xref: /OK3568_Linux_fs/u-boot/arch/arm/cpu/arm1136/start.S (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun/*
2*4882a593Smuzhiyun *  armboot - Startup Code for OMP2420/ARM1136 CPU-core
3*4882a593Smuzhiyun *
4*4882a593Smuzhiyun *  Copyright (c) 2004	Texas Instruments <r-woodruff2@ti.com>
5*4882a593Smuzhiyun *
6*4882a593Smuzhiyun *  Copyright (c) 2001	Marius Gröger <mag@sysgo.de>
7*4882a593Smuzhiyun *  Copyright (c) 2002	Alex Züpke <azu@sysgo.de>
8*4882a593Smuzhiyun *  Copyright (c) 2002	Gary Jennejohn <garyj@denx.de>
9*4882a593Smuzhiyun *  Copyright (c) 2003	Richard Woodruff <r-woodruff2@ti.com>
10*4882a593Smuzhiyun *  Copyright (c) 2003	Kshitij <kshitij@ti.com>
11*4882a593Smuzhiyun *
12*4882a593Smuzhiyun * SPDX-License-Identifier:	GPL-2.0+
13*4882a593Smuzhiyun */
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun#include <asm-offsets.h>
16*4882a593Smuzhiyun#include <config.h>
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun/*
19*4882a593Smuzhiyun *************************************************************************
20*4882a593Smuzhiyun *
21*4882a593Smuzhiyun * Startup Code (reset vector)
22*4882a593Smuzhiyun *
23*4882a593Smuzhiyun * do important init only if we don't start from memory!
24*4882a593Smuzhiyun * setup Memory and board specific bits prior to relocation.
25*4882a593Smuzhiyun * relocate armboot to ram
26*4882a593Smuzhiyun * setup stack
27*4882a593Smuzhiyun *
28*4882a593Smuzhiyun *************************************************************************
29*4882a593Smuzhiyun */
30*4882a593Smuzhiyun
31*4882a593Smuzhiyun	.globl	reset
32*4882a593Smuzhiyun
33*4882a593Smuzhiyunreset:
34*4882a593Smuzhiyun	/*
35*4882a593Smuzhiyun	 * set the cpu to SVC32 mode
36*4882a593Smuzhiyun	 */
37*4882a593Smuzhiyun	mrs	r0,cpsr
38*4882a593Smuzhiyun	bic	r0,r0,#0x1f
39*4882a593Smuzhiyun	orr	r0,r0,#0xd3
40*4882a593Smuzhiyun	msr	cpsr,r0
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun	/* the mask ROM code should have PLL and others stable */
43*4882a593Smuzhiyun#ifndef CONFIG_SKIP_LOWLEVEL_INIT
44*4882a593Smuzhiyun	bl  cpu_init_crit
45*4882a593Smuzhiyun#endif
46*4882a593Smuzhiyun
47*4882a593Smuzhiyun	bl	_main
48*4882a593Smuzhiyun
49*4882a593Smuzhiyun/*------------------------------------------------------------------------------*/
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun	.globl	c_runtime_cpu_setup
52*4882a593Smuzhiyunc_runtime_cpu_setup:
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun	bx	lr
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun/*
57*4882a593Smuzhiyun *************************************************************************
58*4882a593Smuzhiyun *
59*4882a593Smuzhiyun * CPU_init_critical registers
60*4882a593Smuzhiyun *
61*4882a593Smuzhiyun * setup important registers
62*4882a593Smuzhiyun * setup memory timing
63*4882a593Smuzhiyun *
64*4882a593Smuzhiyun *************************************************************************
65*4882a593Smuzhiyun */
66*4882a593Smuzhiyun#ifndef CONFIG_SKIP_LOWLEVEL_INIT
67*4882a593Smuzhiyuncpu_init_crit:
68*4882a593Smuzhiyun	/*
69*4882a593Smuzhiyun	 * flush v4 I/D caches
70*4882a593Smuzhiyun	 */
71*4882a593Smuzhiyun	mov	r0, #0
72*4882a593Smuzhiyun	mcr	p15, 0, r0, c7, c7, 0	/* Invalidate I+D+BTB caches */
73*4882a593Smuzhiyun	mcr	p15, 0, r0, c8, c7, 0	/* Invalidate Unified TLB */
74*4882a593Smuzhiyun
75*4882a593Smuzhiyun	/*
76*4882a593Smuzhiyun	 * disable MMU stuff and caches
77*4882a593Smuzhiyun	 */
78*4882a593Smuzhiyun	mrc	p15, 0, r0, c1, c0, 0
79*4882a593Smuzhiyun	bic	r0, r0, #0x00002300	@ clear bits 13, 9:8 (--V- --RS)
80*4882a593Smuzhiyun	bic	r0, r0, #0x00000087	@ clear bits 7, 2:0 (B--- -CAM)
81*4882a593Smuzhiyun	orr	r0, r0, #0x00000002	@ set bit 1 (A) Align
82*4882a593Smuzhiyun	orr	r0, r0, #0x00001000	@ set bit 12 (I) I-Cache
83*4882a593Smuzhiyun	mcr	p15, 0, r0, c1, c0, 0
84*4882a593Smuzhiyun
85*4882a593Smuzhiyun#ifndef CONFIG_SKIP_LOWLEVEL_INIT_ONLY
86*4882a593Smuzhiyun	/*
87*4882a593Smuzhiyun	 * Jump to board specific initialization... The Mask ROM will have already initialized
88*4882a593Smuzhiyun	 * basic memory.  Go here to bump up clock rate and handle wake up conditions.
89*4882a593Smuzhiyun	 */
90*4882a593Smuzhiyun	mov	ip, lr		/* persevere link reg across call */
91*4882a593Smuzhiyun	bl	lowlevel_init	/* go setup pll,mux,memory */
92*4882a593Smuzhiyun	mov	lr, ip		/* restore link */
93*4882a593Smuzhiyun#endif
94*4882a593Smuzhiyun	mov	pc, lr		/* back to my caller */
95*4882a593Smuzhiyun#endif /* CONFIG_SKIP_LOWLEVEL_INIT */
96