1 /* $NetBSD: zs_kgdb.c,v 1.2 2002/05/17 06:44:03 jdolecek 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 "opt_kgdb.h" 51 52 #include <sys/param.h> 53 #include <sys/systm.h> 54 #include <sys/proc.h> 55 #include <sys/device.h> 56 #include <sys/conf.h> 57 #include <sys/ioctl.h> 58 #include <sys/kernel.h> 59 #include <sys/syslog.h> 60 #include <sys/kgdb.h> 61 62 #include <machine/cpu.h> 63 64 #include <dev/ic/z8530reg.h> 65 #include <machine/z8530var.h> 66 #include <next68k/dev/zs_cons.h> 67 68 /* 69 * The NeXT provides a 3.686400 MHz clock to the ZS chips. 70 */ 71 #define PCLK (9600 * 384) /* PCLK pin input clock rate */ 72 73 /* The layout of this is hardware-dependent (padding, order). */ 74 struct zschan { 75 volatile u_char zc_csr; /* ctrl,status, and indirect access */ 76 u_char zc_xxx0; 77 volatile u_char zc_data; /* data */ 78 u_char zc_xxx1; 79 }; 80 81 static void zs_setparam __P((struct zs_chanstate *, int, int)); 82 struct zsops zsops_kgdb; 83 84 static u_char zs_kgdb_regs[16] = { 85 0, /* 0: CMD (reset, etc.) */ 86 0, /* 1: No interrupts yet. */ 87 0x18 + NEXT_I_IPL(NEXT_I_SCC), /* 2: IVECT */ 88 ZSWR3_RX_8 | ZSWR3_RX_ENABLE, 89 ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP, 90 ZSWR5_TX_8 | ZSWR5_TX_ENABLE, 91 0, /* 6: TXSYNC/SYNCLO */ 92 0, /* 7: RXSYNC/SYNCHI */ 93 0, /* 8: alias for data port */ 94 ZSWR9_MASTER_IE, 95 0, /*10: Misc. TX/RX control bits */ 96 ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD, 97 ((PCLK/32)/9600)-2, /*12: BAUDLO (default=9600) */ 98 0, /*13: BAUDHI (default=9600) */ 99 ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK, 100 ZSWR15_BREAK_IE, 101 }; 102 103 /* 104 * This replaces "zs_reset()" in the sparc driver. 105 */ 106 static void 107 zs_setparam(cs, iena, rate) 108 struct zs_chanstate *cs; 109 int iena; 110 int rate; 111 { 112 int s, tconst; 113 114 bcopy(zs_kgdb_regs, cs->cs_preg, 16); 115 116 if (iena) { 117 cs->cs_preg[1] = ZSWR1_RIE | ZSWR1_SIE; 118 } 119 120 /* Initialize the speed, etc. */ 121 tconst = BPS_TO_TCONST(cs->cs_brg_clk, rate); 122 cs->cs_preg[5] |= ZSWR5_DTR | ZSWR5_RTS; 123 cs->cs_preg[12] = tconst; 124 cs->cs_preg[13] = tconst >> 8; 125 126 s = splhigh(); 127 zs_loadchannelregs(cs); 128 splx(s); 129 } 130 131 /* 132 * Set up for kgdb; called at boot time before configuration. 133 * KGDB interrupts will be enabled later when zs0 is configured. 134 * Called after cninit(), so printf() etc. works. 135 */ 136 void 137 zs_kgdb_init() 138 { 139 struct zs_chanstate cs; 140 volatile struct zschan *zc; 141 int channel, zs_unit; 142 143 printf("zs_kgdb_init: kgdb_dev=0x%x\n", kgdb_dev); 144 if (major(kgdb_dev) != zs_major) 145 return; 146 147 /* Note: (ttya,ttyb) on zs0, and (ttyc,ttyd) on zs2 */ 148 zs_unit = (kgdb_dev & 2) ? 2 : 0; /* XXX - config info! */ 149 channel = kgdb_dev & 1; 150 printf("zs_kgdb_init: attaching tty%c at %d baud\n", 151 'a' + (kgdb_dev & 3), kgdb_rate); 152 153 /* Setup temporary chanstate. */ 154 bzero((caddr_t)&cs, sizeof(cs)); 155 zc = zs_get_chan_addr(zs_unit, channel); 156 157 if (zc == NULL) { 158 printf("zs_kgdb_init: zs not mapped.\n"); 159 kgdb_dev = -1; 160 return; 161 } 162 163 cs.cs_channel = channel; 164 cs.cs_brg_clk = PCLK / 16; 165 cs.cs_reg_csr = &zc->zc_csr; 166 cs.cs_reg_data = &zc->zc_data; 167 168 /* Now set parameters. (interrupts disabled) */ 169 zs_setparam(&cs, 0, kgdb_rate); 170 171 /* Store the getc/putc functions and arg. */ 172 kgdb_attach(zs_getc, zs_putc, (void *)zc); 173 } 174 175 /* 176 * This is a "hook" called by zstty_attach to allow the tty 177 * to be "taken over" for exclusive use by kgdb. 178 * Return non-zero if this is the kgdb port. 179 * 180 * Set the speed to kgdb_rate, CS8, etc. 181 */ 182 int 183 zs_check_kgdb(cs, dev) 184 struct zs_chanstate *cs; 185 int dev; 186 { 187 188 if (dev != kgdb_dev) 189 return (0); 190 191 /* 192 * Yes, this is port in use by kgdb. 193 */ 194 cs->cs_private = NULL; 195 cs->cs_ops = &zsops_kgdb; 196 197 /* Now set parameters. (interrupts enabled) */ 198 zs_setparam(cs, 1, kgdb_rate); 199 200 return (1); 201 } 202 203 /* 204 * KGDB framing character received: enter kernel debugger. This probably 205 * should time out after a few seconds to avoid hanging on spurious input. 206 */ 207 void 208 zskgdb(cs) 209 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 __P((struct zs_chanstate *)); 224 static void zs_kgdb_stint __P((struct zs_chanstate *, int)); 225 static void zs_kgdb_txint __P((struct zs_chanstate *)); 226 static void zs_kgdb_softint __P((struct zs_chanstate *)); 227 228 int kgdb_input_lost; 229 230 static void 231 zs_kgdb_rxint(cs) 232 struct zs_chanstate *cs; 233 { 234 register u_char c, rr1; 235 236 /* 237 * First read the status, because reading the received char 238 * destroys the status of this char. 239 */ 240 rr1 = zs_read_reg(cs, 1); 241 c = zs_read_data(cs); 242 243 if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) { 244 /* Clear the receive error. */ 245 zs_write_csr(cs, ZSWR0_RESET_ERRORS); 246 } 247 248 if (c == KGDB_START) { 249 zskgdb(cs); 250 } else { 251 kgdb_input_lost++; 252 } 253 } 254 255 static void 256 zs_kgdb_txint(cs) 257 register struct zs_chanstate *cs; 258 { 259 register int rr0; 260 261 rr0 = zs_read_csr(cs); 262 zs_write_csr(cs, ZSWR0_RESET_TXINT); 263 } 264 265 static void 266 zs_kgdb_stint(cs, force) 267 register struct zs_chanstate *cs; 268 int force; 269 { 270 register int rr0; 271 272 rr0 = zs_read_csr(cs); 273 zs_write_csr(cs, ZSWR0_RESET_STATUS); 274 275 /* 276 * Check here for console break, so that we can abort 277 * even when interrupts are locking up the machine. 278 */ 279 if (rr0 & ZSRR0_BREAK) { 280 zskgdb(cs); 281 } 282 } 283 284 static void 285 zs_kgdb_softint(cs) 286 struct zs_chanstate *cs; 287 { 288 printf("zs_kgdb_softint?\n"); 289 } 290 291 struct zsops zsops_kgdb = { 292 zs_kgdb_rxint, /* receive char available */ 293 zs_kgdb_stint, /* external/status */ 294 zs_kgdb_txint, /* xmit buffer empty */ 295 zs_kgdb_softint, /* process software interrupt */ 296 }; 297