/* $NetBSD: zs_kgdb.c,v 1.12 2023/10/24 19:05:07 andvar Exp $ */ /*- * Copyright (c) 1996 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Gordon W. Ross. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /* * Hooks for kgdb when attached via the z8530 driver * * To use this, build a kernel with: option KGDB, and * boot that kernel with "-d". (The kernel will call * zs_kgdb_init, kgdb_connect.) When the console prints * "kgdb waiting..." you run "gdb -k kernel" and do: * (gdb) set remotebaud 19200 * (gdb) target remote /dev/ttyb */ #include <sys/cdefs.h> __KERNEL_RCSID(0, "$NetBSD: zs_kgdb.c,v 1.12 2023/10/24 19:05:07 andvar Exp $"); #include "opt_kgdb.h" #include <sys/param.h> #include <sys/systm.h> #include <sys/proc.h> #include <sys/device.h> #include <sys/conf.h> #include <sys/ioctl.h> #include <sys/kernel.h> #include <sys/syslog.h> #include <sys/kgdb.h> #include <dev/ic/z8530reg.h> #include <machine/z8530var.h> #include <mac68k/dev/zs_cons.h> /* * Macs supposely provide a 3.672 MHz clock to the SCC. Unfortunately, * empirical evidence suggests that it's really a 3.6864 MHz clock. * Oh, what to do, what to do?! */ #define PCLK (9600 * 384) /* PCLK pin input clock rate */ #define ZSHARD_PRI 4 /* Wired on the CPU board... */ #define ZS_DELAY() delay(2) /* The layout of this is hardware-dependent (padding, order). */ struct zschan { volatile u_char zc_csr; /* ctrl,status, and indirect access */ u_char zc_xxx0; u_char zc_xxx1; /* part of the other channel lives here! */ u_char zc_xxx2; /* Yea Apple! */ volatile u_char zc_data; /* data */ u_char zc_xxx3; u_char zc_xxx4; u_char zc_xxx5; }; static void zs_setparam(struct zs_chanstate *, int, int); static void zskgdb(struct zs_chanstate *); struct zsops zsops_kgdb; static u_char zs_kgdb_regs[16] = { 0, /* 0: CMD (reset, etc.) */ 0, /* 1: ~(ZSWR1_RIE | ZSWR1_TIE | ZSWR1_SIE) */ 0x18 + ZSHARD_PRI, /* IVECT */ ZSWR3_RX_8 | ZSWR3_RX_ENABLE, ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP, ZSWR5_TX_8 | ZSWR5_TX_ENABLE, 0, /* 6: TXSYNC/SYNCLO */ 0, /* 7: RXSYNC/SYNCHI */ 0, /* 8: alias for data port */ ZSWR9_MASTER_IE, 0, /*10: Misc. TX/RX control bits */ ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD, 14, /*12: BAUDLO (default=9600) */ 0, /*13: BAUDHI (default=9600) */ ZSWR14_BAUD_FROM_PCLK | ZSWR14_BAUD_ENA, ZSWR15_BREAK_IE, }; /* * This replaces "zs_reset()" in the sparc driver. */ static void zs_setparam(struct zs_chanstate *cs, int iena, int rate) { int s, tconst; memcpy(cs->cs_preg, zs_kgdb_regs, 16); if (iena) { cs->cs_preg[1] = ZSWR1_RIE | ZSWR1_SIE; } /* Initialize the speed, etc. */ tconst = BPS_TO_TCONST(cs->cs_brg_clk, rate); cs->cs_preg[5] |= ZSWR5_DTR | ZSWR5_RTS; cs->cs_preg[12] = tconst; cs->cs_preg[13] = tconst >> 8; s = splhigh(); zs_loadchannelregs(cs); splx(s); } /* * Set up for kgdb; called at boot time before configuration. * KGDB interrupts will be enabled later when zs0 is configured. * Called after cninit(), so printf() etc. works. */ void zs_kgdb_init(void) { struct zs_chanstate cs; volatile struct zschan *zc; int channel; extern const struct cdevsw zstty_cdevsw; /* printf("zs_kgdb_init: kgdb_dev=0x%x\n", kgdb_dev); */ if (cdevsw_lookup(kgdb_dev) != &zstty_cdevsw) return; /* Note: (ttya,ttyb) on zsc1, and (ttyc,ttyd) on zsc0 */ channel = kgdb_dev & 1; printf("zs_kgdb_init: attaching Serial(%lld) at %d baud\n", (kgdb_dev & 3), kgdb_rate); if (!zsinited) zs_init(); /* Setup temporary chanstate. */ memset(&cs, 0, sizeof(cs)); zc = zs_get_chan_addr(channel); if (zc == NULL) { printf("zs_kgdb_init: zs not mapped.\n"); kgdb_dev = -1; return; } cs.cs_channel = channel; cs.cs_brg_clk = PCLK / 16; cs.cs_reg_csr = &zc->zc_csr; cs.cs_reg_data = &zc->zc_data; /* Now set parameters. (interrupts disabled) */ zs_setparam(&cs, 0, kgdb_rate); /* Store the getc/putc functions and arg. */ kgdb_attach(zs_getc, zs_putc, __UNVOLATILE(zc)); } /* * This is a "hook" called by zstty_attach to allow the tty * to be "taken over" for exclusive use by kgdb. * Return non-zero if this is the kgdb port. * * Set the speed to kgdb_rate, CS8, etc. */ int zs_check_kgdb(struct zs_chanstate *cs, int dev) { if (dev != kgdb_dev) return (0); /* * Yes, this is port in use by kgdb. */ cs->cs_private = NULL; cs->cs_ops = &zsops_kgdb; /* Now set parameters. (interrupts enabled) */ zs_setparam(cs, 1, kgdb_rate); return (1); } /* * KGDB framing character received: enter kernel debugger. This probably * should time out after a few seconds to avoid hanging on spurious input. */ static void zskgdb(struct zs_chanstate *cs) { int unit = minor(kgdb_dev); printf("zstty%d: kgdb interrupt\n", unit); /* This will trap into the debugger. */ kgdb_connect(1); } /**************************************************************** * Interface to the lower layer (zscc) ****************************************************************/ static void zs_kgdb_rxint(struct zs_chanstate *); static void zs_kgdb_stint(struct zs_chanstate *, int); static void zs_kgdb_txint(struct zs_chanstate *); static void zs_kgdb_softint(struct zs_chanstate *); int kgdb_input_lost; static void zs_kgdb_rxint(struct zs_chanstate *cs) { u_char c, rr1; /* * First read the status, because reading the received char * destroys the status of this char. */ rr1 = zs_read_reg(cs, 1); c = zs_read_data(cs); if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) { /* Clear the receive error. */ zs_write_csr(cs, ZSWR0_RESET_ERRORS); } if (c == KGDB_START) { zskgdb(cs); } else { kgdb_input_lost++; } } static void zs_kgdb_txint(struct zs_chanstate *cs) { zs_write_csr(cs, ZSWR0_RESET_TXINT); } static void zs_kgdb_stint(struct zs_chanstate *cs, int force) { int rr0; rr0 = zs_read_csr(cs); zs_write_csr(cs, ZSWR0_RESET_STATUS); /* * Check here for console break, so that we can abort * even when interrupts are locking up the machine. */ if (rr0 & ZSRR0_BREAK) { zskgdb(cs); } } static void zs_kgdb_softint(struct zs_chanstate *cs) { printf("zs_kgdb_softint?\n"); } struct zsops zsops_kgdb = { zs_kgdb_rxint, /* receive char available */ zs_kgdb_stint, /* external/status */ zs_kgdb_txint, /* xmit buffer empty */ zs_kgdb_softint, /* process software interrupt */ };
