1 /* $NetBSD: zs_kgdb.c,v 1.10 2007/10/17 19:56:04 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 1.10 2007/10/17 19:56:04 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 <machine/cpu.h> 66 67 #include <dev/ic/z8530reg.h> 68 #include <machine/z8530var.h> 69 #include <next68k/dev/zs_cons.h> 70 71 /* 72 * The NeXT provides a 3.686400 MHz clock to the ZS chips. 73 */ 74 #define PCLK (9600 * 384) /* PCLK pin input clock rate */ 75 76 /* The layout of this is hardware-dependent (padding, order). */ 77 struct zschan { 78 volatile u_char zc_csr; /* ctrl,status, and indirect access */ 79 u_char zc_xxx0; 80 volatile u_char zc_data; /* data */ 81 u_char zc_xxx1; 82 }; 83 84 static void zs_setparam(struct zs_chanstate *, int, int); 85 struct zsops zsops_kgdb; 86 87 static u_char zs_kgdb_regs[16] = { 88 0, /* 0: CMD (reset, etc.) */ 89 0, /* 1: No interrupts yet. */ 90 0x18 + NEXT_I_IPL(NEXT_I_SCC), /* 2: IVECT */ 91 ZSWR3_RX_8 | ZSWR3_RX_ENABLE, 92 ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP, 93 ZSWR5_TX_8 | ZSWR5_TX_ENABLE, 94 0, /* 6: TXSYNC/SYNCLO */ 95 0, /* 7: RXSYNC/SYNCHI */ 96 0, /* 8: alias for data port */ 97 ZSWR9_MASTER_IE, 98 0, /*10: Misc. TX/RX control bits */ 99 ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD, 100 ((PCLK/32)/9600)-2, /*12: BAUDLO (default=9600) */ 101 0, /*13: BAUDHI (default=9600) */ 102 ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK, 103 ZSWR15_BREAK_IE, 104 }; 105 106 /* 107 * This replaces "zs_reset()" in the sparc driver. 108 */ 109 static void 110 zs_setparam(struct zs_chanstate *cs, int iena, int rate) 111 { 112 int s, tconst; 113 114 memcpy(cs->cs_preg, zs_kgdb_regs, 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(void) 138 { 139 struct zs_chanstate cs; 140 volatile struct zschan *zc; 141 int channel; 142 extern const struct cdevsw zstty_cdevsw; 143 144 printf("zs_kgdb_init: kgdb_dev=0x%x\n", kgdb_dev); 145 if (cdevsw_lookup(kgdb_dev) != &zstty_cdevsw) 146 return; 147 148 /* Note: (ttya,ttyb) on zs0, and (ttyc,ttyd) on zs2 */ 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 memset(&cs, 0, sizeof(cs)); 155 zc = zs_get_chan_addr(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, __UNVOLATILE(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(struct zs_chanstate *cs, int dev) 184 { 185 186 if (dev != kgdb_dev) 187 return (0); 188 189 /* 190 * Yes, this is port in use by kgdb. 191 */ 192 cs->cs_private = NULL; 193 cs->cs_ops = &zsops_kgdb; 194 195 /* Now set parameters. (interrupts enabled) */ 196 zs_setparam(cs, 1, kgdb_rate); 197 198 return (1); 199 } 200 201 /* 202 * KGDB framing character received: enter kernel debugger. This probably 203 * should time out after a few seconds to avoid hanging on spurious input. 204 */ 205 void 206 zskgdb(struct zs_chanstate *cs) 207 { 208 int unit = minor(kgdb_dev); 209 210 printf("zstty%d: kgdb interrupt\n", unit); 211 /* This will trap into the debugger. */ 212 kgdb_connect(1); 213 } 214 215 216 /**************************************************************** 217 * Interface to the lower layer (zscc) 218 ****************************************************************/ 219 220 static void zs_kgdb_rxint(struct zs_chanstate *); 221 static void zs_kgdb_stint(struct zs_chanstate *, int); 222 static void zs_kgdb_txint(struct zs_chanstate *); 223 static void zs_kgdb_softint(struct zs_chanstate *); 224 225 int kgdb_input_lost; 226 227 static void 228 zs_kgdb_rxint(struct zs_chanstate *cs) 229 { 230 u_char c, rr1; 231 232 /* 233 * First read the status, because reading the received char 234 * destroys the status of this char. 235 */ 236 rr1 = zs_read_reg(cs, 1); 237 c = zs_read_data(cs); 238 239 if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) { 240 /* Clear the receive error. */ 241 zs_write_csr(cs, ZSWR0_RESET_ERRORS); 242 } 243 244 if (c == KGDB_START) { 245 zskgdb(cs); 246 } else { 247 kgdb_input_lost++; 248 } 249 } 250 251 static void 252 zs_kgdb_txint(struct zs_chanstate *cs) 253 { 254 int rr0; 255 256 rr0 = zs_read_csr(cs); 257 zs_write_csr(cs, ZSWR0_RESET_TXINT); 258 } 259 260 static void 261 zs_kgdb_stint(struct zs_chanstate *cs, int force) 262 { 263 int rr0; 264 265 rr0 = zs_read_csr(cs); 266 zs_write_csr(cs, ZSWR0_RESET_STATUS); 267 268 /* 269 * Check here for console break, so that we can abort 270 * even when interrupts are locking up the machine. 271 */ 272 if (rr0 & ZSRR0_BREAK) { 273 zskgdb(cs); 274 } 275 } 276 277 static void 278 zs_kgdb_softint(struct zs_chanstate *cs) 279 { 280 printf("zs_kgdb_softint?\n"); 281 } 282 283 struct zsops zsops_kgdb = { 284 zs_kgdb_rxint, /* receive char available */ 285 zs_kgdb_stint, /* external/status */ 286 zs_kgdb_txint, /* xmit buffer empty */ 287 zs_kgdb_softint, /* process software interrupt */ 288 }; 289