1 /* $NetBSD: zs_kgdb.c,v 1.12 2008/04/28 20:23:30 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 1.12 2008/04/28 20:23:30 martin Exp $"); 45 46 #include "opt_kgdb.h" 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/proc.h> 51 #include <sys/device.h> 52 #include <sys/conf.h> 53 #include <sys/ioctl.h> 54 #include <sys/kernel.h> 55 #include <sys/syslog.h> 56 #include <sys/kgdb.h> 57 58 #include <machine/cpu.h> 59 60 #include <dev/ic/z8530reg.h> 61 #include <machine/z8530var.h> 62 #include <next68k/dev/zs_cons.h> 63 64 /* 65 * The NeXT provides a 3.686400 MHz clock to the ZS chips. 66 */ 67 #define PCLK (9600 * 384) /* PCLK pin input clock rate */ 68 69 /* The layout of this is hardware-dependent (padding, order). */ 70 struct zschan { 71 volatile uint8_t zc_csr; /* ctrl,status, and indirect access */ 72 uint8_t zc_xxx0; 73 volatile uint8_t zc_data; /* data */ 74 uint8_t zc_xxx1; 75 }; 76 77 static void zs_setparam(struct zs_chanstate *, int, int); 78 struct zsops zsops_kgdb; 79 80 static uint8_t zs_kgdb_regs[16] = { 81 0, /* 0: CMD (reset, etc.) */ 82 0, /* 1: No interrupts yet. */ 83 0x18 + NEXT_I_IPL(NEXT_I_SCC), /* 2: IVECT */ 84 ZSWR3_RX_8 | ZSWR3_RX_ENABLE, 85 ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP, 86 ZSWR5_TX_8 | ZSWR5_TX_ENABLE, 87 0, /* 6: TXSYNC/SYNCLO */ 88 0, /* 7: RXSYNC/SYNCHI */ 89 0, /* 8: alias for data port */ 90 ZSWR9_MASTER_IE, 91 0, /*10: Misc. TX/RX control bits */ 92 ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD, 93 ((PCLK/32)/9600)-2, /*12: BAUDLO (default=9600) */ 94 0, /*13: BAUDHI (default=9600) */ 95 ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK, 96 ZSWR15_BREAK_IE, 97 }; 98 99 /* 100 * This replaces "zs_reset()" in the sparc driver. 101 */ 102 static void 103 zs_setparam(struct zs_chanstate *cs, int iena, int rate) 104 { 105 int s, tconst; 106 107 memcpy(cs->cs_preg, zs_kgdb_regs, 16); 108 109 if (iena) { 110 cs->cs_preg[1] = ZSWR1_RIE | ZSWR1_SIE; 111 } 112 113 /* Initialize the speed, etc. */ 114 tconst = BPS_TO_TCONST(cs->cs_brg_clk, rate); 115 cs->cs_preg[5] |= ZSWR5_DTR | ZSWR5_RTS; 116 cs->cs_preg[12] = tconst; 117 cs->cs_preg[13] = tconst >> 8; 118 119 s = splhigh(); 120 zs_loadchannelregs(cs); 121 splx(s); 122 } 123 124 /* 125 * Set up for kgdb; called at boot time before configuration. 126 * KGDB interrupts will be enabled later when zs0 is configured. 127 * Called after cninit(), so printf() etc. works. 128 */ 129 void 130 zs_kgdb_init(void) 131 { 132 struct zs_chanstate cs; 133 volatile struct zschan *zc; 134 int channel; 135 extern const struct cdevsw zstty_cdevsw; 136 137 printf("zs_kgdb_init: kgdb_dev=0x%x\n", kgdb_dev); 138 if (cdevsw_lookup(kgdb_dev) != &zstty_cdevsw) 139 return; 140 141 /* Note: (ttya,ttyb) on zs0, and (ttyc,ttyd) on zs2 */ 142 channel = kgdb_dev & 1; 143 printf("zs_kgdb_init: attaching tty%c at %d baud\n", 144 'a' + (kgdb_dev & 3), kgdb_rate); 145 146 /* Setup temporary chanstate. */ 147 memset(&cs, 0, sizeof(cs)); 148 zc = zs_get_chan_addr(channel); 149 150 if (zc == NULL) { 151 printf("zs_kgdb_init: zs not mapped.\n"); 152 kgdb_dev = -1; 153 return; 154 } 155 156 cs.cs_channel = channel; 157 cs.cs_brg_clk = PCLK / 16; 158 cs.cs_reg_csr = &zc->zc_csr; 159 cs.cs_reg_data = &zc->zc_data; 160 161 /* Now set parameters. (interrupts disabled) */ 162 zs_setparam(&cs, 0, kgdb_rate); 163 164 /* Store the getc/putc functions and arg. */ 165 kgdb_attach(zs_getc, zs_putc, __UNVOLATILE(zc)); 166 } 167 168 /* 169 * This is a "hook" called by zstty_attach to allow the tty 170 * to be "taken over" for exclusive use by kgdb. 171 * Return non-zero if this is the kgdb port. 172 * 173 * Set the speed to kgdb_rate, CS8, etc. 174 */ 175 int 176 zs_check_kgdb(struct zs_chanstate *cs, int dev) 177 { 178 179 if (dev != kgdb_dev) 180 return (0); 181 182 /* 183 * Yes, this is port in use by kgdb. 184 */ 185 cs->cs_private = NULL; 186 cs->cs_ops = &zsops_kgdb; 187 188 /* Now set parameters. (interrupts enabled) */ 189 zs_setparam(cs, 1, kgdb_rate); 190 191 return (1); 192 } 193 194 /* 195 * KGDB framing character received: enter kernel debugger. This probably 196 * should time out after a few seconds to avoid hanging on spurious input. 197 */ 198 void 199 zskgdb(struct zs_chanstate *cs) 200 { 201 int unit = minor(kgdb_dev); 202 203 printf("zstty%d: kgdb interrupt\n", unit); 204 /* This will trap into the debugger. */ 205 kgdb_connect(1); 206 } 207 208 209 /**************************************************************** 210 * Interface to the lower layer (zscc) 211 ****************************************************************/ 212 213 static void zs_kgdb_rxint(struct zs_chanstate *); 214 static void zs_kgdb_stint(struct zs_chanstate *, int); 215 static void zs_kgdb_txint(struct zs_chanstate *); 216 static void zs_kgdb_softint(struct zs_chanstate *); 217 218 int kgdb_input_lost; 219 220 static void 221 zs_kgdb_rxint(struct zs_chanstate *cs) 222 { 223 uint8_t c, rr1; 224 225 /* 226 * First read the status, because reading the received char 227 * destroys the status of this char. 228 */ 229 rr1 = zs_read_reg(cs, 1); 230 c = zs_read_data(cs); 231 232 if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) { 233 /* Clear the receive error. */ 234 zs_write_csr(cs, ZSWR0_RESET_ERRORS); 235 } 236 237 if (c == KGDB_START) { 238 zskgdb(cs); 239 } else { 240 kgdb_input_lost++; 241 } 242 } 243 244 static void 245 zs_kgdb_txint(struct zs_chanstate *cs) 246 { 247 int rr0; 248 249 rr0 = zs_read_csr(cs); 250 zs_write_csr(cs, ZSWR0_RESET_TXINT); 251 } 252 253 static void 254 zs_kgdb_stint(struct zs_chanstate *cs, int force) 255 { 256 int rr0; 257 258 rr0 = zs_read_csr(cs); 259 zs_write_csr(cs, ZSWR0_RESET_STATUS); 260 261 /* 262 * Check here for console break, so that we can abort 263 * even when interrupts are locking up the machine. 264 */ 265 if (rr0 & ZSRR0_BREAK) { 266 zskgdb(cs); 267 } 268 } 269 270 static void 271 zs_kgdb_softint(struct zs_chanstate *cs) 272 { 273 printf("zs_kgdb_softint?\n"); 274 } 275 276 struct zsops zsops_kgdb = { 277 zs_kgdb_rxint, /* receive char available */ 278 zs_kgdb_stint, /* external/status */ 279 zs_kgdb_txint, /* xmit buffer empty */ 280 zs_kgdb_softint, /* process software interrupt */ 281 }; 282