1 /* $NetBSD: zs_kgdb.c,v 1.11 2008/04/28 20:23:27 martin 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 2008/04/28 20:23:27 martin Exp $"); 45 46 #include "opt_kgdb.h" 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/proc.h> 50 #include <sys/device.h> 51 #include <sys/conf.h> 52 #include <sys/ioctl.h> 53 #include <sys/kernel.h> 54 #include <sys/syslog.h> 55 #include <sys/kgdb.h> 56 57 #include <dev/ic/z8530reg.h> 58 #include <machine/z8530var.h> 59 #include <mac68k/dev/zs_cons.h> 60 61 /* 62 * Macs supposely provide a 3.672 MHz clock to the SCC. Unfortunately, 63 * empirical evidence suggests that it's really a 3.6864 MHz clock. 64 * Oh, what to do, what to do?! 65 */ 66 #define PCLK (9600 * 384) /* PCLK pin input clock rate */ 67 #define ZSHARD_PRI 4 /* Wired on the CPU board... */ 68 69 #define ZS_DELAY() delay(2) 70 71 /* The layout of this is hardware-dependent (padding, order). */ 72 struct zschan { 73 volatile u_char zc_csr; /* ctrl,status, and indirect access */ 74 u_char zc_xxx0; 75 u_char zc_xxx1; /* part of the other channel lives here! */ 76 u_char zc_xxx2; /* Yea Apple! */ 77 volatile u_char zc_data; /* data */ 78 u_char zc_xxx3; 79 u_char zc_xxx4; 80 u_char zc_xxx5; 81 }; 82 83 static void zs_setparam(struct zs_chanstate *, int, int); 84 static void zskgdb(struct zs_chanstate *); 85 86 struct zsops zsops_kgdb; 87 88 static u_char zs_kgdb_regs[16] = { 89 0, /* 0: CMD (reset, etc.) */ 90 0, /* 1: ~(ZSWR1_RIE | ZSWR1_TIE | ZSWR1_SIE) */ 91 0x18 + ZSHARD_PRI, /* IVECT */ 92 ZSWR3_RX_8 | ZSWR3_RX_ENABLE, 93 ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP, 94 ZSWR5_TX_8 | ZSWR5_TX_ENABLE, 95 0, /* 6: TXSYNC/SYNCLO */ 96 0, /* 7: RXSYNC/SYNCHI */ 97 0, /* 8: alias for data port */ 98 ZSWR9_MASTER_IE, 99 0, /*10: Misc. TX/RX control bits */ 100 ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD, 101 14, /*12: BAUDLO (default=9600) */ 102 0, /*13: BAUDHI (default=9600) */ 103 ZSWR14_BAUD_FROM_PCLK | ZSWR14_BAUD_ENA, 104 ZSWR15_BREAK_IE, 105 }; 106 107 /* 108 * This replaces "zs_reset()" in the sparc driver. 109 */ 110 static void 111 zs_setparam(struct zs_chanstate *cs, int iena, int rate) 112 { 113 int s, tconst; 114 115 memcpy(cs->cs_preg, zs_kgdb_regs, 16); 116 117 if (iena) { 118 cs->cs_preg[1] = ZSWR1_RIE | ZSWR1_SIE; 119 } 120 121 /* Initialize the speed, etc. */ 122 tconst = BPS_TO_TCONST(cs->cs_brg_clk, rate); 123 cs->cs_preg[5] |= ZSWR5_DTR | ZSWR5_RTS; 124 cs->cs_preg[12] = tconst; 125 cs->cs_preg[13] = tconst >> 8; 126 127 s = splhigh(); 128 zs_loadchannelregs(cs); 129 splx(s); 130 } 131 132 /* 133 * Set up for kgdb; called at boot time before configuration. 134 * KGDB interrupts will be enabled later when zs0 is configured. 135 * Called after cninit(), so printf() etc. works. 136 */ 137 void 138 zs_kgdb_init(void) 139 { 140 struct zs_chanstate cs; 141 volatile struct zschan *zc; 142 int channel; 143 extern const struct cdevsw zstty_cdevsw; 144 145 /* printf("zs_kgdb_init: kgdb_dev=0x%x\n", kgdb_dev); */ 146 if (cdevsw_lookup(kgdb_dev) != &zstty_cdevsw) 147 return; 148 149 /* Note: (ttya,ttyb) on zsc1, and (ttyc,ttyd) on zsc0 */ 150 channel = kgdb_dev & 1; 151 printf("zs_kgdb_init: attaching tty0%c at %d baud\n", 152 '0' + (kgdb_dev & 3), kgdb_rate); 153 154 if (!zsinited) 155 zs_init(); 156 157 /* Setup temporary chanstate. */ 158 memset(&cs, 0, sizeof(cs)); 159 zc = zs_get_chan_addr(channel); 160 if (zc == NULL) { 161 printf("zs_kgdb_init: zs not mapped.\n"); 162 kgdb_dev = -1; 163 return; 164 } 165 166 cs.cs_channel = channel; 167 cs.cs_brg_clk = PCLK / 16; 168 cs.cs_reg_csr = &zc->zc_csr; 169 cs.cs_reg_data = &zc->zc_data; 170 171 /* Now set parameters. (interrupts disabled) */ 172 zs_setparam(&cs, 0, kgdb_rate); 173 174 /* Store the getc/putc functions and arg. */ 175 kgdb_attach(zs_getc, zs_putc, __UNVOLATILE(zc)); 176 } 177 178 /* 179 * This is a "hook" called by zstty_attach to allow the tty 180 * to be "taken over" for exclusive use by kgdb. 181 * Return non-zero if this is the kgdb port. 182 * 183 * Set the speed to kgdb_rate, CS8, etc. 184 */ 185 int 186 zs_check_kgdb(struct zs_chanstate *cs, int dev) 187 { 188 189 if (dev != kgdb_dev) 190 return (0); 191 192 /* 193 * Yes, this is port in use by kgdb. 194 */ 195 cs->cs_private = NULL; 196 cs->cs_ops = &zsops_kgdb; 197 198 /* Now set parameters. (interrupts enabled) */ 199 zs_setparam(cs, 1, kgdb_rate); 200 201 return (1); 202 } 203 204 /* 205 * KGDB framing character received: enter kernel debugger. This probably 206 * should time out after a few seconds to avoid hanging on spurious input. 207 */ 208 static void 209 zskgdb(struct zs_chanstate *cs) 210 { 211 int unit = minor(kgdb_dev); 212 213 printf("zstty%d: kgdb interrupt\n", unit); 214 /* This will trap into the debugger. */ 215 kgdb_connect(1); 216 } 217 218 219 /**************************************************************** 220 * Interface to the lower layer (zscc) 221 ****************************************************************/ 222 223 static void zs_kgdb_rxint(struct zs_chanstate *); 224 static void zs_kgdb_stint(struct zs_chanstate *, int); 225 static void zs_kgdb_txint(struct zs_chanstate *); 226 static void zs_kgdb_softint(struct zs_chanstate *); 227 228 int kgdb_input_lost; 229 230 static void 231 zs_kgdb_rxint(struct zs_chanstate *cs) 232 { 233 u_char c, rr1; 234 235 /* 236 * First read the status, because reading the received char 237 * destroys the status of this char. 238 */ 239 rr1 = zs_read_reg(cs, 1); 240 c = zs_read_data(cs); 241 242 if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) { 243 /* Clear the receive error. */ 244 zs_write_csr(cs, ZSWR0_RESET_ERRORS); 245 } 246 247 if (c == KGDB_START) { 248 zskgdb(cs); 249 } else { 250 kgdb_input_lost++; 251 } 252 } 253 254 static void 255 zs_kgdb_txint(struct zs_chanstate *cs) 256 { 257 int rr0; 258 259 rr0 = zs_read_csr(cs); 260 zs_write_csr(cs, ZSWR0_RESET_TXINT); 261 } 262 263 static void 264 zs_kgdb_stint(struct zs_chanstate *cs, int force) 265 { 266 int rr0; 267 268 rr0 = zs_read_csr(cs); 269 zs_write_csr(cs, ZSWR0_RESET_STATUS); 270 271 /* 272 * Check here for console break, so that we can abort 273 * even when interrupts are locking up the machine. 274 */ 275 if (rr0 & ZSRR0_BREAK) { 276 zskgdb(cs); 277 } 278 } 279 280 static void 281 zs_kgdb_softint(struct zs_chanstate *cs) 282 { 283 printf("zs_kgdb_softint?\n"); 284 } 285 286 struct zsops zsops_kgdb = { 287 zs_kgdb_rxint, /* receive char available */ 288 zs_kgdb_stint, /* external/status */ 289 zs_kgdb_txint, /* xmit buffer empty */ 290 zs_kgdb_softint, /* process software interrupt */ 291 }; 292