1 /* $NetBSD: zs_kgdb.c,v 1.24 2007/10/17 19:57:45 garbled 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 1.24 2007/10/17 19:57:45 garbled Exp $"); 52 53 #include "opt_kgdb.h" 54 55 #include <sys/param.h> 56 #include <sys/systm.h> 57 #include <sys/proc.h> 58 #include <sys/device.h> 59 #include <sys/conf.h> 60 #include <sys/ioctl.h> 61 #include <sys/kernel.h> 62 #include <sys/syslog.h> 63 #include <sys/kgdb.h> 64 65 #include <dev/ic/z8530reg.h> 66 #include <machine/z8530var.h> 67 #include <sun3/dev/zs_cons.h> 68 69 /* The Sun3 provides a 4.9152 MHz clock to the ZS chips. */ 70 #define PCLK (9600 * 512) /* PCLK pin input clock rate */ 71 #define ZSHARD_PRI 6 /* Wired on the CPU board... */ 72 73 #define ZS_DELAY() delay(2) 74 75 /* The layout of this is hardware-dependent (padding, order). */ 76 struct zschan { 77 volatile u_char zc_csr; /* ctrl,status, and indirect access */ 78 u_char zc_xxx0; 79 volatile u_char zc_data; /* data */ 80 u_char zc_xxx1; 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 struct zschan *zc; 142 int channel, zsc_unit; 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 zsc_unit = (kgdb_dev & 2) ? 0 : 1; 151 channel = kgdb_dev & 1; 152 printf("zs_kgdb_init: attaching tty%c at %d baud\n", 153 'a' + (kgdb_dev & 3), kgdb_rate); 154 155 /* Setup temporary chanstate. */ 156 memset((void *)&cs, 0, sizeof(cs)); 157 zc = zs_get_chan_addr(zsc_unit, channel); 158 if (zc == NULL) { 159 printf("zs_kgdb_init: zs not mapped.\n"); 160 kgdb_dev = -1; 161 return; 162 } 163 164 cs.cs_channel = channel; 165 cs.cs_brg_clk = PCLK / 16; 166 cs.cs_reg_csr = &zc->zc_csr; 167 cs.cs_reg_data = &zc->zc_data; 168 169 /* Now set parameters. (interrupts disabled) */ 170 zs_setparam(&cs, 0, kgdb_rate); 171 172 /* Store the getc/putc functions and arg. */ 173 kgdb_attach(zs_getc, zs_putc, __UNVOLATILE(zc)); 174 } 175 176 /* 177 * This is a "hook" called by zstty_attach to allow the tty 178 * to be "taken over" for exclusive use by kgdb. 179 * Return non-zero if this is the kgdb port. 180 * 181 * Set the speed to kgdb_rate, CS8, etc. 182 */ 183 int 184 zs_check_kgdb(struct zs_chanstate *cs, int dev) 185 { 186 187 if (dev != kgdb_dev) 188 return (0); 189 190 /* 191 * Yes, this is port in use by kgdb. 192 */ 193 cs->cs_private = NULL; 194 cs->cs_ops = &zsops_kgdb; 195 196 /* Now set parameters. (interrupts enabled) */ 197 zs_setparam(cs, 1, kgdb_rate); 198 199 return (1); 200 } 201 202 /* 203 * KGDB framing character received: enter kernel debugger. This probably 204 * should time out after a few seconds to avoid hanging on spurious input. 205 */ 206 static void 207 zskgdb(struct zs_chanstate *cs) 208 { 209 int unit = minor(kgdb_dev); 210 211 printf("zstty%d: kgdb interrupt\n", unit); 212 /* This will trap into the debugger. */ 213 kgdb_connect(1); 214 } 215 216 217 /**************************************************************** 218 * Interface to the lower layer (zscc) 219 ****************************************************************/ 220 221 static void zs_kgdb_rxint(struct zs_chanstate *); 222 static void zs_kgdb_stint(struct zs_chanstate *, int); 223 static void zs_kgdb_txint(struct zs_chanstate *); 224 static void zs_kgdb_softint(struct zs_chanstate *); 225 226 int kgdb_input_lost; 227 228 static void 229 zs_kgdb_rxint(struct zs_chanstate *cs) 230 { 231 u_char c, rr1; 232 233 /* 234 * First read the status, because reading the received char 235 * destroys the status of this char. 236 */ 237 rr1 = zs_read_reg(cs, 1); 238 c = zs_read_data(cs); 239 240 if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) { 241 /* Clear the receive error. */ 242 zs_write_csr(cs, ZSWR0_RESET_ERRORS); 243 } 244 245 if (c == KGDB_START) { 246 zskgdb(cs); 247 } else { 248 kgdb_input_lost++; 249 } 250 } 251 252 static void 253 zs_kgdb_txint(struct zs_chanstate *cs) 254 { 255 int rr0; 256 257 rr0 = zs_read_csr(cs); 258 zs_write_csr(cs, ZSWR0_RESET_TXINT); 259 } 260 261 static void 262 zs_kgdb_stint(struct zs_chanstate *cs, int force) 263 { 264 int rr0; 265 266 rr0 = zs_read_csr(cs); 267 zs_write_csr(cs, ZSWR0_RESET_STATUS); 268 269 /* 270 * Check here for console break, so that we can abort 271 * even when interrupts are locking up the machine. 272 */ 273 if (rr0 & ZSRR0_BREAK) { 274 zskgdb(cs); 275 } 276 } 277 278 static void 279 zs_kgdb_softint(struct zs_chanstate *cs) 280 { 281 printf("zs_kgdb_softint?\n"); 282 } 283 284 struct zsops zsops_kgdb = { 285 zs_kgdb_rxint, /* receive char available */ 286 zs_kgdb_stint, /* external/status */ 287 zs_kgdb_txint, /* xmit buffer empty */ 288 zs_kgdb_softint, /* process software interrupt */ 289 }; 290