xref: /openbmc/u-boot/arch/nds32/cpu/n1213/start.S (revision 78a88f79) 
1/* SPDX-License-Identifier: GPL-2.0+ */
2/*
3 *	Andesboot - Startup Code for Whitiger core
4 *
5 *	Copyright (C) 2006	Andes Technology Corporation
6 *	Copyright (C) 2006	Shawn Lin <nobuhiro@andestech.com>
7 *	Copyright (C) 2011	Macpaul Lin <macpaul@andestech.com>
8 *				Greentime Hu <greentime@andestech.com>
9 */
10
11.pic
12
13#include <asm-offsets.h>
14#include <config.h>
15#include <common.h>
16#include <asm/macro.h>
17
18/*
19 * Jump vector table for EVIC mode
20 */
21#define ENA_DCAC		2UL
22#define DIS_DCAC		~ENA_DCAC
23#define ICAC_MEM_KBF_ISET	(0x07)	 	! I Cache sets per way
24#define ICAC_MEM_KBF_IWAY	(0x07<<3)	! I cache ways
25#define ICAC_MEM_KBF_ISZ	(0x07<<6)	! I cache line size
26#define DCAC_MEM_KBF_DSET	(0x07)		! D Cache sets per way
27#define DCAC_MEM_KBF_DWAY	(0x07<<3)	! D cache ways
28#define DCAC_MEM_KBF_DSZ	(0x07<<6)	! D cache line size
29
30#define PSW			$ir0
31#define EIT_INTR_PSW		$ir1		! interruption $PSW
32#define EIT_PREV_IPSW		$ir2		! previous $IPSW
33#define EIT_IVB			$ir3		! intr vector base address
34#define EIT_EVA			$ir4		! MMU related Exception VA reg
35#define EIT_PREV_EVA		$ir5		! previous $eva
36#define EIT_ITYPE		$ir6		! interruption type
37#define EIT_PREV_ITYPE		$ir7		! prev intr type
38#define EIT_MACH_ERR		$ir8		! machine error log
39#define EIT_INTR_PC		$ir9		! Interruption PC
40#define EIT_PREV_IPC		$ir10		! previous $IPC
41#define EIT_OVL_INTR_PC		$ir11		! overflow interruption PC
42#define EIT_PREV_P0		$ir12		! prev $P0
43#define EIT_PREV_P1		$ir13		! prev $p1
44#define CR_ICAC_MEM		$cr1		! I-cache/memory config reg
45#define CR_DCAC_MEM		$cr2		! D-cache/memory config reg
46#define MR_CAC_CTL		$mr8
47
48.globl _start
49
50_start:	j	reset
51	j	tlb_fill
52	j	tlb_not_present
53	j	tlb_misc
54	j	tlb_vlpt_miss
55	j	machine_error
56	j	debug
57	j	general_exception
58	j	syscall
59	j	internal_interrupt		! H0I
60	j	internal_interrupt		! H1I
61	j	internal_interrupt		! H2I
62	j	internal_interrupt		! H3I
63	j	internal_interrupt		! H4I
64	j	internal_interrupt		! H5I
65	j	software_interrupt		! S0I
66
67	.balign 16
68
69/*
70 * Andesboot Startup Code (reset vector)
71 *
72 *	1.	bootstrap
73 *		1.1 reset - start of u-boot
74 *		1.2 to superuser mode - as is when reset
75 *		1.4 Do lowlevel_init
76 *			- (this will jump out to lowlevel_init.S in SoC)
77 *			- (lowlevel_init)
78 *		1.3 Turn off watchdog timer
79 *			- (this will jump out to watchdog.S in SoC)
80 *			- (turnoff_watchdog)
81 *	2.	Do critical init when reboot (not from mem)
82 *	3.	Relocate andesboot to ram
83 *	4.	Setup stack
84 *	5.	Jump to second stage (board_init_r)
85 */
86
87/* Note: TEXT_BASE is defined by the (board-dependent) linker script */
88.globl _TEXT_BASE
89_TEXT_BASE:
90	.word	CONFIG_SYS_TEXT_BASE
91
92/* IRQ stack memory (calculated at run-time) + 8 bytes */
93.globl IRQ_STACK_START_IN
94IRQ_STACK_START_IN:
95	.word 0x0badc0de
96
97/*
98 * The bootstrap code of nds32 core
99 */
100
101reset:
102
103/*
104 *  gp = ~0            for burn mode
105 *     = ~load_address for load mode
106 */
107reset_gp:
108	.relax_hint 0
109	sethi   $gp, hi20(_GLOBAL_OFFSET_TABLE_-8)
110	.relax_hint 0
111	ori     $gp, $gp, lo12(_GLOBAL_OFFSET_TABLE_-4)
112	add5.pc $gp
113
114set_ivb:
115	li	$r0, 0x0
116	/* turn on BTB */
117	mtsr	$r0, $misc_ctl
118	/* set IVIC, vector size: 4 bytes, base: 0x0 */
119	mtsr	$r0, $ivb
120/*
121 * MMU_CTL NTC0 Non-cacheable
122 */
123	li	$r0, ~0x6
124	mfsr	$r1, $mr0
125	and	$r1, $r1, $r0
126	mtsr	$r1, $mr0
127
128	li	$r0, ~0x3
129	mfsr	$r1, $mr8
130	and	$r1, $r1, $r0
131	mtsr	$r1, $mr8
132#if (!defined(CONFIG_SYS_ICACHE_OFF) || !defined(CONFIG_SYS_DCACHE_OFF))
133/*
134 * MMU_CTL NTC0 Cacheable/Write-Back
135 */
136	li	$r0, 0x4
137	mfsr	$r1, $mr0
138	or	$r1, $r1, $r0
139	mtsr	$r1, $mr0
140#endif
141
142#ifndef CONFIG_SYS_DCACHE_OFF
143#ifdef CONFIG_ARCH_MAP_SYSMEM
144/*
145 * MMU_CTL NTC1 Non-cacheable
146 */
147	li	$r0, ~0x18
148	mfsr	$r1, $mr0
149	and	$r1, $r1, $r0
150	mtsr	$r1, $mr0
151/*
152 * MMU_CTL NTM1 mapping for partition 0
153 */
154	li	$r0, ~0x6000
155	mfsr	$r1, $mr0
156	and	$r1, $r1, $r0
157	mtsr	$r1, $mr0
158#endif
159#endif
160
161#if !defined(CONFIG_SYS_ICACHE_OFF)
162	li	$r0, 0x1
163	mfsr	$r1, $mr8
164	or	$r1, $r1, $r0
165	mtsr	$r1, $mr8
166#endif
167
168#if !defined(CONFIG_SYS_DCACHE_OFF)
169	li	$r0, 0x2
170	mfsr	$r1, $mr8
171	or	$r1, $r1, $r0
172	mtsr	$r1, $mr8
173#endif
174
175	jal mem_init
176
177#ifndef CONFIG_SKIP_LOWLEVEL_INIT
178	jal	lowlevel_init
179/*
180 *  gp = ~VMA          for burn mode
181 *     = ~load_address for load mode
182 */
183update_gp:
184	.relax_hint 0
185	sethi   $gp, hi20(_GLOBAL_OFFSET_TABLE_-8)
186	.relax_hint 0
187	ori     $gp, $gp, lo12(_GLOBAL_OFFSET_TABLE_-4)
188	add5.pc $gp
189#endif
190/*
191 *  do critical initializations first (shall be in short time)
192 *  do self_relocation ASAP.
193 */
194
195/*
196 * Set the N1213 (Whitiger) core to superuser mode
197 * According to spec, it is already when reset
198 */
199#ifndef CONFIG_SKIP_TRUNOFF_WATCHDOG
200	jal	turnoff_watchdog
201#endif
202
203/*
204 * Do CPU critical regs init only at reboot,
205 * not when booting from ram
206 */
207#ifdef CONFIG_INIT_CRITICAL
208	jal	cpu_init_crit		! Do CPU critical regs init
209#endif
210
211/*
212 * Set stackpointer in internal RAM to call board_init_f
213 * $sp must be 8-byte alignment for ABI compliance.
214 */
215call_board_init_f:
216	li		$sp, CONFIG_SYS_INIT_SP_ADDR
217	move	$r0, $sp
218	bal	board_init_f_alloc_reserve
219	move	$sp, $r0
220	bal	board_init_f_init_reserve
221#ifdef CONFIG_DEBUG_UART
222	bal	debug_uart_init
223#endif
224	li		$r0, 0x00000000
225#ifdef __PIC__
226#ifdef __NDS32_N1213_43U1H__
227/* __NDS32_N1213_43U1H__ implies NDS32 V0 ISA */
228	la	$r15, board_init_f	! store function address into $r15
229#endif
230#endif
231	j	board_init_f		! jump to board_init_f() in lib/board.c
232
233/*
234 * void relocate_code (addr_sp, gd, addr_moni)
235 *
236 * This "function" does not return, instead it continues in RAM
237 * after relocating the monitor code.
238 *
239 */
240
241/*
242 *  gp = ~RAM_SIZE - TEXT_SIZE for burn/load mode
243 */
244
245.globl	relocate_code
246relocate_code:
247	move	$r4, $r0		/* save addr_sp */
248	move	$r5, $r1		/* save addr of gd */
249	move	$r6, $r2		/* save addr of destination */
250
251/* Set up the stack */
252stack_setup:
253	move	$sp, $r4
254
255	la	$r0, _start@GOTOFF
256	beq	$r0, $r6, clear_bss	/* skip relocation */
257
258	la	 $r1, _end@GOTOFF
259	move $r2, $r6			/* r2 <- scratch for copy_loop */
260copy_loop:
261	lmw.bim	$r11, [$r0], $r18
262	smw.bim	$r11, [$r2], $r18
263	blt	$r0, $r1, copy_loop
264/*
265 * fix relocations related issues
266 */
267fix_relocations:
268	l.w	$r0, _TEXT_BASE@GOTOFF	/* r0 <- Text base */
269	sub	$r9, $r6, $r0			/* r9 <- relocation offset */
270
271	la  $r7, __rel_dyn_start@GOTOFF
272	add	$r7, $r7, $r9		/* r2 <- rel __got_start in RAM */
273	la  $r8, __rel_dyn_end@GOTOFF
274	add	$r8, $r8, $r9		/* r2 <- rel __got_start in RAM */
275	li  $r3, #0x2a /* R_NDS32_RELATIVE */
2761:
277	lmw.bim $r0, [$r7], $r2 /* r0,r1,r2 <- adr,type,addend */
278	bne $r1, $r3, 2f
279
280	add $r0, $r0, $r9
281	add $r2, $r2, $r9
282	sw  $r2, [$r0]
2832:
284	blt $r7, $r8, 1b
285
286clear_bss:
287	la	$r0, __bss_start@GOTOFF	/* r0 <- rel __bss_start in FLASH */
288	add	$r0, $r0, $r9		/* r0 <- rel __bss_start in FLASH */
289	la	$r1, __bss_end@GOTOFF		/* r1 <- rel __bss_end in RAM */
290	add	$r1, $r1, $r9		/* r0 <- rel __bss_end in RAM */
291	li	$r2, 0x00000000		/* clear */
292
293clbss_l:
294	sw	$r2, [$r0]		/* clear loop... */
295	addi	$r0, $r0, #4
296	bne	$r0, $r1, clbss_l
297
298/*
299 * We are done. Do not return, instead branch to second part of board
300 * initialization, now running from RAM.
301 */
302call_board_init_r:
303	bal invalidate_icache_all
304	bal flush_dcache_all
305	la	$r0, board_init_r@GOTOFF
306	move	$lp, $r0		/* offset of board_init_r() */
307	add	$lp, $lp, $r9		/* real address of board_init_r() */
308	/* setup parameters for board_init_r */
309	move	$r0, $r5		/* gd_t */
310	move	$r1, $r6		/* dest_addr */
311
312#ifdef __PIC__
313#ifdef __NDS32_N1213_43U1H__		/* NDS32 V0 ISA	*/
314	move	$r15, $lp		/* store function address into $r15 */
315#endif
316#endif
317
318	/* jump to it ... */
319	jr	$lp			/* jump to board_init_r() */
320
321/*
322 * Initialize CPU critical registers
323 *
324 *	1.	Setup control registers
325 *		1.1 Mask all IRQs
326 *		1.2 Flush cache and TLB
327 *		1.3 Disable MMU and cache
328 *	2.	Setup memory timing
329 */
330
331cpu_init_crit:
332
333	move	$r0, $lp		/* push	ra */
334
335	/* Disable Interrupts by clear GIE in $PSW reg */
336	setgie.d
337
338	/* Flush caches and TLB */
339	/* Invalidate caches */
340	jal	invalidate_icac
341	jal	invalidate_dcac
342
343	/* Flush TLB */
344	mfsr	$p0, $MMU_CFG
345	andi	$p0, $p0, 0x3			! MMPS
346	li	$p1, 0x2			! TLB MMU
347	bne	$p0, $p1, 1f
348	tlbop	flushall			! Flush TLB
349
3501:
351	! Disable MMU, Dcache
352	! Whitiger is MMU disabled when reset
353	! Disable the D$
354	mfsr	$p0, MR_CAC_CTL			! Get the $CACHE_CTL reg
355	li	$p1, DIS_DCAC
356	and	$p0, $p0, $p1			! Set DC_EN bit
357	mtsr	$p0, MR_CAC_CTL			! write back the $CACHE_CTL reg
358	isb
359
360	move	$lp, $r0
3612:
362	ret
363
364/*
365 * Invalidate I$
366 */
367invalidate_icac:
368	! read $cr1(I CAC/MEM cfg. reg.) configuration
369	mfsr	$t0, CR_ICAC_MEM
370
371	! Get the ISZ field
372	andi	$p0, $t0, ICAC_MEM_KBF_ISZ
373
374	! if $p0=0, then no I CAC existed
375	beqz	$p0, end_flush_icache
376
377	! get $p0 the index of I$ block
378	srli	$p0, $p0, 6
379
380	! $t1= bit width of I cache line size(ISZ)
381	addi	$t1, $p0, 2
382
383	li	$t4, 1
384	sll	$t5, $t4, $t1			! get $t5 cache line size
385	andi	$p1, $t0, ICAC_MEM_KBF_ISET	! get the ISET field
386	addi	$t2, $p1, 6			! $t2= bit width of ISET
387	andi	$p1, $t0, ICAC_MEM_KBF_IWAY	! get bitfield of Iway
388	srli	$p1, $p1, 3
389	addi	$p1, $p1, 1			! then $p1 is I way number
390	add	$t3, $t2, $t1			! SHIFT
391	sll	$p1, $p1, $t3			! GET the total cache size
392ICAC_LOOP:
393	sub	$p1, $p1, $t5
394	cctl	$p1, L1I_IX_INVAL
395	bnez	$p1, ICAC_LOOP
396end_flush_icache:
397	ret
398
399/*
400 * Invalidate D$
401 */
402invalidate_dcac:
403	! read $cr2(D CAC/MEM cfg. reg.) configuration
404	mfsr	$t0, CR_DCAC_MEM
405
406	! Get the DSZ field
407	andi	$p0, $t0, DCAC_MEM_KBF_DSZ
408
409	! if $p0=0, then no D CAC existed
410	beqz	$p0, end_flush_dcache
411
412	! get $p0 the index of D$ block
413	srli	$p0, $p0, 6
414
415	! $t1= bit width of D cache line size(DSZ)
416	addi	$t1, $p0, 2
417
418	li	$t4, 1
419	sll	$t5, $t4, $t1			! get $t5 cache line size
420	andi	$p1, $t0, DCAC_MEM_KBF_DSET	! get the DSET field
421	addi	$t2, $p1, 6			! $t2= bit width of DSET
422	andi	$p1, $t0, DCAC_MEM_KBF_DWAY	! get bitfield of D way
423	srli	$p1, $p1, 3
424	addi	$p1, $p1, 1			! then $p1 is D way number
425	add	$t3, $t2, $t1			! SHIFT
426	sll	$p1, $p1, $t3			! GET the total cache size
427DCAC_LOOP:
428	sub	$p1, $p1, $t5
429	cctl	$p1, L1D_IX_INVAL
430	bnez	$p1, DCAC_LOOP
431end_flush_dcache:
432	ret
433
434/*
435 * Interrupt handling
436 */
437
438/*
439 * exception handlers
440 */
441	.align	5
442
443.macro	SAVE_ALL
444	! FIXME: Other way to get PC?
445	! FIXME: Update according to the newest spec!!
4461:
447	li	 $r28, 1
448	push $r28
449	mfsr $r28, PSW			! $PSW
450	push $r28
451	mfsr $r28, EIT_EVA		! $ir1 $EVA
452	push $r28
453	mfsr $r28, EIT_ITYPE		! $ir2 $ITYPE
454	push $r28
455	mfsr $r28, EIT_MACH_ERR		! $ir3 Mach Error
456	push $r28
457	mfsr $r28, EIT_INTR_PSW		! $ir5 $IPSW
458	push $r28
459	mfsr $r28, EIT_PREV_IPSW	! $ir6 prev $IPSW
460	push $r28
461	mfsr $r28, EIT_PREV_EVA		! $ir7 prev $EVA
462	push $r28
463	mfsr $r28, EIT_PREV_ITYPE	! $ir8 prev $ITYPE
464	push $r28
465	mfsr $r28, EIT_INTR_PC		! $ir9 Interruption PC
466	push $r28
467	mfsr $r28, EIT_PREV_IPC		! $ir10 prev INTR_PC
468	push $r28
469	mfsr $r28, EIT_OVL_INTR_PC	! $ir11 Overflowed INTR_PC
470	push $r28
471	mfusr $r28, $d1.lo
472	push $r28
473	mfusr $r28, $d1.hi
474	push $r28
475	mfusr $r28, $d0.lo
476	push $r28
477	mfusr $r28, $d0.hi
478	push $r28
479	pushm $r0, $r30		! store $sp-$r31, ra-$r30, $gp-$r29, $r28-$fp
480	addi	$sp, $sp, -4	! make room for implicit pt_regs parameters
481.endm
482
483	.align	5
484tlb_fill:
485	SAVE_ALL
486	move	$r0, $sp			! To get the kernel stack
487	li	$r1, 1				! Determine interruption type
488	bal 	do_interruption
489
490	.align	5
491tlb_not_present:
492	SAVE_ALL
493	move	$r0, $sp			! To get the kernel stack
494	li	$r1, 2				! Determine interruption type
495	bal 	do_interruption
496
497	.align	5
498tlb_misc:
499	SAVE_ALL
500	move	$r0, $sp			! To get the kernel stack
501	li	$r1, 3				! Determine interruption type
502	bal 	do_interruption
503
504	.align	5
505tlb_vlpt_miss:
506	SAVE_ALL
507	move	$r0, $sp			! To get the kernel stack
508	li	$r1, 4				! Determine interruption type
509	bal	do_interruption
510
511	.align	5
512machine_error:
513	SAVE_ALL
514	move	$r0, $sp			! To get the kernel stack
515	li	$r1, 5				! Determine interruption type
516	bal	do_interruption
517
518	.align	5
519debug:
520	SAVE_ALL
521	move	$r0, $sp			! To get the kernel stack
522	li	$r1, 6				! Determine interruption type
523	bal	do_interruption
524
525	.align	5
526general_exception:
527	SAVE_ALL
528	move	$r0, $sp			! To get the kernel stack
529	li	$r1, 7				! Determine interruption type
530	bal	do_interruption
531
532	.align	5
533syscall:
534	SAVE_ALL
535	move	$r0, $sp			! To get the kernel stack
536	li	$r1, 8				! Determine interruption type
537	bal	do_interruption
538
539	.align	5
540internal_interrupt:
541	SAVE_ALL
542	move	$r0, $sp			! To get the kernel stack
543	li	$r1, 9				! Determine interruption type
544	bal	do_interruption
545
546	.align	5
547software_interrupt:
548	SAVE_ALL
549	move	$r0, $sp			! To get the kernel stack
550	li	$r1, 10				! Determine interruption type
551	bal	do_interruption
552
553	.align	5
554
555/*
556 * void reset_cpu(ulong addr);
557 * $r0: input address to jump to
558 */
559.globl reset_cpu
560reset_cpu:
561/* No need to disable MMU because we never enable it */
562
563	bal	invalidate_icac
564	bal	invalidate_dcac
565	mfsr	$p0, $MMU_CFG
566	andi	$p0, $p0, 0x3			! MMPS
567	li	$p1, 0x2			! TLB MMU
568	bne	$p0, $p1, 1f
569	tlbop	flushall			! Flush TLB
5701:
571	mfsr	$p0, MR_CAC_CTL			! Get the $CACHE_CTL reg
572	li	$p1, DIS_DCAC
573	and	$p0, $p0, $p1			! Clear the DC_EN bit
574	mtsr	$p0, MR_CAC_CTL			! Write back the $CACHE_CTL reg
575	br	$r0				! Jump to the input address
576