8 | ZSWR5_TX_ENABLE, 98 0, /* 6: TXSYNC/SYNCLO */ 99 0, /* 7: RXSYNC/SYNCHI */ 100 0, /* 8: alias for data port */ 101 ZSWR9_MASTER_IE, 102 0, /*10: Misc. TX/RX control bits */ 103 ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD, 104 14, /*12: BAUDLO (default=9600) */ 105 0, /*13: BAUDHI (default=9600) */ 106 ZSWR14_BAUD_FROM_PCLK | ZSWR14_BAUD_ENA, 107 ZSWR15_BREAK_IE, 108 }; 109 110 /* 111 * This replaces "zs_reset()" in the sparc driver. 112 */ 113 static void 114 zs_setparam(cs, iena, rate) 115 struct zs_chanstate *cs; 116 int iena; 117 int rate; 118 { 119 int s, tconst; 120 121 bcopy(zs_kgdb_regs, cs->cs_preg, 16); 122 123 if (iena) { 124 cs->cs_preg[1] = ZSWR1_RIE | ZSWR1_SIE; 125 } 126 127 /* Initialize the speed, etc. */ 128 tconst = BPS_TO_TCONST(cs->cs_brg_clk, rate); 129 cs->cs_preg[5] |= ZSWR5_DTR | ZSWR5_RTS; 130 cs->cs_preg[12] = tconst; 131 cs->cs_preg[13] = tconst >> 8; 132 133 s = splhigh(); 134 zs_loadchannelregs(cs); 135 splx(s); 136 } 137 138 /* 139 * Set up for kgdb; called at boot time before configuration. 140 * KGDB interrupts will be enabled later when zs0 is configured. 141 * Called after cninit(), so printf() etc. works. 142 */ 143 void 144 zs_kgdb_init() 145 { 146 struct zs_chanstate cs; 147 volatile struct zschan *zc; 148 int channel; 149 extern const struct cdevsw zstty_cdevsw; 150 151 /* printf("zs_kgdb_init: kgdb_dev=0x%x\n", kgdb_dev); */ 152 if (cdevsw_lookup(kgdb_dev) != &zstty_cdevsw) 153 return; 154 155 /* Note: (ttya,ttyb) on zsc1, and (ttyc,ttyd) on zsc0 */ 156 channel = kgdb_dev & 1; 157 printf("zs_kgdb_init: attaching tty0%c at %d baud\n", 158 '0' + (kgdb_dev & 3), kgdb_rate); 159 160 if (!zsinited) 161 zs_init(); 162 163 /* Setup temporary chanstate. */ 164 bzero((caddr_t)&cs, sizeof(cs)); 165 zc = zs_get_chan_addr(0, channel); 166 if (zc == NULL) { 167 printf("zs_kgdb_init: zs not mapped.\n"); 168 kgdb_dev = -1; 169 return; 170 } 171 172 cs.cs_channel = channel; 173 cs.cs_brg_clk = PCLK / 16; 174 cs.cs_reg_csr = &zc->zc_csr; 175 cs.cs_reg_data = &zc->zc_data; 176 177 /* Now set parameters. (interrupts disabled) */ 178 zs_setparam(&cs, 0, kgdb_rate); 179 180 /* Store the getc/putc functions and arg. */ 181 kgdb_attach(zs_getc, zs_putc, (void *)zc); 182 } 183 184 /* 185 * This is a "hook" called by zstty_attach to allow the tty 186 * to be "taken over" for exclusive use by kgdb. 187 * Return non-zero if this is the kgdb port. 188 * 189 * Set the speed to kgdb_rate, CS8, etc. 190 */ 191 int 192 zs_check_kgdb(cs, dev) 193 struct zs_chanstate *cs; 194 int dev; 195 { 196 197 if (dev != kgdb_dev) 198 return (0); 199 200 /* 201 * Yes, this is port in use by kgdb. 202 */ 203 cs->cs_private = NULL; 204 cs->cs_ops = &zsops_kgdb; 205 206 /* Now set parameters. (interrupts enabled) */ 207 zs_setparam(cs, 1, kgdb_rate); 208 209 return (1); 210 } 211 212 /* 213 * KGDB framing character received: enter kernel debugger. This probably 214 * should time out after a few seconds to avoid hanging on spurious input. 215 */ 216 static void 217 zskgdb(cs) 218 struct zs_chanstate *cs; 219 { 220 int unit = minor(kgdb_dev); 221 222 printf("zstty%d: kgdb interrupt\n", unit); 223 /* This will trap into the debugger. */ 224 kgdb_connect(1); 225 } 226 227 228 /**************************************************************** 229 * Interface to the lower layer (zscc) 230 ****************************************************************/ 231 232 static void zs_kgdb_rxint __P((struct zs_chanstate *)); 233 static void zs_kgdb_stint __P((struct zs_chanstate *, int)); 234 static void zs_kgdb_txint __P((struct zs_chanstate *)); 235 static void zs_kgdb_softint __P((struct zs_chanstate *)); 236 237 int kgdb_input_lost; 238 239 static void 240 zs_kgdb_rxint(cs) 241 struct zs_chanstate *cs; 242 { 243 register u_char c, rr1; 244 245 /* 246 * First read the status, because reading the received char 247 * destroys the status of this char. 248 */ 249 rr1 = zs_read_reg(cs, 1); 250 c = zs_read_data(cs); 251 252 if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) { 253 /* Clear the receive error. */ 254 zs_write_csr(cs, ZSWR0_RESET_ERRORS); 255 } 256 257 if (c == KGDB_START) { 258 zskgdb(cs); 259 } else { 260 kgdb_input_lost++; 261 } 262 } 263 264 static void 265 zs_kgdb_txint(cs) 266 register struct zs_chanstate *cs; 267 { 268 register int rr0; 269 270 rr0 = zs_read_csr(cs); 271 zs_write_csr(cs, ZSWR0_RESET_TXINT); 272 } 273 274 static void 275 zs_kgdb_stint(cs, force) 276 register struct zs_chanstate *cs; 277 int force; 278 { 279 register int rr0; 280 281 rr0 = zs_read_csr(cs); 282 zs_write_csr(cs, ZSWR0_RESET_STATUS); 283 284 /* 285 * Check here for console break, so that we can abort 286 * even when interrupts are locking up the machine. 287 */ 288 if (rr0 & ZSRR0_BREAK) { 289 zskgdb(cs); 290 } 291 } 292 293 static void 294 zs_kgdb_softint(cs) 295 struct zs_chanstate *cs; 296 { 297 printf("zs_kgdb_softint?\n"); 298 } 299 300 struct zsops zsops_kgdb = { 301 zs_kgdb_rxint, /* receive char available */ 302 zs_kgdb_stint, /* external/status */ 303 zs_kgdb_txint, /* xmit buffer empty */ 304 zs_kgdb_softint, /* process software interrupt */ 305 }; 306