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sparclet-stub.c @ 444

Last change on this file since 444 was 444, checked in by satin@…, 6 years ago
add newlib,libalmos-mkh, restructure shared_syscalls.h and mini-libc
File size: 30.0 KB

Line
1	/****************************************************************************
2
3	THIS SOFTWARE IS NOT COPYRIGHTED
4
5	HP offers the following for use in the public domain. HP makes no
6	warranty with regard to the software or it's performance and the
7	user accepts the software "AS IS" with all faults.
8
9	HP DISCLAIMS ANY WARRANTIES, EXPRESS OR IMPLIED, WITH REGARD
10	TO THIS SOFTWARE INCLUDING BUT NOT LIMITED TO THE WARRANTIES
11	OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
12
13	****************************************************************************/
14
15	/****************************************************************************
16	* Header: remcom.c,v 1.34 91/03/09 12:29:49 glenne Exp $
17	*
18	* Module name: remcom.c $
19	* Revision: 1.34 $
20	* Date: 91/03/09 12:29:49 $
21	* Contributor: Lake Stevens Instrument Division$
22	*
23	* Description: low level support for gdb debugger. $
24	*
25	* Considerations: only works on target hardware $
26	*
27	* Written by: Glenn Engel $
28	* ModuleState: Experimental $
29	*
30	* NOTES: See Below $
31	*
32	* Modified for SPARC by Stu Grossman, Cygnus Support.
33	* Based on sparc-stub.c, it's modified for SPARClite Debug Unit hardware
34	* breakpoint support to create sparclite-stub.c, by Kung Hsu, Cygnus Support.
35	*
36	* This code has been extensively tested on the Fujitsu SPARClite demo board.
37	*
38	* To enable debugger support, two things need to happen. One, a
39	* call to set_debug_traps() is necessary in order to allow any breakpoints
40	* or error conditions to be properly intercepted and reported to gdb.
41	* Two, a breakpoint needs to be generated to begin communication. This
42	* is most easily accomplished by a call to breakpoint(). Breakpoint()
43	* simulates a breakpoint by executing a trap #1.
44	*
45	*************
46	*
47	* The following gdb commands are supported:
48	*
49	* command function Return value
50	*
51	* g return the value of the CPU registers hex data or ENN
52	* G set the value of the CPU registers OK or ENN
53	* P set the value of a single CPU register OK or P01 (???)
54	*
55	* mAA..AA,LLLL Read LLLL bytes at address AA..AA hex data or ENN
56	* MAA..AA,LLLL: Write LLLL bytes at address AA.AA OK or ENN
57	*
58	* c Resume at current address SNN ( signal NN)
59	* cAA..AA Continue at address AA..AA SNN
60	*
61	* s Step one instruction SNN
62	* sAA..AA Step one instruction from AA..AA SNN
63	*
64	* k kill
65	*
66	* ? What was the last sigval ? SNN (signal NN)
67	*
68	* bBB..BB Set baud rate to BB..BB OK or BNN, then sets
69	* baud rate
70	*
71	* All commands and responses are sent with a packet which includes a
72	* checksum. A packet consists of
73	*
74	* $<packet info>#<checksum>.
75	*
76	* where
77	* <packet info> :: <characters representing the command or response>
78	* <checksum> :: <two hex digits computed as modulo 256 sum of <packetinfo>>
79	*
80	* When a packet is received, it is first acknowledged with either '+' or '-'.
81	* '+' indicates a successful transfer. '-' indicates a failed transfer.
82	*
83	* Example:
84	*
85	* Host: Reply:
86	* $m0,10#2a +$00010203040506070809101112131415#42
87	*
88	****************************************************************************/
89
90	#include <string.h>
91	#include <signal.h>
92
93	/************************************************************************
94	*
95	* external low-level support routines
96	*/
97
98	extern putDebugChar(); /* write a single character */
99	extern getDebugChar(); /* read and return a single char */
100
101	/************************************************************************/
102	/* BUFMAX defines the maximum number of characters in inbound/outbound buffers*/
103	/* at least NUMREGBYTES2 are needed for register packets /
104	#define BUFMAX 2048
105
106	static int initialized = 0; /* !0 means we've been initialized */
107	static int remote_debug = 0; /* turn on verbose debugging */
108
109	extern void breakinst();
110	void _cprint();
111	static void hw_breakpoint();
112	static void set_mem_fault_trap();
113	static void get_in_break_mode();
114	static unsigned char *mem2hex();
115
116	static const char hexchars[]="0123456789abcdef";
117
118	#define NUMREGS 121
119
120	static unsigned long saved_stack_pointer;
121
122	/* Number of bytes of registers. */
123	#define NUMREGBYTES (NUMREGS * 4)
124	enum regnames { G0, G1, G2, G3, G4, G5, G6, G7,
125	O0, O1, O2, O3, O4, O5, SP, O7,
126	L0, L1, L2, L3, L4, L5, L6, L7,
127	I0, I1, I2, I3, I4, I5, FP, I7,
128
129	F0, F1, F2, F3, F4, F5, F6, F7,
130	F8, F9, F10, F11, F12, F13, F14, F15,
131	F16, F17, F18, F19, F20, F21, F22, F23,
132	F24, F25, F26, F27, F28, F29, F30, F31,
133
134	Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR,
135	CCSR, CCPR, CCCRCR, CCOR, CCOBR, CCIBR, CCIR, UNUSED1,
136
137	ASR1, ASR15, ASR17, ASR18, ASR19, ASR20, ASR21, ASR22,
138	/* the following not actually implemented */
139	AWR0, AWR1, AWR2, AWR3, AWR4, AWR5, AWR6, AWR7,
140	AWR8, AWR9, AWR10, AWR11, AWR12, AWR13, AWR14, AWR15,
141	AWR16, AWR17, AWR18, AWR19, AWR20, AWR21, AWR22, AWR23,
142	AWR24, AWR25, AWR26, AWR27, AWR28, AWR29, AWR30, AWR31,
143	APSR
144	};
145
146	/************************* ASSEMBLY CODE MACROS ***********************/
147	/* */
148
149	extern void trap_low();
150
151	asm("
152	.reserve trapstack, 1000 * 4, \"bss\", 8
153
154	.data
155	.align 4
156
157	in_trap_handler:
158	.word 0
159
160	.text
161	.align 4
162
163	! This function is called when any SPARC trap (except window overflow or
164	! underflow) occurs. It makes sure that the invalid register window is still
165	! available before jumping into C code. It will also restore the world if you
166	! return from handle_exception.
167	!
168	! On entry, trap_low expects l1 and l2 to contain pc and npc respectivly.
169
170	.globl _trap_low
171	_trap_low:
172	mov %psr, %l0
173	mov %wim, %l3
174
175	srl %l3, %l0, %l4 ! wim >> cwp
176	and %l4, 0xff, %l4 ! Mask off windows 28, 29
177	cmp %l4, 1
178	bne window_fine ! Branch if not in the invalid window
179	nop
180
181	! Handle window overflow
182
183	mov %g1, %l4 ! Save g1, we use it to hold the wim
184	srl %l3, 1, %g1 ! Rotate wim right
185	and %g1, 0xff, %g1 ! Mask off windows 28, 29
186	tst %g1
187	bg good_wim ! Branch if new wim is non-zero
188	nop
189
190	! At this point, we need to bring a 1 into the high order bit of the wim.
191	! Since we don't want to make any assumptions about the number of register
192	! windows, we figure it out dynamically so as to setup the wim correctly.
193
194	! The normal way doesn't work on the sparclet as register windows
195	! 28 and 29 are special purpose windows.
196	!not %g1 ! Fill g1 with ones
197	!mov %g1, %wim ! Fill the wim with ones
198	!nop
199	!nop
200	!nop
201	!mov %wim, %g1 ! Read back the wim
202	!inc %g1 ! Now g1 has 1 just to left of wim
203	!srl %g1, 1, %g1 ! Now put 1 at top of wim
204
205	mov 0x80, %g1 ! Hack for sparclet
206
207	! This doesn't work on the sparclet.
208	!mov %g0, %wim ! Clear wim so that subsequent save
209	! won't trap
210	andn %l3, 0xff, %l5 ! Clear wim but not windows 28, 29
211	mov %l5, %wim
212	nop
213	nop
214	nop
215
216	good_wim:
217	save %g0, %g0, %g0 ! Slip into next window
218	mov %g1, %wim ! Install the new wim
219
220	std %l0, [%sp + 0 * 4] ! save L & I registers
221	std %l2, [%sp + 2 * 4]
222	std %l4, [%sp + 4 * 4]
223	std %l6, [%sp + 6 * 4]
224
225	std %i0, [%sp + 8 * 4]
226	std %i2, [%sp + 10 * 4]
227	std %i4, [%sp + 12 * 4]
228	std %i6, [%sp + 14 * 4]
229
230	restore ! Go back to trap window.
231	mov %l4, %g1 ! Restore %g1
232
233	window_fine:
234	sethi %hi(in_trap_handler), %l4
235	ld [%lo(in_trap_handler) + %l4], %l5
236	tst %l5
237	bg recursive_trap
238	inc %l5
239
240	set trapstack+1000*4, %sp ! Switch to trap stack
241
242	recursive_trap:
243	st %l5, [%lo(in_trap_handler) + %l4]
244	sub %sp,(16+1+6+1+88)*4,%sp ! Make room for input & locals
245	! + hidden arg + arg spill
246	! + doubleword alignment
247	! + registers[121]
248
249	std %g0, [%sp + (24 + 0) * 4] ! registers[Gx]
250	std %g2, [%sp + (24 + 2) * 4]
251	std %g4, [%sp + (24 + 4) * 4]
252	std %g6, [%sp + (24 + 6) * 4]
253
254	std %i0, [%sp + (24 + 8) * 4] ! registers[Ox]
255	std %i2, [%sp + (24 + 10) * 4]
256	std %i4, [%sp + (24 + 12) * 4]
257	std %i6, [%sp + (24 + 14) * 4]
258
259	! FP regs (sparclet doesn't have fpu)
260
261	mov %y, %l4
262	mov %tbr, %l5
263	st %l4, [%sp + (24 + 64) * 4] ! Y
264	st %l0, [%sp + (24 + 65) * 4] ! PSR
265	st %l3, [%sp + (24 + 66) * 4] ! WIM
266	st %l5, [%sp + (24 + 67) * 4] ! TBR
267	st %l1, [%sp + (24 + 68) * 4] ! PC
268	st %l2, [%sp + (24 + 69) * 4] ! NPC
269	! CPSR and FPSR not impl
270	or %l0, 0xf20, %l4
271	mov %l4, %psr ! Turn on traps, disable interrupts
272	nop
273	nop
274	nop
275
276	! Save coprocessor state.
277	! See SK/demo/hdlc_demo/ldc_swap_context.S.
278
279	mov %psr, %l0
280	sethi %hi(0x2000), %l5 ! EC bit in PSR
281	or %l5, %l0, %l5
282	mov %l5, %psr ! enable coprocessor
283	nop ! 3 nops after write to %psr (needed?)
284	nop
285	nop
286	crdcxt %ccsr, %l1 ! capture CCSR
287	mov 0x6, %l2
288	cwrcxt %l2, %ccsr ! set CCP state machine for CCFR
289	crdcxt %ccfr, %l2 ! capture CCOR
290	cwrcxt %l2, %ccfr ! tickle CCFR
291	crdcxt %ccfr, %l3 ! capture CCOBR
292	cwrcxt %l3, %ccfr ! tickle CCFR
293	crdcxt %ccfr, %l4 ! capture CCIBR
294	cwrcxt %l4, %ccfr ! tickle CCFR
295	crdcxt %ccfr, %l5 ! capture CCIR
296	cwrcxt %l5, %ccfr ! tickle CCFR
297	crdcxt %ccpr, %l6 ! capture CCPR
298	crdcxt %cccrcr, %l7 ! capture CCCRCR
299	st %l1, [%sp + (24 + 72) * 4] ! save CCSR
300	st %l2, [%sp + (24 + 75) * 4] ! save CCOR
301	st %l3, [%sp + (24 + 76) * 4] ! save CCOBR
302	st %l4, [%sp + (24 + 77) * 4] ! save CCIBR
303	st %l5, [%sp + (24 + 78) * 4] ! save CCIR
304	st %l6, [%sp + (24 + 73) * 4] ! save CCPR
305	st %l7, [%sp + (24 + 74) * 4] ! save CCCRCR
306	mov %l0, %psr ! restore original PSR
307	nop ! 3 nops after write to %psr (needed?)
308	nop
309	nop
310
311	! End of saving coprocessor state.
312	! Save asr regs
313
314	! Part of this is silly -- we should not display ASR15 or ASR19 at all.
315
316	sethi %hi(0x01000000), %l6
317	st %l6, [%sp + (24 + 81) * 4] ! ASR15 == NOP
318	sethi %hi(0xdeadc0de), %l6
319	or %l6, %lo(0xdeadc0de), %l6
320	st %l6, [%sp + (24 + 84) * 4] ! ASR19 == DEADC0DE
321
322	rd %asr1, %l4
323	st %l4, [%sp + (24 + 80) * 4]
324	! rd %asr15, %l4 ! must not read ASR15
325	! st %l4, [%sp + (24 + 81) * 4] ! (illegal instr trap)
326	rd %asr17, %l4
327	st %l4, [%sp + (24 + 82) * 4]
328	rd %asr18, %l4
329	st %l4, [%sp + (24 + 83) * 4]
330	! rd %asr19, %l4 ! must not read asr19
331	! st %l4, [%sp + (24 + 84) * 4] ! (halts the CPU)
332	rd %asr20, %l4
333	st %l4, [%sp + (24 + 85) * 4]
334	rd %asr21, %l4
335	st %l4, [%sp + (24 + 86) * 4]
336	rd %asr22, %l4
337	st %l4, [%sp + (24 + 87) * 4]
338
339	! End of saving asr regs
340
341	call _handle_exception
342	add %sp, 24 * 4, %o0 ! Pass address of registers
343
344	! Reload all of the registers that aren't on the stack
345
346	ld [%sp + (24 + 1) * 4], %g1 ! registers[Gx]
347	ldd [%sp + (24 + 2) * 4], %g2
348	ldd [%sp + (24 + 4) * 4], %g4
349	ldd [%sp + (24 + 6) * 4], %g6
350
351	ldd [%sp + (24 + 8) * 4], %i0 ! registers[Ox]
352	ldd [%sp + (24 + 10) * 4], %i2
353	ldd [%sp + (24 + 12) * 4], %i4
354	ldd [%sp + (24 + 14) * 4], %i6
355
356	! FP regs (sparclet doesn't have fpu)
357
358	! Update the coprocessor registers.
359	! See SK/demo/hdlc_demo/ldc_swap_context.S.
360
361	mov %psr, %l0
362	sethi %hi(0x2000), %l5 ! EC bit in PSR
363	or %l5, %l0, %l5
364	mov %l5, %psr ! enable coprocessor
365	nop ! 3 nops after write to %psr (needed?)
366	nop
367	nop
368
369	mov 0x6, %l2
370	cwrcxt %l2, %ccsr ! set CCP state machine for CCFR
371
372	ld [%sp + (24 + 72) * 4], %l1 ! saved CCSR
373	ld [%sp + (24 + 75) * 4], %l2 ! saved CCOR
374	ld [%sp + (24 + 76) * 4], %l3 ! saved CCOBR
375	ld [%sp + (24 + 77) * 4], %l4 ! saved CCIBR
376	ld [%sp + (24 + 78) * 4], %l5 ! saved CCIR
377	ld [%sp + (24 + 73) * 4], %l6 ! saved CCPR
378	ld [%sp + (24 + 74) * 4], %l7 ! saved CCCRCR
379
380	cwrcxt %l2, %ccfr ! restore CCOR
381	cwrcxt %l3, %ccfr ! restore CCOBR
382	cwrcxt %l4, %ccfr ! restore CCIBR
383	cwrcxt %l5, %ccfr ! restore CCIR
384	cwrcxt %l6, %ccpr ! restore CCPR
385	cwrcxt %l7, %cccrcr ! restore CCCRCR
386	cwrcxt %l1, %ccsr ! restore CCSR
387
388	mov %l0, %psr ! restore PSR
389	nop ! 3 nops after write to %psr (needed?)
390	nop
391	nop
392
393	! End of coprocessor handling stuff.
394	! Update asr regs
395
396	ld [%sp + (24 + 80) * 4], %l4
397	wr %l4, %asr1
398	! ld [%sp + (24 + 81) * 4], %l4 ! can't write asr15
399	! wr %l4, %asr15
400	ld [%sp + (24 + 82) * 4], %l4
401	wr %l4, %asr17
402	ld [%sp + (24 + 83) * 4], %l4
403	wr %l4, %asr18
404	! ld [%sp + (24 + 84) * 4], %l4 ! can't write asr19
405	! wr %l4, %asr19
406	! ld [%sp + (24 + 85) * 4], %l4 ! can't write asr20
407	! wr %l4, %asr20
408	! ld [%sp + (24 + 86) * 4], %l4 ! can't write asr21
409	! wr %l4, %asr21
410	ld [%sp + (24 + 87) * 4], %l4
411	wr %l4, %asr22
412
413	! End of restoring asr regs
414
415
416	ldd [%sp + (24 + 64) * 4], %l0 ! Y & PSR
417	ldd [%sp + (24 + 68) * 4], %l2 ! PC & NPC
418
419	restore ! Ensure that previous window is valid
420	save %g0, %g0, %g0 ! by causing a window_underflow trap
421
422	mov %l0, %y
423	mov %l1, %psr ! Make sure that traps are disabled
424	! for rett
425	nop ! 3 nops after write to %psr (needed?)
426	nop
427	nop
428
429	sethi %hi(in_trap_handler), %l4
430	ld [%lo(in_trap_handler) + %l4], %l5
431	dec %l5
432	st %l5, [%lo(in_trap_handler) + %l4]
433
434	jmpl %l2, %g0 ! Restore old PC
435	rett %l3 ! Restore old nPC
436	");
437
438	/* Convert ch from a hex digit to an int */
439
440	static int
441	hex(ch)
442	unsigned char ch;
443	{
444	if (ch >= 'a' && ch <= 'f')
445	return ch-'a'+10;
446	if (ch >= '0' && ch <= '9')
447	return ch-'0';
448	if (ch >= 'A' && ch <= 'F')
449	return ch-'A'+10;
450	return -1;
451	}
452
453	/* scan for the sequence $<data>#<checksum> */
454
455	static void
456	getpacket(buffer)
457	char *buffer;
458	{
459	unsigned char checksum;
460	unsigned char xmitcsum;
461	int i;
462	int count;
463	unsigned char ch;
464
465	do
466	{
467	/* wait around for the start character, ignore all other characters */
468	while ((ch = (getDebugChar() & 0x7f)) != '$')
469	;
470
471	checksum = 0;
472	xmitcsum = -1;
473
474	count = 0;
475
476	/* now, read until a # or end of buffer is found */
477	while (count < BUFMAX)
478	{
479	ch = getDebugChar() & 0x7f;
480	if (ch == '#')
481	break;
482	checksum = checksum + ch;
483	buffer[count] = ch;
484	count = count + 1;
485	}
486
487	if (count >= BUFMAX)
488	continue;
489
490	buffer[count] = 0;
491
492	if (ch == '#')
493	{
494	xmitcsum = hex(ch = getDebugChar() & 0x7f) << 4;
495	xmitcsum \|= hex(ch = getDebugChar() & 0x7f);
496
497	if (checksum != xmitcsum)
498	putDebugChar('-'); /* failed checksum */
499	else
500	{
501	putDebugChar('+'); /* successful transfer */
502	/* if a sequence char is present, reply the sequence ID */
503	if (buffer[2] == ':')
504	{
505	putDebugChar(buffer[0]);
506	putDebugChar(buffer[1]);
507	/* remove sequence chars from buffer */
508	count = strlen(buffer);
509	for (i=3; i <= count; i++)
510	buffer[i-3] = buffer[i];
511	}
512	}
513	}
514	}
515	while (checksum != xmitcsum);
516	}
517
518	/* send the packet in buffer. */
519
520	static void
521	putpacket(buffer)
522	unsigned char *buffer;
523	{
524	unsigned char checksum;
525	int count;
526	unsigned char ch;
527
528	/* $<packet info>#<checksum>. */
529	do
530	{
531	putDebugChar('$');
532	checksum = 0;
533	count = 0;
534
535	while (ch = buffer[count])
536	{
537	if (! putDebugChar(ch))
538	return;
539	checksum += ch;
540	count += 1;
541	}
542
543	putDebugChar('#');
544	putDebugChar(hexchars[checksum >> 4]);
545	putDebugChar(hexchars[checksum & 0xf]);
546
547	}
548	while ((getDebugChar() & 0x7f) != '+');
549	}
550
551	static char remcomInBuffer[BUFMAX];
552	static char remcomOutBuffer[BUFMAX];
553
554	/* Indicate to caller of mem2hex or hex2mem that there has been an
555	error. */
556	static volatile int mem_err = 0;
557
558	/* Convert the memory pointed to by mem into hex, placing result in buf.
559	* Return a pointer to the last char put in buf (null), in case of mem fault,
560	* return 0.
561	* If MAY_FAULT is non-zero, then we will handle memory faults by returning
562	* a 0, else treat a fault like any other fault in the stub.
563	*/
564
565	static unsigned char *
566	mem2hex(mem, buf, count, may_fault)
567	unsigned char *mem;
568	unsigned char *buf;
569	int count;
570	int may_fault;
571	{
572	unsigned char ch;
573
574	set_mem_fault_trap(may_fault);
575
576	while (count-- > 0)
577	{
578	ch = *mem++;
579	if (mem_err)
580	return 0;
581	*buf++ = hexchars[ch >> 4];
582	*buf++ = hexchars[ch & 0xf];
583	}
584
585	*buf = 0;
586
587	set_mem_fault_trap(0);
588
589	return buf;
590	}
591
592	/* convert the hex array pointed to by buf into binary to be placed in mem
593	* return a pointer to the character AFTER the last byte written */
594
595	static char *
596	hex2mem(buf, mem, count, may_fault)
597	unsigned char *buf;
598	unsigned char *mem;
599	int count;
600	int may_fault;
601	{
602	int i;
603	unsigned char ch;
604
605	set_mem_fault_trap(may_fault);
606
607	for (i=0; i<count; i++)
608	{
609	ch = hex(*buf++) << 4;
610	ch \|= hex(*buf++);
611	*mem++ = ch;
612	if (mem_err)
613	return 0;
614	}
615
616	set_mem_fault_trap(0);
617
618	return mem;
619	}
620
621	/* This table contains the mapping between SPARC hardware trap types, and
622	signals, which are primarily what GDB understands. It also indicates
623	which hardware traps we need to commandeer when initializing the stub. */
624
625	static struct hard_trap_info
626	{
627	unsigned char tt; /* Trap type code for SPARClite */
628	unsigned char signo; /* Signal that we map this trap into */
629	} hard_trap_info[] = {
630	{1, SIGSEGV}, /* instruction access exception */
631	{0x3b, SIGSEGV}, /* instruction access error */
632	{2, SIGILL}, /* illegal instruction */
633	{3, SIGILL}, /* privileged instruction */
634	{4, SIGEMT}, /* fp disabled */
635	{0x24, SIGEMT}, /* cp disabled */
636	{7, SIGBUS}, /* mem address not aligned */
637	{0x29, SIGSEGV}, /* data access exception */
638	{10, SIGEMT}, /* tag overflow */
639	{128+1, SIGTRAP}, /* ta 1 - normal breakpoint instruction */
640	{0, 0} /* Must be last */
641	};
642
643	/* Set up exception handlers for tracing and breakpoints */
644
645	void
646	set_debug_traps()
647	{
648	struct hard_trap_info *ht;
649
650	for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
651	exceptionHandler(ht->tt, trap_low);
652
653	/* In case GDB is started before us, ack any packets (presumably
654	"$?#xx") sitting there. */
655	putDebugChar ('+');
656
657	initialized = 1;
658	}
659
660	asm ("
661	! Trap handler for memory errors. This just sets mem_err to be non-zero. It
662	! assumes that %l1 is non-zero. This should be safe, as it is doubtful that
663	! 0 would ever contain code that could mem fault. This routine will skip
664	! past the faulting instruction after setting mem_err.
665
666	.text
667	.align 4
668
669	_fltr_set_mem_err:
670	sethi %hi(_mem_err), %l0
671	st %l1, [%l0 + %lo(_mem_err)]
672	jmpl %l2, %g0
673	rett %l2+4
674	");
675
676	static void
677	set_mem_fault_trap(enable)
678	int enable;
679	{
680	extern void fltr_set_mem_err();
681	mem_err = 0;
682
683	if (enable)
684	exceptionHandler(0x29, fltr_set_mem_err);
685	else
686	exceptionHandler(0x29, trap_low);
687	}
688
689	asm ("
690	.text
691	.align 4
692
693	_dummy_hw_breakpoint:
694	jmpl %l2, %g0
695	rett %l2+4
696	nop
697	nop
698	");
699
700	static void
701	set_hw_breakpoint_trap(enable)
702	int enable;
703	{
704	extern void dummy_hw_breakpoint();
705
706	if (enable)
707	exceptionHandler(255, dummy_hw_breakpoint);
708	else
709	exceptionHandler(255, trap_low);
710	}
711
712	static void
713	get_in_break_mode()
714	{
715	#if 0
716	int x;
717	mesg("get_in_break_mode, sp = ");
718	phex(&x);
719	#endif
720	set_hw_breakpoint_trap(1);
721
722	asm("
723	sethi %hi(0xff10), %l4
724	or %l4, %lo(0xff10), %l4
725	sta %g0, [%l4]0x1
726	nop
727	nop
728	nop
729	");
730
731	set_hw_breakpoint_trap(0);
732	}
733
734	/* Convert the SPARC hardware trap type code to a unix signal number. */
735
736	static int
737	computeSignal(tt)
738	int tt;
739	{
740	struct hard_trap_info *ht;
741
742	for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
743	if (ht->tt == tt)
744	return ht->signo;
745
746	return SIGHUP; /* default for things we don't know about */
747	}
748
749	/*
750	* While we find nice hex chars, build an int.
751	* Return number of chars processed.
752	*/
753
754	static int
755	hexToInt(char *ptr, int intValue)
756	{
757	int numChars = 0;
758	int hexValue;
759
760	*intValue = 0;
761
762	while (**ptr)
763	{
764	hexValue = hex(**ptr);
765	if (hexValue < 0)
766	break;
767
768	intValue = (intValue << 4) \| hexValue;
769	numChars ++;
770
771	(*ptr)++;
772	}
773
774	return (numChars);
775	}
776
777	/*
778	* This function does all command procesing for interfacing to gdb. It
779	* returns 1 if you should skip the instruction at the trap address, 0
780	* otherwise.
781	*/
782
783	static void
784	handle_exception (registers)
785	unsigned long *registers;
786	{
787	int tt; /* Trap type */
788	int sigval;
789	int addr;
790	int length;
791	char *ptr;
792	unsigned long *sp;
793	unsigned long dsr;
794
795	/* First, we must force all of the windows to be spilled out */
796
797	asm("
798	! Ugh. sparclet has broken save
799	!save %sp, -64, %sp
800	save
801	add %fp,-64,%sp
802	!save %sp, -64, %sp
803	save
804	add %fp,-64,%sp
805	!save %sp, -64, %sp
806	save
807	add %fp,-64,%sp
808	!save %sp, -64, %sp
809	save
810	add %fp,-64,%sp
811	!save %sp, -64, %sp
812	save
813	add %fp,-64,%sp
814	!save %sp, -64, %sp
815	save
816	add %fp,-64,%sp
817	!save %sp, -64, %sp
818	save
819	add %fp,-64,%sp
820	!save %sp, -64, %sp
821	save
822	add %fp,-64,%sp
823	restore
824	restore
825	restore
826	restore
827	restore
828	restore
829	restore
830	restore
831	");
832
833	if (registers[PC] == (unsigned long)breakinst)
834	{
835	registers[PC] = registers[NPC];
836	registers[NPC] += 4;
837	}
838	sp = (unsigned long *)registers[SP];
839
840	tt = (registers[TBR] >> 4) & 0xff;
841
842	/* reply to host that an exception has occurred */
843	sigval = computeSignal(tt);
844	ptr = remcomOutBuffer;
845
846	*ptr++ = 'T';
847	*ptr++ = hexchars[sigval >> 4];
848	*ptr++ = hexchars[sigval & 0xf];
849
850	*ptr++ = hexchars[PC >> 4];
851	*ptr++ = hexchars[PC & 0xf];
852	*ptr++ = ':';
853	ptr = mem2hex((char *)&registers[PC], ptr, 4, 0);
854	*ptr++ = ';';
855
856	*ptr++ = hexchars[FP >> 4];
857	*ptr++ = hexchars[FP & 0xf];
858	*ptr++ = ':';
859	ptr = mem2hex(sp + 8 + 6, ptr, 4, 0); /* FP */
860	*ptr++ = ';';
861
862	*ptr++ = hexchars[SP >> 4];
863	*ptr++ = hexchars[SP & 0xf];
864	*ptr++ = ':';
865	ptr = mem2hex((char *)&sp, ptr, 4, 0);
866	*ptr++ = ';';
867
868	*ptr++ = hexchars[NPC >> 4];
869	*ptr++ = hexchars[NPC & 0xf];
870	*ptr++ = ':';
871	ptr = mem2hex((char *)&registers[NPC], ptr, 4, 0);
872	*ptr++ = ';';
873
874	*ptr++ = hexchars[O7 >> 4];
875	*ptr++ = hexchars[O7 & 0xf];
876	*ptr++ = ':';
877	ptr = mem2hex((char *)&registers[O7], ptr, 4, 0);
878	*ptr++ = ';';
879
880	*ptr++ = 0;
881
882	putpacket(remcomOutBuffer);
883
884	while (1)
885	{
886	remcomOutBuffer[0] = 0;
887
888	getpacket(remcomInBuffer);
889	switch (remcomInBuffer[0])
890	{
891	case '?':
892	remcomOutBuffer[0] = 'S';
893	remcomOutBuffer[1] = hexchars[sigval >> 4];
894	remcomOutBuffer[2] = hexchars[sigval & 0xf];
895	remcomOutBuffer[3] = 0;
896	break;
897
898	case 'd':
899	remote_debug = !(remote_debug); /* toggle debug flag */
900	break;
901
902	case 'g': /* return the value of the CPU registers */
903	{
904	ptr = remcomOutBuffer;
905	ptr = mem2hex((char )registers, ptr, 16 4, 0); /* G & O regs */
906	ptr = mem2hex(sp + 0, ptr, 16 * 4, 0); /* L & I regs */
907	memset(ptr, '0', 32 * 8); /* Floating point */
908	ptr = mem2hex((char *)&registers[Y],
909	ptr + 32 * 4 * 2,
910	8 * 4,
911	0); /* Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR */
912	ptr = mem2hex((char *)&registers[CCSR],
913	ptr,
914	8 * 4,
915	0); /* CCSR, CCPR, CCCRCR, CCOR, CCOBR, CCIBR, CCIR */
916	ptr = mem2hex((char *)&registers[ASR1],
917	ptr,
918	8 * 4,
919	0); /* ASR1,ASR15,ASR17,ASR18,ASR19,ASR20,ASR21,ASR22 */
920	#if 0 /* not implemented */
921	ptr = mem2hex((char *) &registers[AWR0],
922	ptr,
923	32 * 4,
924	0); /* Alternate Window Registers */
925	#endif
926	}
927	break;
928
929	case 'G': /* set value of all the CPU registers - return OK */
930	case 'P': /* set value of one CPU register - return OK */
931	{
932	unsigned long *newsp, psr;
933
934	psr = registers[PSR];
935
936	ptr = &remcomInBuffer[1];
937
938	if (remcomInBuffer[0] == 'P') /* do a single register */
939	{
940	int regno;
941
942	if (hexToInt (&ptr, &regno)
943	&& *ptr++ == '=')
944	if (regno >= L0 && regno <= I7)
945	hex2mem (ptr, sp + regno - L0, 4, 0);
946	else
947	hex2mem (ptr, (char *)&registers[regno], 4, 0);
948	else
949	{
950	strcpy (remcomOutBuffer, "P01");
951	break;
952	}
953	}
954	else
955	{
956	hex2mem(ptr, (char )registers, 16 4, 0); /* G & O regs */
957	hex2mem(ptr + 16 * 4 * 2, sp + 0, 16 * 4, 0); /* L & I regs */
958	hex2mem(ptr + 64 * 4 * 2, (char *)&registers[Y],
959	8 * 4, 0); /* Y,PSR,WIM,TBR,PC,NPC,FPSR,CPSR */
960	hex2mem(ptr + 72 * 4 * 2, (char *)&registers[CCSR],
961	8 * 4, 0); /* CCSR,CCPR,CCCRCR,CCOR,CCOBR,CCIBR,CCIR */
962	hex2mem(ptr + 80 * 4 * 2, (char *)&registers[ASR1],
963	8 * 4, 0); /* ASR1 ... ASR22 */
964	#if 0 /* not implemented */
965	hex2mem(ptr + 88 * 4 * 2, (char *)&registers[AWR0],
966	8 * 4, 0); /* Alternate Window Registers */
967	#endif
968	}
969	/* See if the stack pointer has moved. If so, then copy the saved
970	locals and ins to the new location. This keeps the window
971	overflow and underflow routines happy. */
972
973	newsp = (unsigned long *)registers[SP];
974	if (sp != newsp)
975	sp = memcpy(newsp, sp, 16 * 4);
976
977	/* Don't allow CWP to be modified. */
978
979	if (psr != registers[PSR])
980	registers[PSR] = (psr & 0x1f) \| (registers[PSR] & ~0x1f);
981
982	strcpy(remcomOutBuffer,"OK");
983	}
984	break;
985
986	case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */
987	/* Try to read %x,%x. */
988
989	ptr = &remcomInBuffer[1];
990
991	if (hexToInt(&ptr, &addr)
992	&& *ptr++ == ','
993	&& hexToInt(&ptr, &length))
994	{
995	if (mem2hex((char *)addr, remcomOutBuffer, length, 1))
996	break;
997
998	strcpy (remcomOutBuffer, "E03");
999	}
1000	else
1001	strcpy(remcomOutBuffer,"E01");
1002	break;
1003
1004	case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */
1005	/* Try to read '%x,%x:'. */
1006
1007	ptr = &remcomInBuffer[1];
1008
1009	if (hexToInt(&ptr, &addr)
1010	&& *ptr++ == ','
1011	&& hexToInt(&ptr, &length)
1012	&& *ptr++ == ':')
1013	{
1014	if (hex2mem(ptr, (char *)addr, length, 1))
1015	strcpy(remcomOutBuffer, "OK");
1016	else
1017	strcpy(remcomOutBuffer, "E03");
1018	}
1019	else
1020	strcpy(remcomOutBuffer, "E02");
1021	break;
1022
1023	case 'c': /* cAA..AA Continue at address AA..AA(optional) */
1024	/* try to read optional parameter, pc unchanged if no parm */
1025
1026	ptr = &remcomInBuffer[1];
1027	if (hexToInt(&ptr, &addr))
1028	{
1029	registers[PC] = addr;
1030	registers[NPC] = addr + 4;
1031	}
1032
1033	/* Need to flush the instruction cache here, as we may have deposited a
1034	breakpoint, and the icache probably has no way of knowing that a data ref to
1035	some location may have changed something that is in the instruction cache.
1036	*/
1037
1038	flush_i_cache();
1039	return;
1040
1041	/* kill the program */
1042	case 'k' : /* do nothing */
1043	break;
1044	#if 0
1045	case 't': /* Test feature */
1046	asm (" std %f30,[%sp]");
1047	break;
1048	#endif
1049	case 'r': /* Reset */
1050	asm ("call 0
1051	nop ");
1052	break;
1053
1054	#if 0
1055	Disabled until we can unscrew this properly
1056
1057	case 'b': /* bBB... Set baud rate to BB... */
1058	{
1059	int baudrate;
1060	extern void set_timer_3();
1061
1062	ptr = &remcomInBuffer[1];
1063	if (!hexToInt(&ptr, &baudrate))
1064	{
1065	strcpy(remcomOutBuffer,"B01");
1066	break;
1067	}
1068
1069	/* Convert baud rate to uart clock divider */
1070	switch (baudrate)
1071	{
1072	case 38400:
1073	baudrate = 16;
1074	break;
1075	case 19200:
1076	baudrate = 33;
1077	break;
1078	case 9600:
1079	baudrate = 65;
1080	break;
1081	default:
1082	strcpy(remcomOutBuffer,"B02");
1083	goto x1;
1084	}
1085
1086	putpacket("OK"); /* Ack before changing speed */
1087	set_timer_3(baudrate); /* Set it */
1088	}
1089	x1: break;
1090	#endif
1091	} /* switch */
1092
1093	/* reply to the request */
1094	putpacket(remcomOutBuffer);
1095	}
1096	}
1097
1098	/* This function will generate a breakpoint exception. It is used at the
1099	beginning of a program to sync up with a debugger and can be used
1100	otherwise as a quick means to stop program execution and "break" into
1101	the debugger. */
1102
1103	void
1104	breakpoint()
1105	{
1106	if (!initialized)
1107	return;
1108
1109	asm(" .globl _breakinst
1110
1111	_breakinst: ta 1
1112	");
1113	}
1114
1115	static void
1116	hw_breakpoint()
1117	{
1118	asm("
1119	ta 127
1120	");
1121	}
1122
1123	#if 0 /* experimental and never finished, left here for reference */
1124	static void
1125	splet_temp(void)
1126	{
1127	asm(" sub %sp,(16+1+6+1+121)*4,%sp ! Make room for input & locals
1128	! + hidden arg + arg spill
1129	! + doubleword alignment
1130	! + registers[121]
1131
1132	! Leave a trail of breadcrumbs! (save register save area for debugging)
1133	mov %sp, %l0
1134	add %l0, 24*4, %l0
1135	sethi %hi(_debug_registers), %l1
1136	st %l0, [%lo(_debug_registers) + %l1]
1137
1138	! Save the Alternate Register Set: (not implemented yet)
1139	! To save the Alternate Register set, we must:
1140	! 1) Save the current SP in some global location.
1141	! 2) Swap the register sets.
1142	! 3) Save the Alternate SP in the Y register
1143	! 4) Fetch the SP that we saved in step 1.
1144	! 5) Use that to save the rest of the regs (not forgetting ASP in Y)
1145	! 6) Restore the Alternate SP from Y
1146	! 7) Swap the registers back.
1147
1148	! 1) Copy the current stack pointer to global _SAVED_STACK_POINTER:
1149	sethi %hi(_saved_stack_pointer), %l0
1150	st %sp, [%lo(_saved_stack_pointer) + %l0]
1151
1152	! 2) Swap the register sets:
1153	mov %psr, %l1
1154	sethi %hi(0x10000), %l2
1155	xor %l1, %l2, %l1
1156	mov %l1, %psr
1157	nop ! 3 nops after write to %psr (needed?)
1158	nop
1159	nop
1160
1161	! 3) Save Alternate L0 in Y
1162	wr %l0, 0, %y
1163
1164	! 4) Load former SP into alternate SP, using L0
1165	sethi %hi(_saved_stack_pointer), %l0
1166	or %lo(_saved_stack_pointer), %l0, %l0
1167	swap [%l0], %sp
1168
1169	! 4.5) Restore alternate L0
1170	rd %y, %l0
1171
1172	! 5) Save the Alternate Window Registers
1173	st %r0, [%sp + (24 + 88) * 4] ! AWR0
1174	st %r1, [%sp + (24 + 89) * 4] ! AWR1
1175	st %r2, [%sp + (24 + 90) * 4] ! AWR2
1176	st %r3, [%sp + (24 + 91) * 4] ! AWR3
1177	st %r4, [%sp + (24 + 92) * 4] ! AWR4
1178	st %r5, [%sp + (24 + 93) * 4] ! AWR5
1179	st %r6, [%sp + (24 + 94) * 4] ! AWR6
1180	st %r7, [%sp + (24 + 95) * 4] ! AWR7
1181	st %r8, [%sp + (24 + 96) * 4] ! AWR8
1182	st %r9, [%sp + (24 + 97) * 4] ! AWR9
1183	st %r10, [%sp + (24 + 98) * 4] ! AWR10
1184	st %r11, [%sp + (24 + 99) * 4] ! AWR11
1185	st %r12, [%sp + (24 + 100) * 4] ! AWR12
1186	st %r13, [%sp + (24 + 101) * 4] ! AWR13
1187	! st %r14, [%sp + (24 + 102) * 4] ! AWR14 (SP)
1188	st %r15, [%sp + (24 + 103) * 4] ! AWR15
1189	st %r16, [%sp + (24 + 104) * 4] ! AWR16
1190	st %r17, [%sp + (24 + 105) * 4] ! AWR17
1191	st %r18, [%sp + (24 + 106) * 4] ! AWR18
1192	st %r19, [%sp + (24 + 107) * 4] ! AWR19
1193	st %r20, [%sp + (24 + 108) * 4] ! AWR20
1194	st %r21, [%sp + (24 + 109) * 4] ! AWR21
1195	st %r22, [%sp + (24 + 110) * 4] ! AWR22
1196	st %r23, [%sp + (24 + 111) * 4] ! AWR23
1197	st %r24, [%sp + (24 + 112) * 4] ! AWR24
1198	st %r25, [%sp + (24 + 113) * 4] ! AWR25
1199	st %r26, [%sp + (24 + 114) * 4] ! AWR26
1200	st %r27, [%sp + (24 + 115) * 4] ! AWR27
1201	st %r28, [%sp + (24 + 116) * 4] ! AWR28
1202	st %r29, [%sp + (24 + 117) * 4] ! AWR29
1203	st %r30, [%sp + (24 + 118) * 4] ! AWR30
1204	st %r31, [%sp + (24 + 119) * 4] ! AWR21
1205
1206	! Get the Alternate PSR (I hope...)
1207
1208	rd %psr, %l2
1209	st %l2, [%sp + (24 + 120) * 4] ! APSR
1210
1211	! Don't forget the alternate stack pointer
1212
1213	rd %y, %l3
1214	st %l3, [%sp + (24 + 102) * 4] ! AWR14 (SP)
1215
1216	! 6) Restore the Alternate SP (saved in Y)
1217
1218	rd %y, %o6
1219
1220
1221	! 7) Swap the registers back:
1222
1223	mov %psr, %l1
1224	sethi %hi(0x10000), %l2
1225	xor %l1, %l2, %l1
1226	mov %l1, %psr
1227	nop ! 3 nops after write to %psr (needed?)
1228	nop
1229	nop
1230	");
1231	}
1232
1233	#endif

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source: trunk/libs/newlib/src/libgloss/sparc/sparclet-stub.c @ 444

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