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start.S @ f50952c

Last change on this file since f50952c was f50952c, checked in by Joel Sherrill <joel.sherrill@…>, on 04/07/00 at 19:04:12
Patch from Charles-Antoine Gauthier <charles.gauthier@…> after feedback from Eric Norum <eric@…> on static and dynamic RAM sizing issues while still having as much shared code as possible across the m68k BSPs.
Property mode set to `100644`
File size: 10.1 KB

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1	/*
2	*
3	* This file contains the entry point for the application.
4	* It jumps to the BSP which is responsible for performing
5	* all initialization.
6	*
7	* COPYRIGHT (c) 1989-1999.
8	* On-Line Applications Research Corporation (OAR).
9	*
10	* The license and distribution terms for this file may in
11	* the file LICENSE in this distribution or at
12	* http://www.OARcorp.com/rtems/license.html.
13	*
14	* Based on the `gen68302' board support package, and covered by the
15	* original distribution terms.
16	*
17	* W. Eric Norum
18	* Saskatchewan Accelerator Laboratory
19	* University of Saskatchewan
20	* Saskatoon, Saskatchewan, CANADA
21	* eric@skatter.usask.ca
22	*
23	* $Id$
24	*/
25
26	#include "asm.h"
27
28	BEGIN_CODE
29	/*
30	* Step 1: Decide on Reset Stack Pointer and Initial Program Counter
31	*/
32	Entry:
33	.long m360+1024 \| 0: Initial SSP
34	.long start \| 1: Initial PC
35	.long _uhoh \| 2: Bus error
36	.long _uhoh \| 3: Address error
37	.long _uhoh \| 4: Illegal instruction
38	.long _uhoh \| 5: Zero division
39	.long _uhoh \| 6: CHK, CHK2 instruction
40	.long _uhoh \| 7: TRAPcc, TRAPV instructions
41	.long _uhoh \| 8: Privilege violation
42	.long _uhoh \| 9: Trace
43	.long _uhoh \| 10: Line 1010 emulator
44	.long _uhoh \| 11: Line 1111 emulator
45	.long _uhoh \| 12: Hardware breakpoint
46	.long _uhoh \| 13: Reserved for coprocessor violation
47	.long _uhoh \| 14: Format error
48	.long _uhoh \| 15: Uninitialized interrupt
49	.long _uhoh \| 16: Unassigned, reserved
50	.long _uhoh \| 17:
51	.long _uhoh \| 18:
52	.long _uhoh \| 19:
53	.long _uhoh \| 20:
54	.long _uhoh \| 21:
55	.long _uhoh \| 22:
56	.long _uhoh \| 23:
57	.long _spuriousInterrupt \| 24: Spurious interrupt
58	.long _uhoh \| 25: Level 1 interrupt autovector
59	.long _uhoh \| 26: Level 2 interrupt autovector
60	.long _uhoh \| 27: Level 3 interrupt autovector
61	.long _uhoh \| 28: Level 4 interrupt autovector
62	.long _uhoh \| 29: Level 5 interrupt autovector
63	.long _uhoh \| 30: Level 6 interrupt autovector
64	.long _uhoh \| 31: Level 7 interrupt autovector
65	.long _uhoh \| 32: Trap instruction (0-15)
66	.long _uhoh \| 33:
67	.long _uhoh \| 34:
68	.long _uhoh \| 35:
69	.long _uhoh \| 36:
70	.long _uhoh \| 37:
71	.long _uhoh \| 38:
72	.long _uhoh \| 39:
73	.long _uhoh \| 40:
74	.long _uhoh \| 41:
75	.long _uhoh \| 42:
76	.long _uhoh \| 43:
77	.long _uhoh \| 44:
78	.long _uhoh \| 45:
79	.long _uhoh \| 46:
80	.long _uhoh \| 47:
81	.long _uhoh \| 48: Reserved for coprocessor
82	.long _uhoh \| 49:
83	.long _uhoh \| 50:
84	.long _uhoh \| 51:
85	.long _uhoh \| 52:
86	.long _uhoh \| 53:
87	.long _uhoh \| 54:
88	.long _uhoh \| 55:
89	.long _uhoh \| 56:
90	.long _uhoh \| 57:
91	.long _uhoh \| 58:
92	.long _uhoh \| 59: Unassigned, reserved
93	.long _uhoh \| 60:
94	.long _uhoh \| 61:
95	.long _uhoh \| 62:
96	.long _uhoh \| 63:
97	.long _uhoh \| 64: User defined vectors (192)
98	.long _uhoh \| 65:
99	.long _uhoh \| 66:
100	.long _uhoh \| 67:
101	.long _uhoh \| 68:
102	.long _uhoh \| 69:
103	.long _uhoh \| 70:
104	.long _uhoh \| 71:
105	.long _uhoh \| 72:
106	.long _uhoh \| 73:
107	.long _uhoh \| 74:
108	.long _uhoh \| 75:
109	.long _uhoh \| 76:
110	.long _uhoh \| 77:
111	.long _uhoh \| 78:
112	.long _uhoh \| 79:
113	.long _uhoh \| 80:
114	.long _uhoh \| 81:
115	.long _uhoh \| 82:
116	.long _uhoh \| 83:
117	.long _uhoh \| 84:
118	.long _uhoh \| 85:
119	.long _uhoh \| 86:
120	.long _uhoh \| 87:
121	.long _uhoh \| 88:
122	.long _uhoh \| 89:
123	.long _uhoh \| 90:
124	.long _uhoh \| 91:
125	.long _uhoh \| 92:
126	.long _uhoh \| 93:
127	.long _uhoh \| 94:
128	.long _uhoh \| 95:
129	.long _uhoh \| 96:
130	.long _uhoh \| 97:
131	.long _uhoh \| 98:
132	.long _uhoh \| 99:
133	.long _uhoh \| 100:
134	.long _uhoh \| 101:
135	.long _uhoh \| 102:
136	.long _uhoh \| 103:
137	.long _uhoh \| 104:
138	.long _uhoh \| 105:
139	.long _uhoh \| 106:
140	.long _uhoh \| 107:
141	.long _uhoh \| 108:
142	.long _uhoh \| 109:
143	.long _uhoh \| 110:
144	.long _uhoh \| 111:
145	.long _uhoh \| 112:
146	.long _uhoh \| 113:
147	.long _uhoh \| 114:
148	.long _uhoh \| 115:
149	.long _uhoh \| 116:
150	.long _uhoh \| 117:
151	.long _uhoh \| 118:
152	.long _uhoh \| 119:
153	.long _uhoh \| 120:
154	.long _uhoh \| 121:
155	.long _uhoh \| 122:
156	.long _uhoh \| 123:
157	.long _uhoh \| 124:
158	.long _uhoh \| 125:
159	.long _uhoh \| 126:
160	.long _uhoh \| 127:
161	.long _uhoh \| 128:
162	.long _uhoh \| 129:
163	.long _uhoh \| 130:
164	.long _uhoh \| 131:
165	.long _uhoh \| 132:
166	.long _uhoh \| 133:
167	.long _uhoh \| 134:
168	.long _uhoh \| 135:
169	.long _uhoh \| 136:
170	.long _uhoh \| 137:
171	.long _uhoh \| 138:
172	.long _uhoh \| 139:
173	.long _uhoh \| 140:
174	.long _uhoh \| 141:
175	.long _uhoh \| 142:
176	.long _uhoh \| 143:
177	.long _uhoh \| 144:
178	.long _uhoh \| 145:
179	.long _uhoh \| 146:
180	.long _uhoh \| 147:
181	.long _uhoh \| 148:
182	.long _uhoh \| 149:
183	.long _uhoh \| 150:
184	.long _uhoh \| 151:
185	.long _uhoh \| 152:
186	.long _uhoh \| 153:
187	.long _uhoh \| 154:
188	.long _uhoh \| 155:
189	.long _uhoh \| 156:
190	.long _uhoh \| 157:
191	.long _uhoh \| 158:
192	.long _uhoh \| 159:
193	.long _uhoh \| 160:
194	.long _uhoh \| 161:
195	.long _uhoh \| 162:
196	.long _uhoh \| 163:
197	.long _uhoh \| 164:
198	.long _uhoh \| 165:
199	.long _uhoh \| 166:
200	.long _uhoh \| 167:
201	.long _uhoh \| 168:
202	.long _uhoh \| 169:
203	.long _uhoh \| 170:
204	.long _uhoh \| 171:
205	.long _uhoh \| 172:
206	.long _uhoh \| 173:
207	.long _uhoh \| 174:
208	.long _uhoh \| 175:
209	.long _uhoh \| 176:
210	.long _uhoh \| 177:
211	.long _uhoh \| 178:
212	.long _uhoh \| 179:
213	.long _uhoh \| 180:
214	.long _uhoh \| 181:
215	.long _uhoh \| 182:
216	.long _uhoh \| 183:
217	.long _uhoh \| 184:
218	.long _uhoh \| 185:
219	.long _uhoh \| 186:
220	.long _uhoh \| 187:
221	.long _uhoh \| 188:
222	.long _uhoh \| 189:
223	.long _uhoh \| 190:
224	.long _uhoh \| 191:
225	.long _uhoh \| 192:
226	.long _uhoh \| 193:
227	.long _uhoh \| 194:
228	.long _uhoh \| 195:
229	.long _uhoh \| 196:
230	.long _uhoh \| 197:
231	.long _uhoh \| 198:
232	.long _uhoh \| 199:
233	.long _uhoh \| 200:
234	.long _uhoh \| 201:
235	.long _uhoh \| 202:
236	.long _uhoh \| 203:
237	.long _uhoh \| 204:
238	.long _uhoh \| 205:
239	.long _uhoh \| 206:
240	.long _uhoh \| 207:
241	.long _uhoh \| 208:
242	.long _uhoh \| 209:
243	.long _uhoh \| 210:
244	.long _uhoh \| 211:
245	.long _uhoh \| 212:
246	.long _uhoh \| 213:
247	.long _uhoh \| 214:
248	.long _uhoh \| 215:
249	.long _uhoh \| 216:
250	.long _uhoh \| 217:
251	.long _uhoh \| 218:
252	.long _uhoh \| 219:
253	.long _uhoh \| 220:
254	.long _uhoh \| 221:
255	.long _uhoh \| 222:
256	.long _uhoh \| 223:
257	.long _uhoh \| 224:
258	.long _uhoh \| 225:
259	.long _uhoh \| 226:
260	.long _uhoh \| 227:
261	.long _uhoh \| 228:
262	.long _uhoh \| 229:
263	.long _uhoh \| 230:
264	.long _uhoh \| 231:
265	.long _uhoh \| 232:
266	.long _uhoh \| 233:
267	.long _uhoh \| 234:
268	.long _uhoh \| 235:
269	.long _uhoh \| 236:
270	.long _uhoh \| 237:
271	.long _uhoh \| 238:
272	.long _uhoh \| 239:
273	.long _uhoh \| 240:
274	.long _uhoh \| 241:
275	.long _uhoh \| 242:
276	.long _uhoh \| 243:
277	.long _uhoh \| 244:
278	.long _uhoh \| 245:
279	.long _uhoh \| 246:
280	.long _uhoh \| 247:
281	.long _uhoh \| 248:
282	.long _uhoh \| 249:
283	.long _uhoh \| 250:
284	.long _uhoh \| 251:
285	.long _uhoh \| 252:
286	.long _uhoh \| 253:
287	.long _uhoh \| 254:
288	.long _uhoh \| 255:
289
290	/*
291	* Default trap handler
292	* With an oscilloscope you can see AS* stop
293	*/
294	PUBLIC (_uhoh)
295	_uhoh: nop \| Leave spot for breakpoint
296	stop #0x2700 \| Stop with interrupts disabled
297	bra.l _uhoh \| Stuck forever
298
299	/*
300	* Log, but otherwise ignore, spurious interrupts
301	*/
302	PUBLIC (_spuriousInterrupt)
303	_spuriousInterrupt:
304	addql #1,_M68kSpuriousInterruptCount
305	rte
306
307	/*
308	* Place the low-order 3 octets of the board's ethernet address at
309	* a `well-known' fixed location relative to the startup location.
310	*/
311	.align 2
312	.word 0 \| Padding
313	ethernet_address_buffer:
314	.word 0x08F3 \| Default address
315	.word 0xDEAD
316	.word 0xCAFE
317
318	/*
319	* Initial PC
320	*/
321	.globl start
322	start:
323	/*
324	* Step 2: Stay in Supervisor Mode
325	*/
326	#if ( M68K_HAS_SEPARATE_STACKS == 1 )
327	oriw #0x3000,sr \| Switch to Master Stack Pointer
328	lea SYM(m360)+1024-64,a7 \| Put stack in dual-port ram
329	\| a little below the interrupt stack
330	#endif
331
332	/*
333	* Step 3: Write the VBR
334	*/
335	lea Entry,a0 \| Get base of vector table
336	movec a0,vbr \| Set up the VBR
337
338	/*
339	* Step 4: Write the MBAR
340	*/
341	movec dfc,d1 \| Save destination register
342	moveq #7,d0 \| CPU-space funcction code
343	movec d0,dfc \| Set destination function code register
344	movel #m360+0x101,d0 \| MBAR value (mask CPU space accesses)
345	movesl d0,0x3FF00 \| Set MBAR
346	movec d1,dfc \| Restore destination register
347
348	/*
349	* Step 5: Verify a dual-port RAM location
350	*/
351	lea m360,a0 \| Point a0 to first DPRAM location
352	moveb #0x33,d0 \| Set the test value
353	moveb d0,a0@ \| Set the memory location
354	cmpb a0@,d0 \| Does it read back?
355	bne _uhoh \| If not, bad news!
356	notb d0 \| Flip bits
357	moveb d0,a0@ \| Set the memory location
358	cmpb a0@,d0 \| Does it read back?
359	bne _uhoh \| If not, bad news!
360
361	/*
362	* Remaining steps are handled by C code
363	*/
364	jmp _Init68360 \| Start C code (which never returns)
365
366	/*
367	* Copy DATA segment, clear BSS segment, set up real stack, start C program.
368	* Assume that DATA and BSS sizes are multiples of 4.
369	*/
370	PUBLIC (_CopyDataClearBSSAndStart)
371	_CopyDataClearBSSAndStart:
372	lea _copy_start,a0 \| Get start of DATA in RAM
373	lea etext,a2 \| Get start of DATA in ROM
374	cmpl a0,a2 \| Are they the same?
375	beq.s NOCOPY \| Yes, no copy necessary
376	lea _copy_end,a1 \| Get end of DATA in RAM
377	bra.s COPYLOOPTEST \| Branch into copy loop
378	COPYLOOP:
379	movel a2@+,a0@+ \| Copy word from ROM to RAM
380	COPYLOOPTEST:
381	cmpl a1,a0 \| Done?
382	bcs.s COPYLOOP \| No, skip
383	NOCOPY:
384
385	lea _clear_start,a0 \| Get start of BSS
386	lea _clear_end,a1 \| Get end of BSS
387	clrl d0 \| Value to set
388	bra.s ZEROLOOPTEST \| Branch into clear loop
389	ZEROLOOP:
390	movel d0,a0@+ \| Clear a word
391	ZEROLOOPTEST:
392	cmpl a1,a0 \| Done?
393	bcs.s ZEROLOOP \| No, skip
394
395	movel 4(a7),_M68k_Ramsize \| Set RAM size
396
397	movel #_stack_init,a7 \| set master stack pointer
398	pea env \| envp
399	pea arg \| argv
400	movel d0,a7@- \| argc
401	jsr boot_card \| Call C main
402
403	PUBLIC (_mainDone)
404	_mainDone:
405	nop \| Leave spot for breakpoint
406	movew #1,a7 \| Force a double bus error
407	movel d0,a7@- \| This should cause a RESET
408	stop #0x2700 \| Stop with interrupts disabled
409	bra.l _mainDone \| Stuck forever
410
411	.align 2
412	END_CODE
413
414	BEGIN_DATA_DCL
415	.align 2
416	PUBLIC (environ)
417	environ:
418	.long env
419	PUBLIC (_M68kSpuriousInterruptCount)
420	_M68kSpuriousInterruptCount:
421	.long 0
422	END_DATA_DCL
423
424	BEGIN_BSS
425	env: .long 0
426	arg: .long 0
427	END_BSS
428
429	END

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