xref: /freebsd/sys/i386/include/db_machdep.h (revision 193d9e768ba63fcfb187cfd17f461f7d41345048)
1 /*-
2  * Mach Operating System
3  * Copyright (c) 1991,1990 Carnegie Mellon University
4  * All Rights Reserved.
5  *
6  * Permission to use, copy, modify and distribute this software and its
7  * documentation is hereby granted, provided that both the copyright
8  * notice and this permission notice appear in all copies of the
9  * software, derivative works or modified versions, and any portions
10  * thereof, and that both notices appear in supporting documentation.
11  *
12  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
13  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
14  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
15  *
16  * Carnegie Mellon requests users of this software to return to
17  *
18  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
19  *  School of Computer Science
20  *  Carnegie Mellon University
21  *  Pittsburgh PA 15213-3890
22  *
23  * any improvements or extensions that they make and grant Carnegie Mellon
24  * the rights to redistribute these changes.
25  *
26  * $FreeBSD$
27  */
28 
29 #ifndef _MACHINE_DB_MACHDEP_H_
30 #define	_MACHINE_DB_MACHDEP_H_
31 
32 #include <machine/frame.h>
33 #include <machine/trap.h>
34 
35 typedef	vm_offset_t	db_addr_t;	/* address - unsigned */
36 typedef	int		db_expr_t;	/* expression - signed */
37 
38 #define	PC_REGS()	((db_addr_t)(kdb_frame->tf_eflags & PSL_VM ?	\
39 			    (kdb_frame->tf_eip & 0xffff) +		\
40 			    ((kdb_frame->tf_cs & 0xffff) << 4) :	\
41 			    kdb_frame->tf_eip))
42 
43 #define	BKPT_INST	0xcc		/* breakpoint instruction */
44 #define	BKPT_SIZE	(1)		/* size of breakpoint inst */
45 #define	BKPT_SET(inst)	(BKPT_INST)
46 
47 #define BKPT_SKIP				\
48 do {						\
49 	kdb_frame->tf_eip += 1;			\
50 	kdb_thrctx->pcb_eip += 1;		\
51 } while(0)
52 
53 #define	FIXUP_PC_AFTER_BREAK			\
54 do {						\
55 	kdb_frame->tf_eip -= 1;			\
56 	kdb_thrctx->pcb_eip -= 1;		\
57 } while(0);
58 
59 #define	db_clear_single_step	kdb_cpu_clear_singlestep
60 #define	db_set_single_step	kdb_cpu_set_singlestep
61 
62 /*
63  * The debug exception type is copied from %dr6 to 'code' and used to
64  * disambiguate single step traps.  Watchpoints have no special support.
65  * Our hardware breakpoints are not well integrated with ddb and are too
66  * different from watchpoints.  ddb treats them as unknown traps with
67  * unknown addresses and doesn't turn them off while it is running.
68  */
69 #define	IS_BREAKPOINT_TRAP(type, code)	((type) == T_BPTFLT)
70 #define	IS_SSTEP_TRAP(type, code)	((type) == T_TRCTRAP && (code) & 0x4000)
71 #define	IS_WATCHPOINT_TRAP(type, code)	0
72 
73 #define	I_CALL		0xe8
74 #define	I_CALLI		0xff
75 #define	I_RET		0xc3
76 #define	I_IRET		0xcf
77 
78 #define	inst_trap_return(ins)	(((ins)&0xff) == I_IRET)
79 #define	inst_return(ins)	(((ins)&0xff) == I_RET)
80 #define	inst_call(ins)		(((ins)&0xff) == I_CALL || \
81 				 (((ins)&0xff) == I_CALLI && \
82 				  ((ins)&0x3800) == 0x1000))
83 #define inst_load(ins)		0
84 #define inst_store(ins)		0
85 
86 /*
87  * There no interesting addresses below _kstack = 0xefbfe000.  There
88  * are small absolute values for GUPROF, but we don't want to see them.
89  * Treat "negative" addresses below _kstack as non-small to allow for
90  * future reductions of _kstack and to avoid sign extension problems.
91  *
92  * There is one interesting symbol above -db_maxoff = 0xffff0000,
93  * namely _APTD = 0xfffff000.  Accepting this would mess up the
94  * printing of small negative offsets.  The next largest symbol is
95  * _APTmap = 0xffc00000.  Accepting this is OK (unless db_maxoff is
96  * set to >= 0x400000 - (max stack offset)).
97  */
98 #define	DB_SMALL_VALUE_MAX	0x7fffffff
99 #define	DB_SMALL_VALUE_MIN	(-0x400001)
100 
101 int	db_segsize(struct trapframe *tfp);
102 
103 #endif /* !_MACHINE_DB_MACHDEP_H_ */
104