blob: 61982e38a1d4a017873b95ce69e7da262bedaa0d [file] [log] [blame]
Tom Rini10e47792018-05-06 17:58:06 -04001/* SPDX-License-Identifier: GPL-2.0+ */
Marek Vasut926227e2011-11-08 23:18:21 +00002/*
3 * armboot - Startup Code for ARM926EJS CPU-core
4 *
5 * Copyright (c) 2003 Texas Instruments
6 *
7 * ----- Adapted for OMAP1610 OMAP730 from ARM925t code ------
8 *
9 * Copyright (c) 2001 Marius Groger <mag@sysgo.de>
10 * Copyright (c) 2002 Alex Zupke <azu@sysgo.de>
11 * Copyright (c) 2002 Gary Jennejohn <garyj@denx.de>
12 * Copyright (c) 2003 Richard Woodruff <r-woodruff2@ti.com>
13 * Copyright (c) 2003 Kshitij <kshitij@ti.com>
14 * Copyright (c) 2010 Albert Aribaud <albert.u.boot@aribaud.net>
15 *
16 * Change to support call back into iMX28 bootrom
17 * Copyright (c) 2011 Marek Vasut <marek.vasut@gmail.com>
18 * on behalf of DENX Software Engineering GmbH
Marek Vasut926227e2011-11-08 23:18:21 +000019 */
20
21#include <asm-offsets.h>
22#include <config.h>
23#include <common.h>
Tom Rini4ddbade2022-05-25 12:16:03 -040024#include <system-constants.h>
Marek Vasut926227e2011-11-08 23:18:21 +000025
Marek Vasut926227e2011-11-08 23:18:21 +000026/*
27 *************************************************************************
28 *
Marek Vasut926227e2011-11-08 23:18:21 +000029 * Startup Code (reset vector)
30 *
31 * do important init only if we don't start from memory!
32 * setup Memory and board specific bits prior to relocation.
33 * relocate armboot to ram
34 * setup stack
35 *
36 *************************************************************************
37 */
38
Albert ARIBAUD9852cc62014-04-15 16:13:51 +020039 .globl reset
40reset:
Marek Vasut926227e2011-11-08 23:18:21 +000041 /*
Marek Vasutedc43b02013-09-20 01:36:44 +020042 * If the CPU is configured in "Wait JTAG connection mode", the stack
43 * pointer is not configured and is zero. This will cause crash when
44 * trying to push data onto stack right below here. Load the SP and make
45 * it point to the end of OCRAM if the SP is zero.
46 */
47 cmp sp, #0x00000000
Tom Rini4ddbade2022-05-25 12:16:03 -040048 ldreq sp, =SYS_INIT_SP_ADDR
Marek Vasutedc43b02013-09-20 01:36:44 +020049
50 /*
Marek Vasut926227e2011-11-08 23:18:21 +000051 * Store all registers on old stack pointer, this will allow us later to
52 * return to the BootROM and let the BootROM load U-Boot into RAM.
Marek Vasut0dc62ba2013-08-31 15:53:44 +020053 *
54 * WARNING: Register r0 and r1 are used by the BootROM to pass data
55 * to the called code. Register r0 will contain arbitrary
56 * data that are set in the BootStream. In case this code
57 * was started with CALL instruction, register r1 will contain
58 * pointer to the return value this function can then set.
59 * The code below MUST NOT CHANGE register r0 and r1 !
Marek Vasut926227e2011-11-08 23:18:21 +000060 */
61 push {r0-r12,r14}
62
Marek Vasut0dc62ba2013-08-31 15:53:44 +020063 /* Save control register c1 */
64 mrc p15, 0, r2, c1, c0, 0
65 push {r2}
Matthias Fuchsdcb3a8a2012-02-06 23:32:42 +000066
Marek Vasut0dc62ba2013-08-31 15:53:44 +020067 /* Set the cpu to SVC32 mode and store old CPSR register content. */
68 mrs r2, cpsr
69 push {r2}
70 bic r2, r2, #0x1f
71 orr r2, r2, #0xd3
72 msr cpsr, r2
Marek Vasut926227e2011-11-08 23:18:21 +000073
Marek Vasut926227e2011-11-08 23:18:21 +000074 bl board_init_ll
75
Marek Vasut0dc62ba2013-08-31 15:53:44 +020076 /* Restore BootROM's CPU mode (especially FIQ). */
77 pop {r2}
78 msr cpsr,r2
79
Matthias Fuchsdcb3a8a2012-02-06 23:32:42 +000080 /*
Marek Vasut0dc62ba2013-08-31 15:53:44 +020081 * Restore c1 register. Especially set exception vector location
82 * back to BootROM space which is required by bootrom for USB boot.
Matthias Fuchsdcb3a8a2012-02-06 23:32:42 +000083 */
Marek Vasut0dc62ba2013-08-31 15:53:44 +020084 pop {r2}
85 mcr p15, 0, r2, c1, c0, 0
86
87 pop {r0-r12,r14}
Matthias Fuchsdcb3a8a2012-02-06 23:32:42 +000088
89 /*
Marek Vasut0dc62ba2013-08-31 15:53:44 +020090 * In case this code was started by the CALL instruction, the register
91 * r0 is examined by the BootROM after this code returns. The value in
92 * r0 must be set to 0 to indicate successful return.
Matthias Fuchsdcb3a8a2012-02-06 23:32:42 +000093 */
Marek Vasut0dc62ba2013-08-31 15:53:44 +020094 mov r0, #0
Matthias Fuchsdcb3a8a2012-02-06 23:32:42 +000095
Marek Vasut926227e2011-11-08 23:18:21 +000096 bx lr