xref: /openbmc/u-boot/arch/nds32/cpu/n1213/start.S (revision 679590eb) 
1/*
2 *	Andesboot - Startup Code for Whitiger core
3 *
4 *	Copyright (C) 2006	Andes Technology Corporation
5 *	Copyright (C) 2006	Shawn Lin <nobuhiro@andestech.com>
6 *	Copyright (C) 2011	Macpaul Lin <macpaul@andestech.com>
7 *				Greentime Hu <greentime@andestech.com>
8 *
9 * SPDX-License-Identifier:	GPL-2.0+
10 */
11
12.pic
13
14#include <asm-offsets.h>
15#include <config.h>
16#include <common.h>
17#include <asm/macro.h>
18
19/*
20 * Jump vector table for EVIC mode
21 */
22#define ENA_DCAC		2UL
23#define DIS_DCAC		~ENA_DCAC
24#define ICAC_MEM_KBF_ISET	(0x07)	 	! I Cache sets per way
25#define ICAC_MEM_KBF_IWAY	(0x07<<3)	! I cache ways
26#define ICAC_MEM_KBF_ISZ	(0x07<<6)	! I cache line size
27#define DCAC_MEM_KBF_DSET	(0x07)		! D Cache sets per way
28#define DCAC_MEM_KBF_DWAY	(0x07<<3)	! D cache ways
29#define DCAC_MEM_KBF_DSZ	(0x07<<6)	! D cache line size
30
31#define PSW			$ir0
32#define EIT_INTR_PSW		$ir1		! interruption $PSW
33#define EIT_PREV_IPSW		$ir2		! previous $IPSW
34#define EIT_IVB			$ir3		! intr vector base address
35#define EIT_EVA			$ir4		! MMU related Exception VA reg
36#define EIT_PREV_EVA		$ir5		! previous $eva
37#define EIT_ITYPE		$ir6		! interruption type
38#define EIT_PREV_ITYPE		$ir7		! prev intr type
39#define EIT_MACH_ERR		$ir8		! machine error log
40#define EIT_INTR_PC		$ir9		! Interruption PC
41#define EIT_PREV_IPC		$ir10		! previous $IPC
42#define EIT_OVL_INTR_PC		$ir11		! overflow interruption PC
43#define EIT_PREV_P0		$ir12		! prev $P0
44#define EIT_PREV_P1		$ir13		! prev $p1
45#define CR_ICAC_MEM		$cr1		! I-cache/memory config reg
46#define CR_DCAC_MEM		$cr2		! D-cache/memory config reg
47#define MR_CAC_CTL		$mr8
48
49.globl _start
50
51_start:	j	reset
52	j	tlb_fill
53	j	tlb_not_present
54	j	tlb_misc
55	j	tlb_vlpt_miss
56	j	machine_error
57	j	debug
58	j	general_exception
59	j	syscall
60	j	internal_interrupt		! H0I
61	j	internal_interrupt		! H1I
62	j	internal_interrupt		! H2I
63	j	internal_interrupt		! H3I
64	j	internal_interrupt		! H4I
65	j	internal_interrupt		! H5I
66	j	software_interrupt		! S0I
67
68	.balign 16
69
70/*
71 * Andesboot Startup Code (reset vector)
72 *
73 *	1.	bootstrap
74 *		1.1 reset - start of u-boot
75 *		1.2 to superuser mode - as is when reset
76 *		1.4 Do lowlevel_init
77 *			- (this will jump out to lowlevel_init.S in SoC)
78 *			- (lowlevel_init)
79 *		1.3 Turn off watchdog timer
80 *			- (this will jump out to watchdog.S in SoC)
81 *			- (turnoff_watchdog)
82 *	2.	Do critical init when reboot (not from mem)
83 *	3.	Relocate andesboot to ram
84 *	4.	Setup stack
85 *	5.	Jump to second stage (board_init_r)
86 */
87
88/* Note: TEXT_BASE is defined by the (board-dependent) linker script */
89.globl _TEXT_BASE
90_TEXT_BASE:
91	.word	CONFIG_SYS_TEXT_BASE
92
93/* IRQ stack memory (calculated at run-time) + 8 bytes */
94.globl IRQ_STACK_START_IN
95IRQ_STACK_START_IN:
96	.word 0x0badc0de
97
98/*
99 * The bootstrap code of nds32 core
100 */
101
102reset:
103
104/*
105 *  gp = ~0            for burn mode
106 *     = ~load_address for load mode
107 */
108reset_gp:
109	.relax_hint 0
110	sethi   $gp, hi20(_GLOBAL_OFFSET_TABLE_-8)
111	.relax_hint 0
112	ori     $gp, $gp, lo12(_GLOBAL_OFFSET_TABLE_-4)
113	add5.pc $gp
114
115set_ivb:
116	li	$r0, 0x0
117	/* turn on BTB */
118	mtsr	$r0, $misc_ctl
119	/* set IVIC, vector size: 4 bytes, base: 0x0 */
120	mtsr	$r0, $ivb
121/*
122 * MMU_CTL NTC0 Cacheable/Write-Back
123 */
124	li	$r0, ~0x3
125	mfsr	$r1, $mr8
126	and	$r1, $r1, $r0
127	mtsr	$r1, $mr8
128#if (!defined(CONFIG_SYS_ICACHE_OFF) || !defined(CONFIG_SYS_DCACHE_OFF))
129	li	$r0, 0x4
130	mfsr	$r1, $mr0
131	or	$r1, $r1, $r0
132	mtsr	$r1, $mr0
133#endif
134
135#if !defined(CONFIG_SYS_ICACHE_OFF)
136	li	$r0, 0x1
137	mfsr	$r1, $mr8
138	or	$r1, $r1, $r0
139	mtsr	$r1, $mr8
140#endif
141
142#if !defined(CONFIG_SYS_DCACHE_OFF)
143	li	$r0, 0x2
144	mfsr	$r1, $mr8
145	or	$r1, $r1, $r0
146	mtsr	$r1, $mr8
147#endif
148
149	jal mem_init
150
151#ifndef CONFIG_SKIP_LOWLEVEL_INIT
152	jal	lowlevel_init
153/*
154 *  gp = ~VMA          for burn mode
155 *     = ~load_address for load mode
156 */
157update_gp:
158	.relax_hint 0
159	sethi   $gp, hi20(_GLOBAL_OFFSET_TABLE_-8)
160	.relax_hint 0
161	ori     $gp, $gp, lo12(_GLOBAL_OFFSET_TABLE_-4)
162	add5.pc $gp
163#endif
164/*
165 *  do critical initializations first (shall be in short time)
166 *  do self_relocation ASAP.
167 */
168
169/*
170 * Set the N1213 (Whitiger) core to superuser mode
171 * According to spec, it is already when reset
172 */
173#ifndef CONFIG_SKIP_TRUNOFF_WATCHDOG
174	jal	turnoff_watchdog
175#endif
176
177/*
178 * Do CPU critical regs init only at reboot,
179 * not when booting from ram
180 */
181#ifdef CONFIG_INIT_CRITICAL
182	jal	cpu_init_crit		! Do CPU critical regs init
183#endif
184
185/*
186 * Set stackpointer in internal RAM to call board_init_f
187 * $sp must be 8-byte alignment for ABI compliance.
188 */
189call_board_init_f:
190	li		$sp, CONFIG_SYS_INIT_SP_ADDR
191	move	$r0, $sp
192	bal	board_init_f_alloc_reserve
193	move	$sp, $r0
194	bal	board_init_f_init_reserve
195#ifdef CONFIG_DEBUG_UART
196	bal	debug_uart_init
197#endif
198	li		$r0, 0x00000000
199#ifdef __PIC__
200#ifdef __NDS32_N1213_43U1H__
201/* __NDS32_N1213_43U1H__ implies NDS32 V0 ISA */
202	la	$r15, board_init_f	! store function address into $r15
203#endif
204#endif
205	j	board_init_f		! jump to board_init_f() in lib/board.c
206
207/*
208 * void relocate_code (addr_sp, gd, addr_moni)
209 *
210 * This "function" does not return, instead it continues in RAM
211 * after relocating the monitor code.
212 *
213 */
214
215/*
216 *  gp = ~RAM_SIZE - TEXT_SIZE for burn/load mode
217 */
218
219.globl	relocate_code
220relocate_code:
221	move	$r4, $r0		/* save addr_sp */
222	move	$r5, $r1		/* save addr of gd */
223	move	$r6, $r2		/* save addr of destination */
224
225/* Set up the stack */
226stack_setup:
227	move	$sp, $r4
228
229	la	$r0, _start@GOTOFF
230	beq	$r0, $r6, clear_bss	/* skip relocation */
231
232	la	 $r1, _end@GOTOFF
233	move $r2, $r6			/* r2 <- scratch for copy_loop */
234copy_loop:
235	lmw.bim	$r11, [$r0], $r18
236	smw.bim	$r11, [$r2], $r18
237	blt	$r0, $r1, copy_loop
238/*
239 * fix relocations related issues
240 */
241fix_relocations:
242	l.w	$r0, _TEXT_BASE@GOTOFF	/* r0 <- Text base */
243	sub	$r9, $r6, $r0			/* r9 <- relocation offset */
244
245	la  $r7, __rel_dyn_start@GOTOFF
246	add	$r7, $r7, $r9		/* r2 <- rel __got_start in RAM */
247	la  $r8, __rel_dyn_end@GOTOFF
248	add	$r8, $r8, $r9		/* r2 <- rel __got_start in RAM */
249	li  $r3, #0x2a /* R_NDS32_RELATIVE */
2501:
251	lmw.bim $r0, [$r7], $r2 /* r0,r1,r2 <- adr,type,addend */
252	bne $r1, $r3, 2f
253
254	add $r0, $r0, $r9
255	add $r2, $r2, $r9
256	sw  $r2, [$r0]
2572:
258	blt $r7, $r8, 1b
259
260clear_bss:
261	la	$r0, __bss_start@GOTOFF	/* r0 <- rel __bss_start in FLASH */
262	add	$r0, $r0, $r9		/* r0 <- rel __bss_start in FLASH */
263	la	$r1, __bss_end@GOTOFF		/* r1 <- rel __bss_end in RAM */
264	add	$r1, $r1, $r9		/* r0 <- rel __bss_end in RAM */
265	li	$r2, 0x00000000		/* clear */
266
267clbss_l:
268	sw	$r2, [$r0]		/* clear loop... */
269	addi	$r0, $r0, #4
270	bne	$r0, $r1, clbss_l
271
272/*
273 * We are done. Do not return, instead branch to second part of board
274 * initialization, now running from RAM.
275 */
276call_board_init_r:
277	bal invalidate_icache_all
278	bal flush_dcache_all
279	la	$r0, board_init_r@GOTOFF
280	move	$lp, $r0		/* offset of board_init_r() */
281	add	$lp, $lp, $r9		/* real address of board_init_r() */
282	/* setup parameters for board_init_r */
283	move	$r0, $r5		/* gd_t */
284	move	$r1, $r6		/* dest_addr */
285
286#ifdef __PIC__
287#ifdef __NDS32_N1213_43U1H__		/* NDS32 V0 ISA	*/
288	move	$r15, $lp		/* store function address into $r15 */
289#endif
290#endif
291
292	/* jump to it ... */
293	jr	$lp			/* jump to board_init_r() */
294
295/*
296 * Initialize CPU critical registers
297 *
298 *	1.	Setup control registers
299 *		1.1 Mask all IRQs
300 *		1.2 Flush cache and TLB
301 *		1.3 Disable MMU and cache
302 *	2.	Setup memory timing
303 */
304
305cpu_init_crit:
306
307	move	$r0, $lp		/* push	ra */
308
309	/* Disable Interrupts by clear GIE in $PSW reg */
310	setgie.d
311
312	/* Flush caches and TLB */
313	/* Invalidate caches */
314	jal	invalidate_icac
315	jal	invalidate_dcac
316
317	/* Flush TLB */
318	mfsr	$p0, $MMU_CFG
319	andi	$p0, $p0, 0x3			! MMPS
320	li	$p1, 0x2			! TLB MMU
321	bne	$p0, $p1, 1f
322	tlbop	flushall			! Flush TLB
323
3241:
325	! Disable MMU, Dcache
326	! Whitiger is MMU disabled when reset
327	! Disable the D$
328	mfsr	$p0, MR_CAC_CTL			! Get the $CACHE_CTL reg
329	li	$p1, DIS_DCAC
330	and	$p0, $p0, $p1			! Set DC_EN bit
331	mtsr	$p0, MR_CAC_CTL			! write back the $CACHE_CTL reg
332	isb
333
334	move	$lp, $r0
3352:
336	ret
337
338/*
339 * Invalidate I$
340 */
341invalidate_icac:
342	! read $cr1(I CAC/MEM cfg. reg.) configuration
343	mfsr	$t0, CR_ICAC_MEM
344
345	! Get the ISZ field
346	andi	$p0, $t0, ICAC_MEM_KBF_ISZ
347
348	! if $p0=0, then no I CAC existed
349	beqz	$p0, end_flush_icache
350
351	! get $p0 the index of I$ block
352	srli	$p0, $p0, 6
353
354	! $t1= bit width of I cache line size(ISZ)
355	addi	$t1, $p0, 2
356
357	li	$t4, 1
358	sll	$t5, $t4, $t1			! get $t5 cache line size
359	andi	$p1, $t0, ICAC_MEM_KBF_ISET	! get the ISET field
360	addi	$t2, $p1, 6			! $t2= bit width of ISET
361	andi	$p1, $t0, ICAC_MEM_KBF_IWAY	! get bitfield of Iway
362	srli	$p1, $p1, 3
363	addi	$p1, $p1, 1			! then $p1 is I way number
364	add	$t3, $t2, $t1			! SHIFT
365	sll	$p1, $p1, $t3			! GET the total cache size
366ICAC_LOOP:
367	sub	$p1, $p1, $t5
368	cctl	$p1, L1I_IX_INVAL
369	bnez	$p1, ICAC_LOOP
370end_flush_icache:
371	ret
372
373/*
374 * Invalidate D$
375 */
376invalidate_dcac:
377	! read $cr2(D CAC/MEM cfg. reg.) configuration
378	mfsr	$t0, CR_DCAC_MEM
379
380	! Get the DSZ field
381	andi	$p0, $t0, DCAC_MEM_KBF_DSZ
382
383	! if $p0=0, then no D CAC existed
384	beqz	$p0, end_flush_dcache
385
386	! get $p0 the index of D$ block
387	srli	$p0, $p0, 6
388
389	! $t1= bit width of D cache line size(DSZ)
390	addi	$t1, $p0, 2
391
392	li	$t4, 1
393	sll	$t5, $t4, $t1			! get $t5 cache line size
394	andi	$p1, $t0, DCAC_MEM_KBF_DSET	! get the DSET field
395	addi	$t2, $p1, 6			! $t2= bit width of DSET
396	andi	$p1, $t0, DCAC_MEM_KBF_DWAY	! get bitfield of D way
397	srli	$p1, $p1, 3
398	addi	$p1, $p1, 1			! then $p1 is D way number
399	add	$t3, $t2, $t1			! SHIFT
400	sll	$p1, $p1, $t3			! GET the total cache size
401DCAC_LOOP:
402	sub	$p1, $p1, $t5
403	cctl	$p1, L1D_IX_INVAL
404	bnez	$p1, DCAC_LOOP
405end_flush_dcache:
406	ret
407
408/*
409 * Interrupt handling
410 */
411
412/*
413 * exception handlers
414 */
415	.align	5
416
417.macro	SAVE_ALL
418	! FIXME: Other way to get PC?
419	! FIXME: Update according to the newest spec!!
4201:
421	li	 $r28, 1
422	push $r28
423	mfsr $r28, PSW			! $PSW
424	push $r28
425	mfsr $r28, EIT_EVA		! $ir1 $EVA
426	push $r28
427	mfsr $r28, EIT_ITYPE		! $ir2 $ITYPE
428	push $r28
429	mfsr $r28, EIT_MACH_ERR		! $ir3 Mach Error
430	push $r28
431	mfsr $r28, EIT_INTR_PSW		! $ir5 $IPSW
432	push $r28
433	mfsr $r28, EIT_PREV_IPSW	! $ir6 prev $IPSW
434	push $r28
435	mfsr $r28, EIT_PREV_EVA		! $ir7 prev $EVA
436	push $r28
437	mfsr $r28, EIT_PREV_ITYPE	! $ir8 prev $ITYPE
438	push $r28
439	mfsr $r28, EIT_INTR_PC		! $ir9 Interruption PC
440	push $r28
441	mfsr $r28, EIT_PREV_IPC		! $ir10 prev INTR_PC
442	push $r28
443	mfsr $r28, EIT_OVL_INTR_PC	! $ir11 Overflowed INTR_PC
444	push $r28
445	mfusr $r28, $d1.lo
446	push $r28
447	mfusr $r28, $d1.hi
448	push $r28
449	mfusr $r28, $d0.lo
450	push $r28
451	mfusr $r28, $d0.hi
452	push $r28
453	pushm $r0, $r30		! store $sp-$r31, ra-$r30, $gp-$r29, $r28-$fp
454	addi	$sp, $sp, -4	! make room for implicit pt_regs parameters
455.endm
456
457	.align	5
458tlb_fill:
459	SAVE_ALL
460	move	$r0, $sp			! To get the kernel stack
461	li	$r1, 1				! Determine interruption type
462	bal 	do_interruption
463
464	.align	5
465tlb_not_present:
466	SAVE_ALL
467	move	$r0, $sp			! To get the kernel stack
468	li	$r1, 2				! Determine interruption type
469	bal 	do_interruption
470
471	.align	5
472tlb_misc:
473	SAVE_ALL
474	move	$r0, $sp			! To get the kernel stack
475	li	$r1, 3				! Determine interruption type
476	bal 	do_interruption
477
478	.align	5
479tlb_vlpt_miss:
480	SAVE_ALL
481	move	$r0, $sp			! To get the kernel stack
482	li	$r1, 4				! Determine interruption type
483	bal	do_interruption
484
485	.align	5
486machine_error:
487	SAVE_ALL
488	move	$r0, $sp			! To get the kernel stack
489	li	$r1, 5				! Determine interruption type
490	bal	do_interruption
491
492	.align	5
493debug:
494	SAVE_ALL
495	move	$r0, $sp			! To get the kernel stack
496	li	$r1, 6				! Determine interruption type
497	bal	do_interruption
498
499	.align	5
500general_exception:
501	SAVE_ALL
502	move	$r0, $sp			! To get the kernel stack
503	li	$r1, 7				! Determine interruption type
504	bal	do_interruption
505
506	.align	5
507syscall:
508	SAVE_ALL
509	move	$r0, $sp			! To get the kernel stack
510	li	$r1, 8				! Determine interruption type
511	bal	do_interruption
512
513	.align	5
514internal_interrupt:
515	SAVE_ALL
516	move	$r0, $sp			! To get the kernel stack
517	li	$r1, 9				! Determine interruption type
518	bal	do_interruption
519
520	.align	5
521software_interrupt:
522	SAVE_ALL
523	move	$r0, $sp			! To get the kernel stack
524	li	$r1, 10				! Determine interruption type
525	bal	do_interruption
526
527	.align	5
528
529/*
530 * void reset_cpu(ulong addr);
531 * $r0: input address to jump to
532 */
533.globl reset_cpu
534reset_cpu:
535/* No need to disable MMU because we never enable it */
536
537	bal	invalidate_icac
538	bal	invalidate_dcac
539	mfsr	$p0, $MMU_CFG
540	andi	$p0, $p0, 0x3			! MMPS
541	li	$p1, 0x2			! TLB MMU
542	bne	$p0, $p1, 1f
543	tlbop	flushall			! Flush TLB
5441:
545	mfsr	$p0, MR_CAC_CTL			! Get the $CACHE_CTL reg
546	li	$p1, DIS_DCAC
547	and	$p0, $p0, $p1			! Clear the DC_EN bit
548	mtsr	$p0, MR_CAC_CTL			! Write back the $CACHE_CTL reg
549	br	$r0				! Jump to the input address
550