1 /* $NetBSD: zs_kgdb.c,v 1.8 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 1.8 2008/04/28 20:23:27 martin Exp $"); 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/proc.h> 49 #include <sys/device.h> 50 #include <sys/conf.h> 51 #include <sys/ioctl.h> 52 #include <sys/kernel.h> 53 #include <sys/syslog.h> 54 #include <sys/kgdb.h> 55 56 #include <dev/ofw/openfirm.h> 57 #include <dev/ic/z8530reg.h> 58 #include <machine/z8530var.h> 59 60 static void zs_setparam __P((struct zs_chanstate *, int, int)); 61 static void zskgdb __P((struct zs_chanstate *)); 62 63 struct zsops zsops_kgdb; 64 65 static u_char zs_kgdb_regs[16] = { 66 0, /* 0: CMD (reset, etc.) */ 67 0, /* 1: ~(ZSWR1_RIE | ZSWR1_TIE | ZSWR1_SIE) */ 68 0, /* IVECT */ 69 ZSWR3_RX_8 | ZSWR3_RX_ENABLE, 70 ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP, 71 ZSWR5_TX_8 | ZSWR5_TX_ENABLE, 72 0, /* 6: TXSYNC/SYNCLO */ 73 0, /* 7: RXSYNC/SYNCHI */ 74 0, /* 8: alias for data port */ 75 ZSWR9_MASTER_IE, 76 0, /*10: Misc. TX/RX control bits */ 77 ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD, 78 ((PCLK/32)/38400)-2, /*12: BAUDLO (default=38400) */ 79 0, /*13: BAUDHI (default=38400) */ 80 ZSWR14_BAUD_ENA, 81 ZSWR15_BREAK_IE, 82 }; 83 84 /* 85 * This replaces "zs_reset()" in the sparc driver. 86 */ 87 static void 88 zs_setparam(cs, iena, rate) 89 struct zs_chanstate *cs; 90 int iena; 91 int rate; 92 { 93 int s, tconst; 94 95 bcopy(zs_kgdb_regs, cs->cs_preg, 16); 96 97 if (iena) { 98 cs->cs_preg[1] = ZSWR1_RIE | ZSWR1_SIE; 99 } 100 101 /* Initialize the speed, etc. */ 102 tconst = BPS_TO_TCONST(cs->cs_brg_clk, rate); 103 cs->cs_preg[5] |= ZSWR5_DTR | ZSWR5_RTS; 104 cs->cs_preg[12] = tconst; 105 cs->cs_preg[13] = tconst >> 8; 106 107 s = splhigh(); 108 zs_loadchannelregs(cs); 109 splx(s); 110 } 111 112 #ifndef KGDB_DEVNAME 113 #define KGDB_DEVNAME "scca" 114 #endif 115 char *zs_kgdb_devname = KGDB_DEVNAME; 116 /* 117 * Set up for kgdb; called at boot time before configuration. 118 * KGDB interrupts will be enabled later when zs0 is configured. 119 * Called after cninit(), so printf() etc. works. 120 */ 121 void 122 zs_kgdb_init() 123 { 124 extern const struct cdevsw zstty_cdevsw; 125 struct zs_chanstate cs; 126 volatile struct zschan *zc; 127 int escc, escc_ch, obio, zs_offset; 128 int channel = 0; 129 u_int32_t reg[5]; 130 char name[16]; 131 132 if ((escc_ch = OF_finddevice(zs_kgdb_devname)) == -1) 133 return; 134 135 memset(name, 0, sizeof(name)); 136 if (OF_getprop(escc_ch, "device_type", name, sizeof(name)) == -1) 137 return; 138 139 if (strcmp(name, "serial") != 0) 140 return; 141 142 memset(name, 0, sizeof(name)); 143 if (OF_getprop(escc_ch, "name", name, sizeof(name)) == -1) 144 return; 145 146 if (strcmp(name, "ch-b") == 0) 147 channel = 1; 148 149 if (OF_getprop(escc_ch, "reg", reg, sizeof(reg)) < 4) 150 return; 151 zs_offset = reg[0]; 152 153 escc = OF_parent(escc_ch); 154 obio = OF_parent(escc); 155 156 if (OF_getprop(obio, "assigned-addresses", reg, sizeof(reg)) < 12) 157 return; 158 zc = (struct zschan *)(reg[2] + zs_offset); 159 160 kgdb_dev = makedev(cdevsw_lookup_major(&zstty_cdevsw), channel); 161 162 printf("zs_kgdb_init: attaching tty%02d at %d baud\n", 163 channel, kgdb_rate); 164 165 /* Setup temporary chanstate. */ 166 bzero((void *)&cs, sizeof(cs)); 167 cs.cs_channel = channel; 168 cs.cs_brg_clk = PCLK / 16; 169 cs.cs_reg_csr = &zc->zc_csr; 170 cs.cs_reg_data = &zc->zc_data; 171 172 /* Now set parameters. (interrupts disabled) */ 173 zs_setparam(&cs, 0, kgdb_rate); 174 175 /* Store the getc/putc functions and arg. */ 176 kgdb_attach(zs_getc, zs_putc, __UNVOLATILE(zc)); 177 } 178 179 /* 180 * This is a "hook" called by zstty_attach to allow the tty 181 * to be "taken over" for exclusive use by kgdb. 182 * Return non-zero if this is the kgdb port. 183 * 184 * Set the speed to kgdb_rate, CS8, etc. 185 */ 186 int 187 zs_check_kgdb(cs, dev) 188 struct zs_chanstate *cs; 189 int dev; 190 { 191 192 if (dev != kgdb_dev) 193 return (0); 194 195 /* 196 * Yes, this is port in use by kgdb. 197 */ 198 cs->cs_private = NULL; 199 cs->cs_ops = &zsops_kgdb; 200 201 /* Now set parameters. (interrupts enabled) */ 202 zs_setparam(cs, 1, kgdb_rate); 203 204 return (1); 205 } 206 207 /* 208 * KGDB framing character received: enter kernel debugger. This probably 209 * should time out after a few seconds to avoid hanging on spurious input. 210 */ 211 static void 212 zskgdb(cs) 213 struct zs_chanstate *cs; 214 { 215 int unit = minor(kgdb_dev); 216 217 printf("zstty%d: kgdb interrupt\n", unit); 218 /* This will trap into the debugger. */ 219 kgdb_connect(1); 220 } 221 222 223 /**************************************************************** 224 * Interface to the lower layer (zscc) 225 ****************************************************************/ 226 227 static void zs_kgdb_rxint __P((struct zs_chanstate *)); 228 static void zs_kgdb_stint __P((struct zs_chanstate *, int)); 229 static void zs_kgdb_txint __P((struct zs_chanstate *)); 230 static void zs_kgdb_softint __P((struct zs_chanstate *)); 231 232 int kgdb_input_lost; 233 234 static void 235 zs_kgdb_rxint(cs) 236 struct zs_chanstate *cs; 237 { 238 register u_char c, rr1; 239 240 /* 241 * First read the status, because reading the received char 242 * destroys the status of this char. 243 */ 244 rr1 = zs_read_reg(cs, 1); 245 c = zs_read_data(cs); 246 247 if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) { 248 /* Clear the receive error. */ 249 zs_write_csr(cs, ZSWR0_RESET_ERRORS); 250 } 251 252 if (c == KGDB_START) { 253 zskgdb(cs); 254 } else { 255 kgdb_input_lost++; 256 } 257 } 258 259 static void 260 zs_kgdb_txint(cs) 261 register struct zs_chanstate *cs; 262 { 263 register int rr0; 264 265 rr0 = zs_read_csr(cs); 266 zs_write_csr(cs, ZSWR0_RESET_TXINT); 267 } 268 269 static void 270 zs_kgdb_stint(cs, force) 271 register struct zs_chanstate *cs; 272 int force; 273 { 274 register int rr0; 275 276 rr0 = zs_read_csr(cs); 277 zs_write_csr(cs, ZSWR0_RESET_STATUS); 278 279 /* 280 * Check here for console break, so that we can abort 281 * even when interrupts are locking up the machine. 282 */ 283 if (rr0 & ZSRR0_BREAK) { 284 zskgdb(cs); 285 } 286 } 287 288 static void 289 zs_kgdb_softint(cs) 290 struct zs_chanstate *cs; 291 { 292 printf("zs_kgdb_softint?\n"); 293 } 294 295 struct zsops zsops_kgdb = { 296 zs_kgdb_rxint, /* receive char available */ 297 zs_kgdb_stint, /* external/status */ 298 zs_kgdb_txint, /* xmit buffer empty */ 299 zs_kgdb_softint, /* process software interrupt */ 300 }; 301