xref: /freebsd/sys/arm/arm/db_interface.c (revision aa0a1e58)
1 /*	$NetBSD: db_interface.c,v 1.33 2003/08/25 04:51:10 mrg Exp $	*/
2 
3 /*-
4  * Copyright (c) 1996 Scott K. Stevens
5  *
6  * Mach Operating System
7  * Copyright (c) 1991,1990 Carnegie Mellon University
8  * All Rights Reserved.
9  *
10  * Permission to use, copy, modify and distribute this software and its
11  * documentation is hereby granted, provided that both the copyright
12  * notice and this permission notice appear in all copies of the
13  * software, derivative works or modified versions, and any portions
14  * thereof, and that both notices appear in supporting documentation.
15  *
16  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
17  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
18  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
19  *
20  * Carnegie Mellon requests users of this software to return to
21  *
22  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
23  *  School of Computer Science
24  *  Carnegie Mellon University
25  *  Pittsburgh PA 15213-3890
26  *
27  * any improvements or extensions that they make and grant Carnegie the
28  * rights to redistribute these changes.
29  *
30  *	From: db_interface.c,v 2.4 1991/02/05 17:11:13 mrt (CMU)
31  */
32 
33 /*
34  * Interface to new debugger.
35  */
36 
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 #include "opt_ddb.h"
40 
41 #include <sys/param.h>
42 #include <sys/proc.h>
43 #include <sys/reboot.h>
44 #include <sys/systm.h>	/* just for boothowto */
45 #include <sys/exec.h>
46 #ifdef KDB
47 #include <sys/kdb.h>
48 #endif
49 
50 #include <vm/vm.h>
51 #include <vm/pmap.h>
52 #include <vm/vm_map.h>
53 #include <vm/vm_extern.h>
54 
55 #include <machine/db_machdep.h>
56 #include <machine/vmparam.h>
57 #include <machine/cpu.h>
58 
59 #include <ddb/ddb.h>
60 #include <ddb/db_access.h>
61 #include <ddb/db_command.h>
62 #include <ddb/db_output.h>
63 #include <ddb/db_variables.h>
64 #include <ddb/db_sym.h>
65 #include <sys/cons.h>
66 
67 static int nil = 0;
68 
69 int db_access_und_sp (struct db_variable *, db_expr_t *, int);
70 int db_access_abt_sp (struct db_variable *, db_expr_t *, int);
71 int db_access_irq_sp (struct db_variable *, db_expr_t *, int);
72 
73 static db_varfcn_t db_frame;
74 
75 #define DB_OFFSET(x)	(db_expr_t *)offsetof(struct trapframe, x)
76 struct db_variable db_regs[] = {
77 	{ "spsr", DB_OFFSET(tf_spsr),	db_frame },
78 	{ "r0", DB_OFFSET(tf_r0),	db_frame },
79 	{ "r1", DB_OFFSET(tf_r1),	db_frame },
80 	{ "r2", DB_OFFSET(tf_r2),	db_frame },
81 	{ "r3", DB_OFFSET(tf_r3),	db_frame },
82 	{ "r4", DB_OFFSET(tf_r4),	db_frame },
83 	{ "r5", DB_OFFSET(tf_r5),	db_frame },
84 	{ "r6", DB_OFFSET(tf_r6),	db_frame },
85 	{ "r7", DB_OFFSET(tf_r7),	db_frame },
86 	{ "r8", DB_OFFSET(tf_r8),	db_frame },
87 	{ "r9", DB_OFFSET(tf_r9),	db_frame },
88 	{ "r10", DB_OFFSET(tf_r10),	db_frame },
89 	{ "r11", DB_OFFSET(tf_r11),	db_frame },
90 	{ "r12", DB_OFFSET(tf_r12),	db_frame },
91 	{ "usr_sp", DB_OFFSET(tf_usr_sp), db_frame },
92 	{ "usr_lr", DB_OFFSET(tf_usr_lr), db_frame },
93 	{ "svc_sp", DB_OFFSET(tf_svc_sp), db_frame },
94 	{ "svc_lr", DB_OFFSET(tf_svc_lr), db_frame },
95 	{ "pc", DB_OFFSET(tf_pc), 	db_frame },
96 	{ "und_sp", &nil, db_access_und_sp, },
97 	{ "abt_sp", &nil, db_access_abt_sp, },
98 	{ "irq_sp", &nil, db_access_irq_sp, },
99 };
100 
101 struct db_variable *db_eregs = db_regs + sizeof(db_regs)/sizeof(db_regs[0]);
102 
103 int
104 db_access_und_sp(struct db_variable *vp, db_expr_t *valp, int rw)
105 {
106 
107 	if (rw == DB_VAR_GET) {
108 		*valp = get_stackptr(PSR_UND32_MODE);
109 		return (1);
110 	}
111 	return (0);
112 }
113 
114 int
115 db_access_abt_sp(struct db_variable *vp, db_expr_t *valp, int rw)
116 {
117 
118 	if (rw == DB_VAR_GET) {
119 		*valp = get_stackptr(PSR_ABT32_MODE);
120 		return (1);
121 	}
122 	return (0);
123 }
124 
125 int
126 db_access_irq_sp(struct db_variable *vp, db_expr_t *valp, int rw)
127 {
128 
129 	if (rw == DB_VAR_GET) {
130 		*valp = get_stackptr(PSR_IRQ32_MODE);
131 		return (1);
132 	}
133 	return (0);
134 }
135 
136 int db_frame(struct db_variable *vp, db_expr_t *valp, int rw)
137 {
138 	int *reg;
139 
140 	if (kdb_frame == NULL)
141 		return (0);
142 
143 	reg = (int *)((uintptr_t)kdb_frame + (db_expr_t)vp->valuep);
144 	if (rw == DB_VAR_GET)
145 		*valp = *reg;
146 	else
147 		*reg = *valp;
148 	return (1);
149 }
150 
151 void
152 db_show_mdpcpu(struct pcpu *pc)
153 {
154 }
155 int
156 db_validate_address(vm_offset_t addr)
157 {
158 	struct proc *p = curproc;
159 	struct pmap *pmap;
160 
161 	if (!p || !p->p_vmspace || !p->p_vmspace->vm_map.pmap ||
162 #ifndef ARM32_NEW_VM_LAYOUT
163 	    addr >= VM_MAXUSER_ADDRESS
164 #else
165 	    addr >= VM_MIN_KERNEL_ADDRESS
166 #endif
167 	   )
168 		pmap = pmap_kernel();
169 	else
170 		pmap = p->p_vmspace->vm_map.pmap;
171 
172 	return (pmap_extract(pmap, addr) == FALSE);
173 }
174 
175 /*
176  * Read bytes from kernel address space for debugger.
177  */
178 int
179 db_read_bytes(addr, size, data)
180 	vm_offset_t	addr;
181 	size_t	size;
182 	char	*data;
183 {
184 	char	*src = (char *)addr;
185 
186 	if (db_validate_address((u_int)src)) {
187 		db_printf("address %p is invalid\n", src);
188 		return (-1);
189 	}
190 
191 	if (size == 4 && (addr & 3) == 0 && ((uintptr_t)data & 3) == 0) {
192 		*((int*)data) = *((int*)src);
193 		return (0);
194 	}
195 
196 	if (size == 2 && (addr & 1) == 0 && ((uintptr_t)data & 1) == 0) {
197 		*((short*)data) = *((short*)src);
198 		return (0);
199 	}
200 
201 	while (size-- > 0) {
202 		if (db_validate_address((u_int)src)) {
203 			db_printf("address %p is invalid\n", src);
204 			return (-1);
205 		}
206 		*data++ = *src++;
207 	}
208 	return (0);
209 }
210 
211 /*
212  * Write bytes to kernel address space for debugger.
213  */
214 int
215 db_write_bytes(vm_offset_t addr, size_t size, char *data)
216 {
217 	char *dst;
218 	size_t loop;
219 
220 	dst = (char *)addr;
221 	if (db_validate_address((u_int)dst)) {
222 		db_printf("address %p is invalid\n", dst);
223 		return (0);
224 	}
225 
226 	if (size == 4 && (addr & 3) == 0 && ((uintptr_t)data & 3) == 0)
227 		*((int*)dst) = *((int*)data);
228 	else
229 	if (size == 2 && (addr & 1) == 0 && ((uintptr_t)data & 1) == 0)
230 		*((short*)dst) = *((short*)data);
231 	else {
232 		loop = size;
233 		while (loop-- > 0) {
234 			if (db_validate_address((u_int)dst)) {
235 				db_printf("address %p is invalid\n", dst);
236 				return (-1);
237 			}
238 			*dst++ = *data++;
239 		}
240 	}
241 
242 	/* make sure the caches and memory are in sync */
243 	cpu_icache_sync_range(addr, size);
244 
245 	/* In case the current page tables have been modified ... */
246 	cpu_tlb_flushID();
247 	cpu_cpwait();
248 	return (0);
249 }
250 
251 
252 static u_int
253 db_fetch_reg(int reg)
254 {
255 
256 	switch (reg) {
257 	case 0:
258 		return (kdb_frame->tf_r0);
259 	case 1:
260 		return (kdb_frame->tf_r1);
261 	case 2:
262 		return (kdb_frame->tf_r2);
263 	case 3:
264 		return (kdb_frame->tf_r3);
265 	case 4:
266 		return (kdb_frame->tf_r4);
267 	case 5:
268 		return (kdb_frame->tf_r5);
269 	case 6:
270 		return (kdb_frame->tf_r6);
271 	case 7:
272 		return (kdb_frame->tf_r7);
273 	case 8:
274 		return (kdb_frame->tf_r8);
275 	case 9:
276 		return (kdb_frame->tf_r9);
277 	case 10:
278 		return (kdb_frame->tf_r10);
279 	case 11:
280 		return (kdb_frame->tf_r11);
281 	case 12:
282 		return (kdb_frame->tf_r12);
283 	case 13:
284 		return (kdb_frame->tf_svc_sp);
285 	case 14:
286 		return (kdb_frame->tf_svc_lr);
287 	case 15:
288 		return (kdb_frame->tf_pc);
289 	default:
290 		panic("db_fetch_reg: botch");
291 	}
292 }
293 
294 u_int
295 branch_taken(u_int insn, db_addr_t pc)
296 {
297 	u_int addr, nregs, offset = 0;
298 
299 	switch ((insn >> 24) & 0xf) {
300 	case 0x2:	/* add pc, reg1, #value */
301 	case 0x0:	/* add pc, reg1, reg2, lsl #offset */
302 		addr = db_fetch_reg((insn >> 16) & 0xf);
303 		if (((insn >> 16) & 0xf) == 15)
304 			addr += 8;
305 		if (insn & 0x0200000) {
306 			offset = (insn >> 7) & 0x1e;
307 			offset = (insn & 0xff) << (32 - offset) |
308 			    (insn & 0xff) >> offset;
309 		} else {
310 
311 			offset = db_fetch_reg(insn & 0x0f);
312 			if ((insn & 0x0000ff0) != 0x00000000) {
313 				if (insn & 0x10)
314 					nregs = db_fetch_reg((insn >> 8) & 0xf);
315 				else
316 					nregs = (insn >> 7) & 0x1f;
317 				switch ((insn >> 5) & 3) {
318 				case 0:
319 					/* lsl */
320 					offset = offset << nregs;
321 					break;
322 				case 1:
323 					/* lsr */
324 					offset = offset >> nregs;
325 					break;
326 				default:
327 					break; /* XXX */
328 				}
329 
330 			}
331 			return (addr + offset);
332 
333 		}
334 
335 	case 0xa:	/* b ... */
336 	case 0xb:	/* bl ... */
337 		addr = ((insn << 2) & 0x03ffffff);
338 		if (addr & 0x02000000)
339 			addr |= 0xfc000000;
340 		return (pc + 8 + addr);
341 	case 0x7:	/* ldr pc, [pc, reg, lsl #2] */
342 		addr = db_fetch_reg(insn & 0xf);
343 		addr = pc + 8 + (addr << 2);
344 		db_read_bytes(addr, 4, (char *)&addr);
345 		return (addr);
346 	case 0x1:	/* mov pc, reg */
347 		addr = db_fetch_reg(insn & 0xf);
348 		return (addr);
349 	case 0x4:
350 	case 0x5:	/* ldr pc, [reg] */
351 		addr = db_fetch_reg((insn >> 16) & 0xf);
352 		/* ldr pc, [reg, #offset] */
353 		if (insn & (1 << 24))
354 			offset = insn & 0xfff;
355 		if (insn & 0x00800000)
356 			addr += offset;
357 		else
358 			addr -= offset;
359 		db_read_bytes(addr, 4, (char *)&addr);
360 		return (addr);
361 	case 0x8:	/* ldmxx reg, {..., pc} */
362 	case 0x9:
363 		addr = db_fetch_reg((insn >> 16) & 0xf);
364 		nregs = (insn  & 0x5555) + ((insn  >> 1) & 0x5555);
365 		nregs = (nregs & 0x3333) + ((nregs >> 2) & 0x3333);
366 		nregs = (nregs + (nregs >> 4)) & 0x0f0f;
367 		nregs = (nregs + (nregs >> 8)) & 0x001f;
368 		switch ((insn >> 23) & 0x3) {
369 		case 0x0:	/* ldmda */
370 			addr = addr - 0;
371 			break;
372 		case 0x1:	/* ldmia */
373 			addr = addr + 0 + ((nregs - 1) << 2);
374 			break;
375 		case 0x2:	/* ldmdb */
376 			addr = addr - 4;
377 			break;
378 		case 0x3:	/* ldmib */
379 			addr = addr + 4 + ((nregs - 1) << 2);
380 			break;
381 		}
382 		db_read_bytes(addr, 4, (char *)&addr);
383 		return (addr);
384 	default:
385 		panic("branch_taken: botch");
386 	}
387 }
388