src/soc/marvell/armada38x/bootblock_asm.S

/*
 * This file is part of the coreboot project.
 *
 * Copyright 2015 Google Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <arch/asm.h>

.arm
	/*
	 * Just in case the maskrom or the vendor basic firmware passes on a
	 * parameter when calling the bootblock, store it here for handling by C
	 * code.
	 */
	.section .bss, "aw" @nobits
	.global maskrom_param
	.align 4
maskrom_param:
	.word 0

ENTRY(_start)
	/*
	 * Set the cpu to System mode with IRQ and FIQ disabled. Prefetch/Data
	 * aborts may happen early and crash before the abort handlers are
	 * installed, but at least the problem will show up near the code that
	 * causes it.
	 */
	msr	cpsr_cxf, #0xdf
	bl	_thumb_start
ENDPROC(_start)

.thumb
ENTRY(_thumb_start)

	/* Preserve the maskrom passed value, if any */
	mov	r10, r0

	/* Disable L2 Cache */
        ldr r1, =0x0
        ldr r0, =0xD0008100
        str r1, [r0]

        /* Disable windows that overlap with 0xF1000000 */
        /* By default, window #12 overlaps with 0xF1000000 */
        mov  r1, #0
        ldr  r0, =0xD00200B0
        str  r1, [r0]
        /* Set Registers Base address. */
        ldr  r1, =0xf1000000
        ldr  r0, =0xD0020080
        str  r1, [r0]
        /* Update SCU (peripheral) register Base address with
	 * correct INTER_REG_BASE
	 */
        ldr r2, = 0xC000                /* SCU offset = 0xC000 */
        add r1, r1, r2                  /* r1 = INTER_REG_BASE + SCU_OFFSET */
        mcr p15, 4, r1, c15, c0, 0      /* Write SCU base register */

	bl	arm_init_caches

	/*
	 * From Cortex-A Series Programmer's Guide:
	 * Only CPU 0 performs initialization. Other CPUs go into WFI
	 * to do this, first work out which CPU this is
	 * this code typically is run before any other initialization step
	 */
	mrc p15, 0, r1, c0, c0, 5	@ Read Multiprocessor Affinity Register
	and r1, r1, #0x3 @ Extract CPU ID bits
	cmp r1, #0
	bne wait_for_interrupt		@ If this is not core0, wait

	/*
	 * Initialize the stack to a known value. This is used to check for
	 * stack overflow later in the boot process.
	 */
	ldr	r0, =_stack
	ldr	r1, =_estack
	ldr	r2, =0xdeadbeef
init_stack_loop:
	str	r2, [r0]
	add	r0, #4
	cmp	r0, r1
	bne	init_stack_loop

        ldr     r0, =_bss
        ldr     r1, =_ebss
        mov     r2, #0x00000000         /* prepare zero to clear BSS */
clbss_l:
	str     r2, [r0]
	add     r0, #4
	cmp     r0, r1
	bne     clbss_l

call_bootblock:

	/* Restore parameter passed in by maskrom/vendor firmware. */
	ldr	r0, =maskrom_param
	str	r10, [r0]

	/* Set stackpointer in internal RAM to call bootblock main() */
	ldr	sp, =_estack
	ldr	r0,=0x00000000
	 /*
	  * The current design of cpu_info places the struct at the top of the
	  * stack. Free enough space to accommodate for that, but make sure it's
	  * 8-byte aligned for ABI compliance.
	  */
	sub	sp, sp, #16
	bl	main

wait_for_interrupt:
	wfi
	mov	pc, lr			@ back to my caller
ENDPROC(_thumb_start)