u-boot/arch/arc/lib/start.S

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/*
* Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <asm-offsets.h>
#include <config.h>
#include <linux/linkage.h>
#include <asm/arcregs.h>
ENTRY(_start)
/* Setup interrupt vector base that matches "__text_start" */
sr __ivt_start, [ARC_AUX_INTR_VEC_BASE]
; Disable/enable I-cache according to configuration
lr r5, [ARC_BCR_IC_BUILD]
breq r5, 0, 1f ; I$ doesn't exist
lr r5, [ARC_AUX_IC_CTRL]
#ifndef CONFIG_SYS_ICACHE_OFF
bclr r5, r5, 0 ; 0 - Enable, 1 is Disable
#else
bset r5, r5, 0 ; I$ exists, but is not used
#endif
sr r5, [ARC_AUX_IC_CTRL]
1:
; Disable/enable D-cache according to configuration
lr r5, [ARC_BCR_DC_BUILD]
breq r5, 0, 1f ; D$ doesn't exist
lr r5, [ARC_AUX_DC_CTRL]
bclr r5, r5, 6 ; Invalidate (discard w/o wback)
#ifndef CONFIG_SYS_DCACHE_OFF
bclr r5, r5, 0 ; Enable (+Inv)
#else
bset r5, r5, 0 ; Disable (+Inv)
#endif
sr r5, [ARC_AUX_DC_CTRL]
1:
#ifdef CONFIG_ISA_ARCV2
; Disable System-Level Cache (SLC)
lr r5, [ARC_BCR_SLC]
breq r5, 0, 1f ; SLC doesn't exist
lr r5, [ARC_AUX_SLC_CTRL]
bclr r5, r5, 6 ; Invalidate (discard w/o wback)
bclr r5, r5, 0 ; Enable (+Inv)
sr r5, [ARC_AUX_SLC_CTRL]
1:
#endif
/* Establish C runtime stack and frame */
mov %sp, CONFIG_SYS_INIT_SP_ADDR
mov %fp, %sp
/* Allocate reserved area from current top of stack */
mov %r0, %sp
bl board_init_f_alloc_reserve
/* Set stack below reserved area, adjust frame pointer accordingly */
mov %sp, %r0
mov %fp, %sp
/* Initialize reserved area - note: r0 already contains address */
bl board_init_f_init_reserve
/* Zero the one and only argument of "board_init_f" */
mov_s %r0, 0
j board_init_f
ENDPROC(_start)
/*
* void board_init_f_r_trampoline(stack-pointer address)
*
* This "function" does not return, instead it continues in RAM
* after relocating the monitor code.
*
* r0 = new stack-pointer
*/
ENTRY(board_init_f_r_trampoline)
/* Set up the stack- and frame-pointers */
mov %sp, %r0
mov %fp, %sp
/* Update position of intterupt vector table */
lr %r0, [ARC_AUX_INTR_VEC_BASE]
ld %r1, [%r25, GD_RELOC_OFF]
add %r0, %r0, %r1
sr %r0, [ARC_AUX_INTR_VEC_BASE]
/* Re-enter U-Boot by calling board_init_f_r */
j board_init_f_r
ENDPROC(board_init_f_r_trampoline)