xref: /openbmc/u-boot/arch/mips/mach-jz47xx/start.S (revision dbb0696b)
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 *  Startup Code for MIPS32 XBURST CPU-core
4 *
5 *  Copyright (c) 2010 Xiangfu Liu <xiangfu@sharism.cc>
6 */
7
8#include <config.h>
9#include <asm/regdef.h>
10#include <asm/mipsregs.h>
11#include <asm/addrspace.h>
12#include <asm/cacheops.h>
13#include <asm/cache.h>
14#include <mach/jz4780.h>
15
16	.set noreorder
17
18	.globl _start
19	.text
20_start:
21#ifdef CONFIG_SPL_BUILD
22
23	/* magic value ("MSPL") */
24	.word 0x4d53504c
25
26	/* Invalidate BTB */
27	mfc0	t0, CP0_CONFIG, 7
28	nop
29	ori	t0, 2
30	mtc0	t0, CP0_CONFIG, 7
31	nop
32
33	/*
34	 * CU0=UM=EXL=IE=0, BEV=ERL=1, IP2~7=1
35	 */
36	li	t0, 0x0040FC04
37	mtc0	t0, CP0_STATUS
38
39	/* CAUSE register */
40	/* IV=1, use the specical interrupt vector (0x200) */
41	li	t1, 0x00800000
42	mtc0	t1, CP0_CAUSE
43
44#ifdef CONFIG_SOC_JZ4780
45	/* enable bridge radical mode */
46	la	t0, CPM_BASE
47	lw	t1, 0x24(t0)
48	ori	t1, t1, 0x22
49	sw	t1, 0x24(t0)
50#endif
51
52	/* Set up stack */
53	li	sp, CONFIG_SPL_STACK
54
55	b		board_init_f
56	 nop
57
58#ifdef CONFIG_SOC_JZ4780
59
60	.globl enable_caches
61	.ent enable_caches
62enable_caches:
63	mtc0	zero, CP0_TAGLO
64	mtc0	zero, CP0_TAGHI
65
66	li	t0, KSEG0
67	addu	t1, t0, CONFIG_SYS_DCACHE_SIZE
681:
69	cache	INDEX_STORE_TAG_D, 0(t0)
70	bne	t0, t1, 1b
71	addiu	t0, t0, CONFIG_SYS_CACHELINE_SIZE
72
73	li	t0, KSEG0
74	addu	t1, t0, CONFIG_SYS_ICACHE_SIZE
752:
76	cache	INDEX_STORE_TAG_I, 0(t0)
77	bne	t0, t1, 2b
78	addiu	t0, t0, CONFIG_SYS_CACHELINE_SIZE
79
80	/* Invalidate BTB */
81	mfc0	t0, CP0_CONFIG, 7
82	nop
83	ori	t0, 2
84	mtc0	t0, CP0_CONFIG, 7
85	nop
86
87	/* Enable caches */
88	li	t0, CONF_CM_CACHABLE_NONCOHERENT
89	mtc0	t0, CP0_CONFIG
90	nop
91
92	jr	ra
93	 nop
94
95	.end enable_caches
96
97#endif /* CONFIG_SOC_JZ4780 */
98#endif /* !CONFIG_SPL_BUILD */
99