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db_memrw.c revision 1.7 
      1 /*	$NetBSD: db_memrw.c,v 1.7 1995/02/07 04:37:48 gwr Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1994, 1995 Gordon W. Ross
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. The name of the author may not be used to endorse or promote products
     16  *    derived from this software without specific prior written permission.
     17  * 4. All advertising materials mentioning features or use of this software
     18  *    must display the following acknowledgement:
     19  *      This product includes software developed by Gordon Ross
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 /*
     34  * Machine-dependent functions used by ddb
     35  */
     36 
     37 #include <sys/param.h>
     38 #include <sys/proc.h>
     39 
     40 #include <vm/vm.h>
     41 
     42 #include <machine/db_machdep.h>
     43 #include <ddb/db_command.h>
     44 
     45 #include <machine/pte.h>
     46 
     47 /*
     48  * Interface to the debugger for virtual memory read/write.
     49  *
     50  * To write in the text segment, we have to first make
     51  * the page writable, do the write, then restore the PTE.
     52  * For writes outside the text segment, and all reads,
     53  * just do the access -- if it causes a fault, the debugger
     54  * will recover with a longjmp to an appropriate place.
     55  */
     56 
     57 /*
     58  * Read bytes from kernel address space for debugger.
     59  * This used to check for valid PTEs, but now that
     60  * traps in DDB work correctly, "Just Do It!"
     61  */
     62 void
     63 db_read_bytes(addr, size, data)
     64 	vm_offset_t	addr;
     65 	register int	size;
     66 	register char	*data;
     67 {
     68 	register char	*src;
     69 
     70 	src = (char *)addr;
     71 	while (--size >= 0)
     72 		*data++ = *src++;
     73 }
     74 
     75 /*
     76  * Write one byte somewhere in kernel text.
     77  * It does not matter if this is slow. -gwr
     78  */
     79 static void
     80 db_write_text(dst, ch)
     81 	char *dst;
     82 	int ch;
     83 {
     84 	int		oldpte, tmppte;
     85 	vm_offset_t pgva;
     86 
     87 	pgva = sun3_trunc_page((long)dst);
     88 	oldpte = get_pte(pgva);
     89 
     90 	if ((oldpte & PG_VALID) == 0) {
     91 		db_printf(" address 0x%x not a valid page\n", dst);
     92 		return;
     93 	}
     94 
     95 	tmppte = oldpte | PG_WRITE;
     96 	set_pte(pgva, tmppte);
     97 
     98 	*dst = (char) ch;
     99 
    100 	set_pte(pgva, oldpte);
    101 }
    102 
    103 /*
    104  * Write bytes to kernel address space for debugger.
    105  */
    106 void
    107 db_write_bytes(addr, size, data)
    108 	vm_offset_t	addr;
    109 	int	size;
    110 	char	*data;
    111 {
    112 	extern char	start[], etext[] ;
    113 	char	*dst;
    114 
    115 	dst = (char *)addr;
    116 	while (--size >= 0) {
    117 		if ((dst >= start) && (dst < etext))
    118 			db_write_text(dst, *data);
    119 		else
    120 			*dst = *data;
    121 		dst++; data++;
    122 	}
    123 }
    124 
    125 
    126 /*
    127  * Machine-specific ddb commands for the sun3:
    128  *    abort:	Drop into monitor via abort (allows continue)
    129  *    halt: 	Exit to monitor as in halt(8)
    130  *    reboot:	Reboot the machine as in reboot(8)
    131  */
    132 
    133 extern void sun3_mon_abort();
    134 extern void sun3_mon_halt();
    135 
    136 void
    137 db_mon_reboot()
    138 {
    139 	sun3_mon_reboot("");
    140 }
    141 
    142 struct db_command db_machine_cmds[] = {
    143 	{ "abort",	sun3_mon_abort,	0,	0 },
    144 	{ "halt",	sun3_mon_halt,	0,	0 },
    145 	{ "reboot",	db_mon_reboot,	0,	0 },
    146 	{ (char *)0, }
    147 };
    148 
    149 /*
    150  * This is called before ddb_init() to install the
    151  * machine-specific command table. (see machdep.c)
    152  */
    153 void
    154 db_machine_init()
    155 {
    156 	db_machine_commands_install(db_machine_cmds);
    157 }
    158