xref: /openbmc/u-boot/cmd/bedbug.c (revision de820365)
1 /*
2  * BedBug Functions
3  */
4 
5 #include <common.h>
6 #include <cli.h>
7 #include <command.h>
8 #include <console.h>
9 #include <linux/ctype.h>
10 #include <net.h>
11 #include <bedbug/type.h>
12 #include <bedbug/bedbug.h>
13 #include <bedbug/regs.h>
14 #include <bedbug/ppc.h>
15 
16 DECLARE_GLOBAL_DATA_PTR;
17 
18 extern void show_regs __P ((struct pt_regs *));
19 extern int run_command __P ((const char *, int));
20 
21 ulong dis_last_addr = 0;	/* Last address disassembled   */
22 ulong dis_last_len = 20;	/* Default disassembler length */
23 CPU_DEBUG_CTX bug_ctx;		/* Bedbug context structure    */
24 
25 
26 /* ======================================================================
27  * U-Boot's puts function does not append a newline, so the bedbug stuff
28  * will use this for the output of the dis/assembler.
29  * ====================================================================== */
30 
31 int bedbug_puts (const char *str)
32 {
33 	/* -------------------------------------------------- */
34 
35 	printf ("%s\r\n", str);
36 	return 0;
37 }				/* bedbug_puts */
38 
39 
40 
41 /* ======================================================================
42  * Initialize the bug_ctx structure used by the bedbug debugger.  This is
43  * specific to the CPU since each has different debug registers and
44  * settings.
45  * ====================================================================== */
46 
47 void bedbug_init (void)
48 {
49 	/* -------------------------------------------------- */
50 
51 #if defined(CONFIG_4xx)
52 	void bedbug405_init (void);
53 
54 	bedbug405_init ();
55 #endif
56 
57 	return;
58 }				/* bedbug_init */
59 
60 
61 
62 /* ======================================================================
63  * Entry point from the interpreter to the disassembler.  Repeated calls
64  * will resume from the last disassembled address.
65  * ====================================================================== */
66 int do_bedbug_dis (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
67 {
68 	ulong addr;		/* Address to start disassembly from    */
69 	ulong len;		/* # of instructions to disassemble     */
70 
71 	/* -------------------------------------------------- */
72 
73 	/* Setup to go from the last address if none is given */
74 	addr = dis_last_addr;
75 	len = dis_last_len;
76 
77 	if (argc < 2)
78 		return CMD_RET_USAGE;
79 
80 	if ((flag & CMD_FLAG_REPEAT) == 0) {
81 		/* New command */
82 		addr = simple_strtoul (argv[1], NULL, 16);
83 
84 		/* If an extra param is given then it is the length */
85 		if (argc > 2)
86 			len = simple_strtoul (argv[2], NULL, 16);
87 	}
88 
89 	/* Run the disassembler */
90 	disppc ((unsigned char *) addr, 0, len, bedbug_puts, F_RADHEX);
91 
92 	dis_last_addr = addr + (len * 4);
93 	dis_last_len = len;
94 	return 0;
95 }				/* do_bedbug_dis */
96 
97 U_BOOT_CMD (ds, 3, 1, do_bedbug_dis,
98 	    "disassemble memory",
99 	    "ds <address> [# instructions]");
100 
101 /* ======================================================================
102  * Entry point from the interpreter to the assembler.  Assembles
103  * instructions in consecutive memory locations until a '.' (period) is
104  * entered on a line by itself.
105  * ====================================================================== */
106 int do_bedbug_asm (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
107 {
108 	long mem_addr;		/* Address to assemble into     */
109 	unsigned long instr;	/* Machine code for text        */
110 	char prompt[15];	/* Prompt string for user input */
111 	int asm_err;		/* Error code from the assembler */
112 
113 	/* -------------------------------------------------- */
114 	int rcode = 0;
115 
116 	if (argc < 2)
117 		return CMD_RET_USAGE;
118 
119 	printf ("\nEnter '.' when done\n");
120 	mem_addr = simple_strtoul (argv[1], NULL, 16);
121 
122 	while (1) {
123 		putc ('\n');
124 		disppc ((unsigned char *) mem_addr, 0, 1, bedbug_puts,
125 			F_RADHEX);
126 
127 		sprintf (prompt, "%08lx:    ", mem_addr);
128 		cli_readline(prompt);
129 
130 		if (console_buffer[0] && strcmp (console_buffer, ".")) {
131 			if ((instr =
132 			     asmppc (mem_addr, console_buffer,
133 				     &asm_err)) != 0) {
134 				*(unsigned long *) mem_addr = instr;
135 				mem_addr += 4;
136 			} else {
137 				printf ("*** Error: %s ***\n",
138 					asm_error_str (asm_err));
139 				rcode = 1;
140 			}
141 		} else {
142 			break;
143 		}
144 	}
145 	return rcode;
146 }				/* do_bedbug_asm */
147 
148 U_BOOT_CMD (as, 2, 0, do_bedbug_asm,
149 	    "assemble memory", "as <address>");
150 
151 /* ======================================================================
152  * Used to set a break point from the interpreter.  Simply calls into the
153  * CPU-specific break point set routine.
154  * ====================================================================== */
155 
156 int do_bedbug_break (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
157 {
158 	/* -------------------------------------------------- */
159 	if (bug_ctx.do_break)
160 		(*bug_ctx.do_break) (cmdtp, flag, argc, argv);
161 	return 0;
162 
163 }				/* do_bedbug_break */
164 
165 U_BOOT_CMD (break, 3, 0, do_bedbug_break,
166 	    "set or clear a breakpoint",
167 	    " - Set or clear a breakpoint\n"
168 	    "break <address> - Break at an address\n"
169 	    "break off <bp#> - Disable breakpoint.\n"
170 	    "break show      - List breakpoints.");
171 
172 /* ======================================================================
173  * Called from the debug interrupt routine.  Simply calls the CPU-specific
174  * breakpoint handling routine.
175  * ====================================================================== */
176 
177 void do_bedbug_breakpoint (struct pt_regs *regs)
178 {
179 	/* -------------------------------------------------- */
180 
181 	if (bug_ctx.break_isr)
182 		(*bug_ctx.break_isr) (regs);
183 
184 	return;
185 }				/* do_bedbug_breakpoint */
186 
187 
188 
189 /* ======================================================================
190  * Called from the CPU-specific breakpoint handling routine.  Enter a
191  * mini main loop until the stopped flag is cleared from the breakpoint
192  * context.
193  *
194  * This handles the parts of the debugger that are common to all CPU's.
195  * ====================================================================== */
196 
197 void bedbug_main_loop (unsigned long addr, struct pt_regs *regs)
198 {
199 	int len;		/* Length of command line */
200 	int flag;		/* Command flags          */
201 	int rc = 0;		/* Result from run_command */
202 	char prompt_str[20];	/* Prompt string          */
203 	static char lastcommand[CONFIG_SYS_CBSIZE] = { 0 };	/* previous command */
204 	/* -------------------------------------------------- */
205 
206 	if (bug_ctx.clear)
207 		(*bug_ctx.clear) (bug_ctx.current_bp);
208 
209 	printf ("Breakpoint %d: ", bug_ctx.current_bp);
210 	disppc ((unsigned char *) addr, 0, 1, bedbug_puts, F_RADHEX);
211 
212 	bug_ctx.stopped = 1;
213 	bug_ctx.regs = regs;
214 
215 	sprintf (prompt_str, "BEDBUG.%d =>", bug_ctx.current_bp);
216 
217 	/* A miniature main loop */
218 	while (bug_ctx.stopped) {
219 		len = cli_readline(prompt_str);
220 
221 		flag = 0;	/* assume no special flags for now */
222 
223 		if (len > 0)
224 			strcpy (lastcommand, console_buffer);
225 		else if (len == 0)
226 			flag |= CMD_FLAG_REPEAT;
227 
228 		if (len == -1)
229 			printf ("<INTERRUPT>\n");
230 		else
231 			rc = run_command_repeatable(lastcommand, flag);
232 
233 		if (rc <= 0) {
234 			/* invalid command or not repeatable, forget it */
235 			lastcommand[0] = 0;
236 		}
237 	}
238 
239 	bug_ctx.regs = NULL;
240 	bug_ctx.current_bp = 0;
241 
242 	return;
243 }				/* bedbug_main_loop */
244 
245 
246 
247 /* ======================================================================
248  * Interpreter command to continue from a breakpoint.  Just clears the
249  * stopped flag in the context so that the breakpoint routine will
250  * return.
251  * ====================================================================== */
252 int do_bedbug_continue (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
253 {
254 	/* -------------------------------------------------- */
255 
256 	if (!bug_ctx.stopped) {
257 		printf ("Not at a breakpoint\n");
258 		return 1;
259 	}
260 
261 	bug_ctx.stopped = 0;
262 	return 0;
263 }				/* do_bedbug_continue */
264 
265 U_BOOT_CMD (continue, 1, 0, do_bedbug_continue,
266 	    "continue from a breakpoint",
267 	    "");
268 
269 /* ======================================================================
270  * Interpreter command to continue to the next instruction, stepping into
271  * subroutines.  Works by calling the find_next_addr() routine to compute
272  * the address passes control to the CPU-specific set breakpoint routine
273  * for the current breakpoint number.
274  * ====================================================================== */
275 int do_bedbug_step (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
276 {
277 	unsigned long addr;	/* Address to stop at */
278 
279 	/* -------------------------------------------------- */
280 
281 	if (!bug_ctx.stopped) {
282 		printf ("Not at a breakpoint\n");
283 		return 1;
284 	}
285 
286 	if (!find_next_address((unsigned char *) &addr, false, bug_ctx.regs))
287 		return 1;
288 
289 	if (bug_ctx.set)
290 		(*bug_ctx.set) (bug_ctx.current_bp, addr);
291 
292 	bug_ctx.stopped = 0;
293 	return 0;
294 }				/* do_bedbug_step */
295 
296 U_BOOT_CMD (step, 1, 1, do_bedbug_step,
297 	    "single step execution.",
298 	    "");
299 
300 /* ======================================================================
301  * Interpreter command to continue to the next instruction, stepping over
302  * subroutines.  Works by calling the find_next_addr() routine to compute
303  * the address passes control to the CPU-specific set breakpoint routine
304  * for the current breakpoint number.
305  * ====================================================================== */
306 int do_bedbug_next (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
307 {
308 	unsigned long addr;	/* Address to stop at */
309 
310 	/* -------------------------------------------------- */
311 
312 	if (!bug_ctx.stopped) {
313 		printf ("Not at a breakpoint\n");
314 		return 1;
315 	}
316 
317 	if (!find_next_address((unsigned char *) &addr, true, bug_ctx.regs))
318 		return 1;
319 
320 	if (bug_ctx.set)
321 		(*bug_ctx.set) (bug_ctx.current_bp, addr);
322 
323 	bug_ctx.stopped = 0;
324 	return 0;
325 }				/* do_bedbug_next */
326 
327 U_BOOT_CMD (next, 1, 1, do_bedbug_next,
328 	    "single step execution, stepping over subroutines.",
329 	    "");
330 
331 /* ======================================================================
332  * Interpreter command to print the current stack.  This assumes an EABI
333  * architecture, so it starts with GPR R1 and works back up the stack.
334  * ====================================================================== */
335 int do_bedbug_stack (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
336 {
337 	unsigned long sp;	/* Stack pointer                */
338 	unsigned long func;	/* LR from stack                */
339 	int depth;		/* Stack iteration level        */
340 	int skip = 1;		/* Flag to skip the first entry */
341 	unsigned long top;	/* Top of memory address        */
342 
343 	/* -------------------------------------------------- */
344 
345 	if (!bug_ctx.stopped) {
346 		printf ("Not at a breakpoint\n");
347 		return 1;
348 	}
349 
350 	top = gd->bd->bi_memstart + gd->bd->bi_memsize;
351 	depth = 0;
352 
353 	printf ("Depth     PC\n");
354 	printf ("-----  --------\n");
355 	printf ("%5d  %08lx\n", depth++, bug_ctx.regs->nip);
356 
357 	sp = bug_ctx.regs->gpr[1];
358 	func = *(unsigned long *) (sp + 4);
359 
360 	while ((func < top) && (sp < top)) {
361 		if (!skip)
362 			printf ("%5d  %08lx\n", depth++, func);
363 		else
364 			--skip;
365 
366 		sp = *(unsigned long *) sp;
367 		func = *(unsigned long *) (sp + 4);
368 	}
369 	return 0;
370 }				/* do_bedbug_stack */
371 
372 U_BOOT_CMD (where, 1, 1, do_bedbug_stack,
373 	    "Print the running stack.",
374 	    "");
375 
376 /* ======================================================================
377  * Interpreter command to dump the registers.  Calls the CPU-specific
378  * show registers routine.
379  * ====================================================================== */
380 int do_bedbug_rdump (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
381 {
382 	/* -------------------------------------------------- */
383 
384 	if (!bug_ctx.stopped) {
385 		printf ("Not at a breakpoint\n");
386 		return 1;
387 	}
388 
389 	show_regs (bug_ctx.regs);
390 	return 0;
391 }				/* do_bedbug_rdump */
392 
393 U_BOOT_CMD (rdump, 1, 1, do_bedbug_rdump,
394 	    "Show registers.", "");
395 /* ====================================================================== */
396 
397 
398 /*
399  * Copyright (c) 2001 William L. Pitts
400  * All rights reserved.
401  *
402  * Redistribution and use in source and binary forms are freely
403  * permitted provided that the above copyright notice and this
404  * paragraph and the following disclaimer are duplicated in all
405  * such forms.
406  *
407  * This software is provided "AS IS" and without any express or
408  * implied warranties, including, without limitation, the implied
409  * warranties of merchantability and fitness for a particular
410  * purpose.
411  */
412