xref: /openbmc/u-boot/arch/arc/lib/start.S (revision 2bae75a4)
1/*
2 * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
3 *
4 * SPDX-License-Identifier:	GPL-2.0+
5 */
6
7#include <asm-offsets.h>
8#include <config.h>
9#include <linux/linkage.h>
10#include <asm/arcregs.h>
11
12ENTRY(_start)
13	/* Setup interrupt vector base that matches "__text_start" */
14	sr	__ivt_start, [ARC_AUX_INTR_VEC_BASE]
15
16	/* Setup stack- and frame-pointers */
17	mov	%sp, CONFIG_SYS_INIT_SP_ADDR
18	mov	%fp, %sp
19
20	/* Unconditionally disable caches */
21#ifdef CONFIG_ISA_ARCV2
22	bl	slc_flush
23	bl	slc_disable
24#endif
25	bl	flush_dcache_all
26	bl	dcache_disable
27	bl	icache_disable
28
29	/* Allocate and zero GD, update SP */
30	mov	%r0, %sp
31	bl	board_init_f_mem
32
33	/* Update stack- and frame-pointers */
34	mov	%sp, %r0
35	mov	%fp, %sp
36
37	/* Zero the one and only argument of "board_init_f" */
38	mov_s	%r0, 0
39	j	board_init_f
40ENDPROC(_start)
41
42/*
43 * void board_init_f_r_trampoline(stack-pointer address)
44 *
45 * This "function" does not return, instead it continues in RAM
46 * after relocating the monitor code.
47 *
48 * r0 = new stack-pointer
49 */
50ENTRY(board_init_f_r_trampoline)
51	/* Set up the stack- and frame-pointers */
52	mov	%sp, %r0
53	mov	%fp, %sp
54
55	/* Update position of intterupt vector table */
56	lr	%r0, [ARC_AUX_INTR_VEC_BASE]
57	ld	%r1, [%r25, GD_RELOC_OFF]
58	add	%r0, %r0, %r1
59	sr	%r0, [ARC_AUX_INTR_VEC_BASE]
60
61	/* Re-enter U-Boot by calling board_init_f_r */
62	j	board_init_f_r
63ENDPROC(board_init_f_r_trampoline)
64