xref: /openbmc/u-boot/arch/arc/lib/start.S (revision 2a0b7dc3)
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	; Disable/enable I-cache according to configuration
17	lr	r5, [ARC_BCR_IC_BUILD]
18	breq	r5, 0, 1f		; I$ doesn't exist
19	lr	r5, [ARC_AUX_IC_CTRL]
20#ifndef CONFIG_SYS_ICACHE_OFF
21	bclr	r5, r5, 0		; 0 - Enable, 1 is Disable
22#else
23	bset	r5, r5, 0		; I$ exists, but is not used
24#endif
25	sr	r5, [ARC_AUX_IC_CTRL]
26
271:
28	; Disable/enable D-cache according to configuration
29	lr	r5, [ARC_BCR_DC_BUILD]
30	breq	r5, 0, 1f		; D$ doesn't exist
31	lr	r5, [ARC_AUX_DC_CTRL]
32	bclr	r5, r5, 6		; Invalidate (discard w/o wback)
33#ifndef CONFIG_SYS_DCACHE_OFF
34	bclr	r5, r5, 0		; Enable (+Inv)
35#else
36	bset	r5, r5, 0		; Disable (+Inv)
37#endif
38	sr	r5, [ARC_AUX_DC_CTRL]
39
401:
41#ifdef CONFIG_ISA_ARCV2
42	; Disable System-Level Cache (SLC)
43	lr	r5, [ARC_BCR_SLC]
44	breq	r5, 0, 1f		; SLC doesn't exist
45	lr	r5, [ARC_AUX_SLC_CTRL]
46	bclr	r5, r5, 6		; Invalidate (discard w/o wback)
47	bclr	r5, r5, 0		; Enable (+Inv)
48	sr	r5, [ARC_AUX_SLC_CTRL]
49
501:
51#endif
52
53	/* Setup stack- and frame-pointers */
54	mov	%sp, CONFIG_SYS_INIT_SP_ADDR
55	mov	%fp, %sp
56
57	/* Allocate and zero GD, update SP */
58	mov	%r0, %sp
59	bl	board_init_f_mem
60
61	/* Update stack- and frame-pointers */
62	mov	%sp, %r0
63	mov	%fp, %sp
64
65	/* Zero the one and only argument of "board_init_f" */
66	mov_s	%r0, 0
67	j	board_init_f
68ENDPROC(_start)
69
70/*
71 * void board_init_f_r_trampoline(stack-pointer address)
72 *
73 * This "function" does not return, instead it continues in RAM
74 * after relocating the monitor code.
75 *
76 * r0 = new stack-pointer
77 */
78ENTRY(board_init_f_r_trampoline)
79	/* Set up the stack- and frame-pointers */
80	mov	%sp, %r0
81	mov	%fp, %sp
82
83	/* Update position of intterupt vector table */
84	lr	%r0, [ARC_AUX_INTR_VEC_BASE]
85	ld	%r1, [%r25, GD_RELOC_OFF]
86	add	%r0, %r0, %r1
87	sr	%r0, [ARC_AUX_INTR_VEC_BASE]
88
89	/* Re-enter U-Boot by calling board_init_f_r */
90	j	board_init_f_r
91ENDPROC(board_init_f_r_trampoline)
92