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crt0.S @ 684

Last change on this file since 684 was 444, checked in by satin@…, 7 years ago
add newlib,libalmos-mkh, restructure shared_syscalls.h and mini-libc
File size: 20.0 KB

Line
1	/* crt0.S -- startup file for OpenRISC 1000.
2	*
3	* Copyright (c) 2011, 2014 Authors
4	*
5	* Contributor Julius Baxter <juliusbaxter@gmail.com>
6	* Contributor Stefan Wallentowitz <stefan.wallentowitz@tum.de>
7	*
8	* The authors hereby grant permission to use, copy, modify, distribute,
9	* and license this software and its documentation for any purpose, provided
10	* that existing copyright notices are retained in all copies and that this
11	* notice is included verbatim in any distributions. No written agreement,
12	* license, or royalty fee is required for any of the authorized uses.
13	* Modifications to this software may be copyrighted by their authors
14	* and need not follow the licensing terms described here, provided that
15	* the new terms are clearly indicated on the first page of each file where
16	* they apply.
17	*/
18
19	/* -------------------------------------------------------------------------- */
20	/* Coding convention:
21	Assembly is hard to read per se, so please follow the following coding
22	conventions to keep it consistent and ease reading:
23	* internal jump labels start with L, no identation
24	* assemble lines have one tab identation
25	* attributes (.section, .global, ..) are indented with one tab
26	* code is structured using tabs, i.e., use 'l.sw\t0(r1),r1' with a single
27	tab. libgloss assumes 8 space tab width, so that might look unstructured
28	with tab widths below 6. Nevertheless don't use spaces or two tabs.
29	* no space after comma
30	* use the defined macros if possible as they reduce errors
31	* use OR1K_INST with OR1K_DELAYED(_NOP)
32	* OR1K_DELAYED is multiline for better readability, the inner parts are
33	indented with another tab.
34	* COMMENT! Try to accompy every line with a meaningful comment. If possible
35	use pseudo code to describe the code. Also mention intentions and not only
36	the obvious things.. */
37	/* -------------------------------------------------------------------------- */
38
39	#include "newlib.h"
40	#include "include/or1k-asm.h"
41	#include "include/or1k-sprs.h"
42
43	/* -------------------------------------------------------------------------- */
44	// Stack definitions
45	/* -------------------------------------------------------------------------- */
46
47	// Stacks
48	// Memory layout:
49	// +--------------------+ <- board_mem_base+board_mem_size/exception_stack_top
50	// \| exception stack(s) \|
51	// +--------------------+ <- stack_top
52	// \| stack(s) \|
53	// +--------------------+ <- stack_bottom
54	// \| heap \|
55	// +--------------------+
56	// \| text, data, bss.. \|
57	// +--------------------+
58
59	// Reserved stack size
60	#define STACK_SIZE 8192
61
62	// Reserved stack size for exceptions (can usually be smaller than normal stack)
63	#define EXCEPTION_STACK_SIZE 8192
64
65	// Size of space required to store state
66	// This value must match that in the support library or1k_exception_handler
67	// function
68	#define EXCEPTION_STACK_FRAME 136
69
70	#define REDZONE 128
71
72	.extern _or1k_stack_top /* points to the next address after the stack */
73	.extern _or1k_stack_bottom /* points to the last address in the stack */
74	.extern _or1k_exception_stack_top
75	.extern _or1k_exception_stack_bottom
76	.extern _or1k_exception_level /* Nesting level of exceptions */
77
78	.section .data
79	.global _or1k_stack_size /* reserved stack size */
80	.global _or1k_exception_stack_size
81	.global _or1k_exception_level
82
83	_or1k_stack_size: .word STACK_SIZE
84	_or1k_exception_stack_size: .word EXCEPTION_STACK_SIZE
85
86	#ifdef __OR1K_MULTICORE__
87	.extern _or1k_stack_core
88	.extern _or1k_exception_stack_core
89	#endif
90
91	#define SHADOW_REG(x) (OR1K_SPR_SYS_GPR_BASE + 32 + x)
92
93	/* -------------------------------------------------------------------------- */
94	/*!Macro to handle exceptions.
95
96	Load NPC into r3, EPCR into r4
97	*/
98	/* -------------------------------------------------------------------------- */
99
100	#ifdef HAVE_INITFINI_ARRAY
101	#define _init __libc_init_array
102	#define _fini __libc_fini_array
103	#endif
104
105	#define GPR_BUF_OFFSET(x) (x << 2)
106
107	#ifndef __OR1K_MULTICORE__
108	#define CALL_EXCEPTION_HANDLER(id) \
109	/* Store current stack pointer to address 4 */ \
110	l.sw 0x4(r0),r1; \
111	/* Load address of exception nesting level */ \
112	l.movhi r1,hi(_or1k_exception_level); \
113	l.ori r1,r1,lo(_or1k_exception_level); \
114	/* Load the current nesting level */ \
115	l.lwz r1,0(r1); \
116	/* Set flag if this is the outer (first) exception */ \
117	l.sfeq r1,r0; \
118	/* Branch to the code for nested exceptions */ \
119	OR1K_DELAYED_NOP( \
120	OR1K_INST(l.bnf .Lnested_##id) \
121	); \
122	/* Load top of the exception stack */ \
123	l.movhi r1,hi(_or1k_exception_stack_top); \
124	l.ori r1,r1,lo(_or1k_exception_stack_top); \
125	OR1K_DELAYED( \
126	/* Load value from array to stack pointer */ \
127	OR1K_INST(l.lwz r1,0(r1)), \
128	/* and jump over the nested code */ \
129	OR1K_INST(l.j .Lnesting_done_##id) \
130	); \
131	.Lnested_##id: \
132	/* Load back the stack pointer */ \
133	l.lwz r1,0x4(r0); \
134	/* Add redzone, nesting needs this */ \
135	l.addi r1,r1,-REDZONE; \
136	.Lnesting_done_##id: \
137	/* Reserve red zone and context space */ \
138	l.addi r1,r1,-EXCEPTION_STACK_FRAME; \
139	/* Store GPR3 in context */ \
140	l.sw GPR_BUF_OFFSET(3)(r1),r3; \
141	/* Load back software's stack pointer */ \
142	l.lwz r3,0x4(r0); \
143	/* Store this in the context */ \
144	l.sw GPR_BUF_OFFSET(1)(r1),r3; \
145	/* Store GPR4 in the context */ \
146	l.sw GPR_BUF_OFFSET(4)(r1),r4; \
147	/* Load address of the exception level */ \
148	l.movhi r3,hi(_or1k_exception_level); \
149	l.ori r3,r3,lo(_or1k_exception_level); \
150	/* Load current value */ \
151	l.lwz r4,0(r3); \
152	/* Increment level */ \
153	l.addi r4,r4,1; \
154	/* Store back */ \
155	l.sw 0(r3),r4; \
156	/* Copy the current program counter as first */ \
157	/* argument for the exception handler. This */ \
158	/* is then used to determine the exception. */ \
159	l.mfspr r3,r0,OR1K_SPR_SYS_NPC_ADDR; \
160	OR1K_DELAYED( \
161	/* Copy program counter of exception as */ \
162	/* second argument to the exception handler */ \
163	OR1K_INST(l.mfspr r4,r0,OR1K_SPR_SYS_EPCR_BASE),\
164	/* Jump to exception handler. This will rfe */ \
165	OR1K_INST(l.j _or1k_exception_handler) \
166	)
167	#else
168	#define CALL_EXCEPTION_HANDLER(id) \
169	/* Store current stack pointer to shadow reg */ \
170	l.mtspr r0,r1,SHADOW_REG(1); \
171	/* Store current GPR3 for temporary use */ \
172	l.mtspr r0,r3,SHADOW_REG(2); \
173	/* Store current GPR2 for the level pointer */ \
174	l.mtspr r0,r4,SHADOW_REG(3); \
175	/* Load nesting level of exceptions */ \
176	l.movhi r4,hi(_or1k_exception_level); \
177	l.ori r4,r4,lo(_or1k_exception_level); \
178	/* Load array pointer */ \
179	l.lwz r4,0(r4); \
180	/* Get core id */ \
181	l.mfspr r3,r0,OR1K_SPR_SYS_COREID_ADDR; \
182	/* Generate offset */ \
183	l.slli r3,r3,2; \
184	/* Generate core nesting level address */ \
185	l.add r4,r4,r3; \
186	/* Load nesting level */ \
187	l.lwz r3,0(r4); \
188	/* Increment nesting level */ \
189	l.addi r3,r3,1; \
190	/* Write back nesting level */ \
191	l.sw 0(r4),r3; \
192	/* Set flag if this is the outer (first) exception */ \
193	l.sfeqi r3,1; \
194	/* Branch to the code for nested exceptions */ \
195	OR1K_DELAYED_NOP( \
196	OR1K_INST(l.bnf .Lnested_##id) \
197	); \
198	/* Load pointer to exception stack array */ \
199	l.movhi r1,hi(_or1k_exception_stack_core); \
200	l.ori r1,r1,lo(_or1k_exception_stack_core); \
201	l.lwz r1,0(r1); \
202	/* Get core id */ \
203	l.mfspr r3,r0,OR1K_SPR_SYS_COREID_ADDR; \
204	/* Calculate offset in array */ \
205	l.slli r3,r3,2; \
206	l.add r1,r1,r3; \
207	OR1K_DELAYED( \
208	/* Load value from array to stack pointer */ \
209	OR1K_INST(l.lwz r1,0(r1)), \
210	/* and jump over nested exception pointer */ \
211	OR1K_INST(l.j .Lnesting_done_##id) \
212	); \
213	.Lnested_##id: \
214	/* The stack pointer is still active */ \
215	/* Add redzone, nesting needs this */ \
216	l.addi r1,r1,-REDZONE; \
217	.Lnesting_done_##id: \
218	/* Reserve context space */ \
219	l.addi r1,r1,-EXCEPTION_STACK_FRAME; \
220	/* Load back software's stack pointer */ \
221	l.mfspr r3,r0,SHADOW_REG(1); \
222	/* Store this in the context */ \
223	l.sw GPR_BUF_OFFSET(1)(r1),r3; \
224	/* Load back GPR3 */ \
225	l.mfspr r3,r0,SHADOW_REG(2); \
226	/* Store this in the context */ \
227	l.sw GPR_BUF_OFFSET(3)(r1),r3; \
228	/* Load back GPR4 */ \
229	l.mfspr r4,r0,SHADOW_REG(3); \
230	/* Store GPR4 in the context */ \
231	l.sw GPR_BUF_OFFSET(4)(r1),r4; \
232	/* Copy the current program counter as first */ \
233	/* argument for the exception handler. This */ \
234	/* is then used to determine the exception. */ \
235	l.mfspr r3,r0,OR1K_SPR_SYS_NPC_ADDR; \
236	OR1K_DELAYED( \
237	/* Copy program counter of exception as */ \
238	/* second argument to the exception handler */ \
239	OR1K_INST(l.mfspr r4,r0,OR1K_SPR_SYS_EPCR_BASE),\
240	/* Jump to exception handler. This will rfe */ \
241	OR1K_INST(l.j _or1k_exception_handler) \
242	)
243	#endif
244
245	/* -------------------------------------------------------------------------- */
246	/!Exception vectors /
247	/* -------------------------------------------------------------------------- */
248	.section .vectors,"ax"
249
250	/* 0x100: RESET exception */
251	.org 0x100
252	_or1k_reset:
253	l.movhi r0,0
254	#ifdef __OR1K_MULTICORE__
255	// This is a hack that relies on the fact, that all cores start at the
256	// same time and they are similarily fast
257	l.sw 0x4(r0),r0
258	// Similarly, we use address 8 to signal how many cores have exit'ed
259	l.sw 0x8(r0),r0
260	#endif
261	l.movhi r1,0
262	l.movhi r2,0
263	l.movhi r3,0
264	l.movhi r4,0
265	l.movhi r5,0
266	l.movhi r6,0
267	l.movhi r7,0
268	l.movhi r8,0
269	l.movhi r9,0
270	l.movhi r10,0
271	l.movhi r11,0
272	l.movhi r12,0
273	l.movhi r13,0
274	l.movhi r14,0
275	l.movhi r15,0
276	l.movhi r16,0
277	l.movhi r17,0
278	l.movhi r18,0
279	l.movhi r19,0
280	l.movhi r20,0
281	l.movhi r21,0
282	l.movhi r22,0
283	l.movhi r23,0
284	l.movhi r24,0
285	l.movhi r25,0
286	l.movhi r26,0
287	l.movhi r27,0
288	l.movhi r28,0
289	l.movhi r29,0
290	l.movhi r30,0
291	l.movhi r31,0
292
293	/* Clear status register, set supervisor mode */
294	l.ori r1,r0,OR1K_SPR_SYS_SR_SM_MASK
295	l.mtspr r0,r1,OR1K_SPR_SYS_SR_ADDR
296	/* Clear timer mode register*/
297	l.mtspr r0,r0,OR1K_SPR_TICK_TTMR_ADDR
298	/* Jump to program initialisation code */
299	LOAD_SYMBOL_2_GPR(r4, _or1k_start)
300	OR1K_DELAYED_NOP(OR1K_INST(l.jr r4))
301
302	.org 0x200
303	CALL_EXCEPTION_HANDLER(2)
304
305	/* 0x300: Data Page Fault exception */
306	.org 0x300
307	CALL_EXCEPTION_HANDLER(3)
308
309	/* 0x400: Insn Page Fault exception */
310	.org 0x400
311	CALL_EXCEPTION_HANDLER(4)
312
313	/* 0x500: Timer exception */
314	.org 0x500
315	CALL_EXCEPTION_HANDLER(5)
316
317	/* 0x600: Aligment exception */
318	.org 0x600
319	CALL_EXCEPTION_HANDLER(6)
320
321	/* 0x700: Illegal insn exception */
322	.org 0x700
323	CALL_EXCEPTION_HANDLER(7)
324
325	/* 0x800: External interrupt exception */
326	.org 0x800
327	CALL_EXCEPTION_HANDLER(8)
328
329	/* 0x900: DTLB miss exception */
330	.org 0x900
331	CALL_EXCEPTION_HANDLER(9)
332
333	/* 0xa00: ITLB miss exception */
334	.org 0xa00
335	CALL_EXCEPTION_HANDLER(10)
336
337	/* 0xb00: Range exception */
338	.org 0xb00
339	CALL_EXCEPTION_HANDLER(11)
340
341	/* 0xc00: Syscall exception */
342	.org 0xc00
343	CALL_EXCEPTION_HANDLER(12)
344
345	/* 0xd00: Floating point exception */
346	.org 0xd00
347	CALL_EXCEPTION_HANDLER(13)
348
349	/* 0xe00: Trap exception */
350	.org 0xe00
351	CALL_EXCEPTION_HANDLER(14)
352
353	/* 0xf00: Reserved exceptions */
354	.org 0xf00
355	CALL_EXCEPTION_HANDLER(15)
356
357	.org 0x1000
358	CALL_EXCEPTION_HANDLER(16)
359
360	.org 0x1100
361	CALL_EXCEPTION_HANDLER(17)
362
363	.org 0x1200
364	CALL_EXCEPTION_HANDLER(18)
365
366	.org 0x1300
367	CALL_EXCEPTION_HANDLER(19)
368
369	.org 0x1400
370	CALL_EXCEPTION_HANDLER(20)
371
372	.org 0x1500
373	CALL_EXCEPTION_HANDLER(21)
374
375	.org 0x1600
376	CALL_EXCEPTION_HANDLER(22)
377
378	.org 0x1700
379	CALL_EXCEPTION_HANDLER(23)
380
381	.org 0x1800
382	CALL_EXCEPTION_HANDLER(24)
383
384	.org 0x1900
385	CALL_EXCEPTION_HANDLER(25)
386
387	.org 0x1a00
388	CALL_EXCEPTION_HANDLER(26)
389
390	.org 0x1b00
391	CALL_EXCEPTION_HANDLER(27)
392
393	.org 0x1c00
394	CALL_EXCEPTION_HANDLER(28)
395
396	.org 0x1d00
397	CALL_EXCEPTION_HANDLER(29)
398
399	.org 0x1e00
400	CALL_EXCEPTION_HANDLER(30)
401
402	.org 0x1f00
403	CALL_EXCEPTION_HANDLER(31)
404
405	/* Pad to the end */
406	.org 0x1ffc
407	l.nop
408
409	/* -------------------------------------------------------------------------- */
410	/*!Main entry point
411
412	This is the initialization code of the library. It performs these steps:
413
414	* Call early board initialization:
415	Before anything happened, the board support may do some very early
416	initialization. This is at maximum some very basic stuff that would
417	otherwise prevent the following code from functioning. Other initialization
418	of peripherals etc. is done later (before calling main).
419	See the description below and README.board for details.
420
421	* Initialize the stacks:
422	Two stacks are configured: The system stack is used by the software and
423	the exception stack is used when an exception occurs. We added this as
424	this should be flexible with respect to the usage of virtual memory.
425
426	* Activate the caches:
427	If available the caches are initiliazed and activated.
428
429	* Clear BSS:
430	The BSS are essentially the uninitialized C variables. They are set to 0
431	by default. This is performed by this function.
432
433	* Initialize the impure data structure:
434	Similarly, we need two library contexts, one for the normal software and
435	one that is used during exceptions. The impure data structure holds
436	the context information of the library. The called C function will setup
437	both data structures. There is furthermore a pointer to the currently
438	active impure data structure, which is initially set to the normal one.
439
440	* Initialize or1k support library reentrant data structures
441
442	* Initialize constructors:
443	Call the static and global constructors
444
445	* Set up destructors to call from exit
446	The library will call the function set via atexit() during exit(). We set
447	it to call the _fini function which performs destruction.
448
449	* Call board initialization:
450	The board initialization can perform board specific initializations such as
451	configuring peripherals etc.
452
453	* Jump to main
454	Call main with argc = 0 and *argv[] = 0
455
456	* Call exit after main returns
457	Now we call exit()
458
459	* Loop forever
460	We are dead.
461	*/
462
463	/* -------------------------------------------------------------------------- */
464	.section .text
465
466	/* Following externs from board-specific object passed at link time */
467	.extern _or1k_board_mem_base
468	.extern _or1k_board_mem_size
469	.extern _or1k_board_uart_base
470
471	/* The early board initialization may for example read the memory size and
472	set the mem_base and mem_size or do some preliminary board
473	initialization. As we do not have a stack at this time, the function may
474	not use the stack (and therefore be a or call a C function. But it can
475	safely use all registers.
476
477	We define a default implementation, which allows board files in C. As
478	described above, this can only be used in assembly (board_*.S) as at
479	the early stage not stack is available. A board that needs early
480	initialization can overwrite the function with .global _board_init_early.
481
482	Recommendation: Only use when you really need it! */
483	.weak _or1k_board_init_early
484	_or1k_board_init_early:
485	OR1K_DELAYED_NOP(OR1K_INST(l.jr r9))
486
487	/* The board initialization is then called after the C library and UART
488	are initialized. It can then be used to configure UART or other
489	devices before the actual main function is called. */
490	.extern _or1k_board_init
491
492	.global _or1k_start
493	.type _or1k_start,@function
494	_or1k_start:
495	/* It is good to initialize and enable the caches before we do anything,
496	otherwise the cores will continuously access the bus during the wait
497	time for the boot barrier (0x4).
498	Fortunately or1k_cache_init does not need a stack */
499	OR1K_DELAYED_NOP(OR1K_INST(l.jal _or1k_cache_init))
500
501	#ifdef __OR1K_MULTICORE__
502	// All but core 0 have to wait
503	l.mfspr r1, r0, OR1K_SPR_SYS_COREID_ADDR
504	l.sfeq r1, r0
505	OR1K_DELAYED_NOP(OR1K_INST(l.bf .Lcore0))
506	.Lspin:
507	/* r1 will be used by the other cores to check for the boot variable
508	Check if r1 is still zero, core 0 will set it to 1 once it booted
509	As the cache is already turned on, this will not create traffic on
510	the bus, but the change is snooped by cache coherency then */
511	l.lwz r1,0x4(r0)
512	l.sfeq r1, r0
513	OR1K_DELAYED_NOP(OR1K_INST(l.bf .Lspin))
514
515	/* Initialize core i stack */
516	// _or1k_stack_core is the array of stack pointers
517	LOAD_SYMBOL_2_GPR(r2,_or1k_stack_core)
518	// Load the base address
519	l.lwz r2,0(r2)
520	// Generate offset in array
521	l.mfspr r1,r0,OR1K_SPR_SYS_COREID_ADDR
522	l.slli r1,r1,2
523	// Add to array base
524	l.add r2,r2,r1
525	// Load pointer to the stack top and set frame pointer
526	l.lwz r1,0(r2)
527	l.or r2,r1,r1
528
529	// The slave cores are done, jump to main part
530	OR1K_DELAYED_NOP(OR1K_INST(l.j .Linit_done));
531
532	/* Only core 0 executes the initialization code */
533	.Lcore0:
534	#endif
535	/* Call early board initialization */
536	OR1K_DELAYED_NOP(OR1K_INST(l.jal _or1k_board_init_early))
537
538	/* Clear BSS */
539	.Lclear_bss:
540	LOAD_SYMBOL_2_GPR(r3,__bss_start)
541	LOAD_SYMBOL_2_GPR(r4,end)
542
543	.Lclear_bss_loop:
544	l.sw (0)(r3),r0
545	l.sfltu r3,r4
546	OR1K_DELAYED(
547	OR1K_INST(l.addi r3,r3,4),
548	OR1K_INST(l.bf .Lclear_bss_loop)
549	)
550
551	/* Initialise stack and frame pointer (set to same value) */
552	LOAD_SYMBOL_2_GPR(r1,_or1k_board_mem_base)
553	l.lwz r1,0(r1)
554	LOAD_SYMBOL_2_GPR(r2,_or1k_board_mem_size)
555	l.lwz r2,0(r2)
556	l.add r1,r1,r2
557
558	/* Store exception stack top address */
559	LOAD_SYMBOL_2_GPR(r3,_or1k_exception_stack_top)
560	l.sw 0(r3),r1
561
562	/* Store exception stack bottom address */
563	// calculate bottom address
564	// r3 = *exception stack size
565	LOAD_SYMBOL_2_GPR(r3,_or1k_exception_stack_size)
566	// r3 = exception stack size
567	l.lwz r3,0(r3)
568	#ifdef __OR1K_MULTICORE__
569	l.mfspr r4,r0,OR1K_SPR_SYS_NUMCORES_ADDR
570	l.mul r3,r4,r3
571	#endif
572	// r4 = exception stack top - exception stack size = exception stack bottom
573	l.sub r4,r1,r3
574	// r5 = *exception stack bottom
575	LOAD_SYMBOL_2_GPR(r5,_or1k_exception_stack_bottom)
576	// store
577	l.sw 0(r5),r4
578
579	// Move stack pointer accordingly
580	l.or r1,r0,r4
581	l.or r2,r1,r1
582
583	/* Store stack top address */
584	LOAD_SYMBOL_2_GPR(r3,_or1k_stack_top)
585	l.sw 0(r3),r1
586
587	/* Store stack bottom address */
588	// calculate bottom address
589	// r3 = stack size
590	LOAD_SYMBOL_2_GPR(r3,_or1k_stack_size)
591	l.lwz r3,0(r3)
592	#ifdef __OR1K_MULTICORE__
593	l.mfspr r4, r0, OR1K_SPR_SYS_NUMCORES_ADDR
594	l.mul r3, r4, r3
595	#endif
596	// r4 = stack top - stack size = stack bottom
597	// -> stack bottom
598	l.sub r4,r1,r3
599	// r5 = *exception stack bottom
600	LOAD_SYMBOL_2_GPR(r5,_or1k_stack_bottom)
601	// store to variable
602	l.sw 0(r5),r4
603
604	/* Reinitialize the or1k support library */
605	OR1K_DELAYED_NOP(OR1K_INST(l.jal _or1k_init))
606
607	/* Reinitialize the reentrancy structure */
608	OR1K_DELAYED_NOP(OR1K_INST(l.jal _or1k_libc_impure_init))
609
610	/* Call global and static constructors */
611	OR1K_DELAYED_NOP(OR1K_INST(l.jal _init))
612
613	/* Set up destructors to be called from exit if main ever returns */
614	l.movhi r3,hi(_fini)
615	OR1K_DELAYED(
616	OR1K_INST(l.ori r3,r3,lo(_fini)),
617	OR1K_INST(l.jal atexit)
618	)
619
620	/* Check if UART is to be initialised */
621	LOAD_SYMBOL_2_GPR(r4,_or1k_board_uart_base)
622	l.lwz r4,0(r4)
623	/* Is base set? If not, no UART */
624	l.sfne r4,r0
625	l.bnf .Lskip_uart
626	l.or r3,r0,r0
627	OR1K_DELAYED_NOP(OR1K_INST(l.jal _or1k_uart_init))
628
629	.Lskip_uart:
630	/* Board initialization */
631	OR1K_DELAYED_NOP(OR1K_INST(l.jal _or1k_board_init))
632
633	#ifdef __OR1K_MULTICORE__
634	// Start other cores
635	l.ori r3, r0, 1
636	l.sw 0x4(r0), r3
637	#endif
638
639	.Linit_done:
640	/* Jump to main program entry point (argc = argv = envp = 0) */
641	l.or r3,r0,r0
642	l.or r4,r0,r0
643	OR1K_DELAYED(
644	OR1K_INST(l.or r5,r0,r0),
645	OR1K_INST(l.jal main)
646	)
647
648	#ifdef __OR1K_MULTICORE__
649	.incrementexit:
650	/* Atomically increment number of finished cores */
651	l.lwa r3,0x8(r0)
652	l.addi r3,r3,1
653	l.swa 0x8(r0),r3
654	OR1K_DELAYED_NOP(OR1K_INST(l.bnf .incrementexit));
655	/* Compare to number of cores in this cluster */
656	l.mfspr r4,r0, OR1K_SPR_SYS_NUMCORES_ADDR
657	/* Compare to number of finished tasks */
658	l.sfeq r3,r4
659	/* Last core needs to desctruct library etc. */
660	OR1K_DELAYED_NOP(OR1K_INST(l.bf .exitcorelast));
661	OR1K_DELAYED(
662	OR1K_INST(l.addi r3,r11,0),
663	OR1K_INST(l.jal _exit)
664	)
665	.exitcorelast:
666	#endif
667	/* If program exits, call exit routine */
668	OR1K_DELAYED(
669	OR1K_INST(l.addi r3,r11,0),
670	OR1K_INST(l.jal exit)
671	)
672
673	/* Loop forever */
674	.Lloop_forever:
675	OR1K_DELAYED_NOP(OR1K_INST(l.j .Lloop_forever))
676
677	.size _or1k_start,.-_or1k_start

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