board/ruby/start.S

/*
 * (C) Copyright 2010 Quantenna Communications Inc.
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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; either version 2 of
 * the License, or (at your option) any later version.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

/*****************************************************************************
 * This module provides several critical functions for a couple of scenarios:
 *	1) For the case of uboot in flash, copy code to target
 *	2) For the case of uboot loaded via serial, make clean copy for subsequent flash ops
 *	3) Initialize ddr
 *	4) Clear BSS
 *****************************************************************************/

#include <config.h>
#include <asm/arcregs.h>
#include <asm/arch/platform.h>
#include <ruby_version.h>
#include <topaz_config.h>
#include <uboot_header.h>
#include "timestamp_autogenerated.h"

/*****MACROS**********************************************************************************/

#include "start.inl"

/*****TEXT SECTION****************************************************************************/

	.section .text
	.align 4
_start:
.globl _start
	/*
	 * DON'T put any code before .ascii "U-BOOT ...",
	 * bootcfg driver will check "U-BOOT" string.
	 */
#if defined(PIGGY_BUILD) || !defined(RUBY_MINI)
	b	cold_boot
#else
	b	run_c
#endif
	/* need easily identifiable tag at beginning of file with version */
	.ascii "U-BOOT " RUBY_UBOOT_VERSION "\0"

	.align	32
early_flash_config_start:
	.globl early_flash_config_start
	/* Early board config metadata can go here */
	/* Space reserved for first three fields of early_flash_config structure */
#ifdef RUBY_BOOT_METHOD
	.word RUBY_BOOT_METHOD
#else
	.word RUBY_BOOT_METHOD_TRYLOOP
#endif
	.skip	8
	/* This is required for backward compatibility when U-Boot Mini
	 * runs U-Boot code with offset 0x30 */
	.align 16
	b	warm_boot

	.ascii U_BOOT_TIME_UTC "\0"
#ifdef U_BOOT_TINY
	.ascii U_BOOT_TYPE_TINY
#elif defined(U_BOOT_MINI)
	.ascii U_BOOT_TYPE_MINI
#else
	.ascii U_BOOT_TYPE_LARGE
#endif
	.align 32

early_flash_config_end:
	.globl early_flash_config_end

warm_boot:
	.globl warm_boot
	mov	r0, warm_boot
	sub	r0, r0, _start
	b       1f
cold_boot:
#if defined(PIGGY_BUILD) 
	/* Init CPU timer to get the boot up time */
	mov_s	r0, 0xFFFFFFFF
	sr	r0, [ARC_REG_TIMER1_LIMIT]
	mov_s	r0, 0
	sr	r0, [ARC_REG_TIMER1_CNT]
	mov_s	r0, TIMER_CTRL_NH
	sr	r0, [ARC_REG_TIMER1_CTRL]
#endif
	mov_s	r0, 0
1:
	/* SCRATCH_DATA0 is stored with the offset of warm boot */
	sr	r0, [SCRATCH_DATA0]

#if defined(PIGGY_BUILD) || !defined(RUBY_MINI)
; By default, disable i-cache/d-cache in bootloader start file
; and re-enable in board specific settings in U-boot
disable_dcache:
	lr	r0, [0x48]	; dc_ctrl register
	or	r0, r0, 0x1
	sr	r0, [0x48]

#ifdef TOPAZ_ICACHE_WORKAROUND
disable_icache:
	; Disable i-cache
	lr	r0, [0x11]	; ic_ctrl register
	or	r0, r0, 0x1
	sr	r0, [0x11]
#endif

#if defined(PIGGY_BUILD)
        /* reset bus monitors */
        mov     r0, 0
        mov     r1, 0xe0000200
        st.di.as r0,[r1, 0x00]
        st.di.as r0,[r1, 0x10]
        st.di.as r0,[r1, 0x20]
        st.di.as r0,[r1, 0x30]
        st.di.as r0,[r1, 0x40]
        st.di.as r0,[r1, 0x50]
        st.di.as r0,[r1, 0x60]
        st.di.as r0,[r1, 0x70]
        ld.di.as r0,[r1, 0x00]
        ld.di.as r0,[r1, 0x10]
        ld.di.as r0,[r1, 0x20]
        ld.di.as r0,[r1, 0x30]
        ld.di.as r0,[r1, 0x40]
        ld.di.as r0,[r1, 0x50]
        ld.di.as r0,[r1, 0x60]
        ld.di.as r0,[r1, 0x70]
#endif

	M_REMOVE_FROM_RESET
	M_GOTO_IF_EXEC_REMAPPED_SRAM run_c
#ifdef FLIPBIT
	M_IF_BOOT_FROM_FLASH
	bne	ruby_flip_mmap /* if we are running not from flash call the flip routine to
				* flip the bit in place; will return to ruby_boot label */
#endif
	j	ruby_boot - TEXT_BASE + RUBY_SPI_FLASH_ADDR /* jump to physical spi address */

ruby_boot:
	.globl ruby_boot
	M_IF_BOOT_FROM_FLASH
	bne	run_c
#ifdef FLIPBIT
	M_REMAP_MEM
#endif
	M_COPY_UBOOT TEXT_BASE, RUBY_SPI_FLASH_ADDR
	j	run_c
#endif /* defined(PIGGY_BUILD) || !defined(RUBY_MINI) */

run_c:
	M_FILL_BSS
#if defined(CONFIG_ARC_MAKE_UBOOT_COPY) && \
		(defined(PIGGY_BUILD) || !defined(RUBY_MINI))
	M_COPY_UBOOT CONFIG_ARC_FREE_BEGIN, TEXT_BASE
#endif
	M_GOTO_C_CODE

/*********************************************************************************************/