lowlevel_init.s

嵌入式试验箱S3C2410的bootloader源代码

/*
 * Board specific setup info
 *
 * (C) Copyright 2003
 * Texas Instruments, <www.ti.com>
 * Kshitij Gupta <[e-mail]>
 *
 * Modified for OMAP 1610 H2 board by Nishant Kamat, Jan 2004
 *
 * Modified for OMAP 5912 OSK board by Rishi Bhattacharya, Apr 2004
 * 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
 */

#include <config.h>
#include <version.h>

#if defined(CONFIG_OMAP1610)
#include <./configs/omap1510.h>
#endif


_TEXT_BASE:
	.word	TEXT_BASE	/* sdram load addr from config.mk */

.globl lowlevel_init
lowlevel_init:

	/*------------------------------------------------------*
	 * Ensure i-cache is enabled                            *
	 * To configure TC regs without fetching instruction    *
	 *------------------------------------------------------*/
	mrc	p15, 0, r0, c1, c0
	orr	r0, r0, #0x1000
	mcr	p15, 0, r0, c1, c0

	/*------------------------------------------------------*
	 *mask all IRQs by setting all bits in the INTMR default*
	 *------------------------------------------------------*/
	mov	r1, #0xffffffff
	ldr	r0, =REG_IHL1_MIR
	str	r1, [r0]
	ldr	r0, =REG_IHL2_MIR
	str	r1, [r0]

	/*------------------------------------------------------*
	 * Set up ARM CLM registers (IDLECT1)                   *
	 *------------------------------------------------------*/
	ldr	r0,	REG_ARM_IDLECT1
	ldr	r1,	VAL_ARM_IDLECT1
	str	r1,	[r0]

	/*------------------------------------------------------*
	 * Set up ARM CLM registers (IDLECT2)                   *
	 *------------------------------------------------------*/
	ldr	r0,	REG_ARM_IDLECT2
	ldr	r1,	VAL_ARM_IDLECT2
	str	r1,	[r0]

	/*------------------------------------------------------*
	 * Set up ARM CLM registers (IDLECT3)                   *
	 *------------------------------------------------------*/
	ldr	r0,	REG_ARM_IDLECT3
	ldr	r1,	VAL_ARM_IDLECT3
	str	r1,	[r0]

	mov	r1,	#0x01               /* PER_EN bit */
	ldr	r0,	REG_ARM_RSTCT2
	strh	r1,	[r0]            /* CLKM; Peripheral reset. */

	/* Set CLKM to Sync-Scalable */
	mov	r1,	#0x1000
	ldr	r0,	REG_ARM_SYSST

	mov	r2,	#0
1:	cmp	r2,	#1
	streqh	r1,	[r0]
	add	r2,	r2,	#1
	cmp	r2,	#0x100              /* wait for any bubbles to finish */
	bne	1b

	ldr	r1,	VAL_ARM_CKCTL
	ldr	r0,	REG_ARM_CKCTL
	strh	r1,	[r0]

	/* a few nops to let settle */
	nop
	nop
	nop
	nop
	nop
	nop
	nop
	nop
	nop
	nop

	/* setup DPLL 1 */
	/* Ramp up the clock to 96Mhz */
	ldr	r1,	VAL_DPLL1_CTL
	ldr	r0,	REG_DPLL1_CTL
	strh	r1,	[r0]
	ands	r1,	r1,	#0x10       /* Check if PLL is enabled. */
	beq	lock_end                /* Do not look for lock if BYPASS selected */
2:
	ldrh	r1,	[r0]
	ands	r1,	r1,	#0x01       /* Check the LOCK bit.*/
	beq 2b                      /* loop until bit goes hi. */
lock_end:

	/*------------------------------------------------------*
	 * Turn off the watchdog during init...                 *
 	 *------------------------------------------------------*/
	ldr	r0,	REG_WATCHDOG
	ldr	r1,	WATCHDOG_VAL1
	str	r1,	[r0]
	ldr	r1,	WATCHDOG_VAL2
	str	r1,	[r0]
	ldr	r0,	REG_WSPRDOG
	ldr	r1,	WSPRDOG_VAL1
	str	r1,	[r0]
	ldr	r0,	REG_WWPSDOG

watch1Wait:
	ldr	r1,	[r0]
	tst	r1,	#0x10
	bne	watch1Wait

	ldr	r0,	REG_WSPRDOG
	ldr	r1,	WSPRDOG_VAL2
	str	r1,	[r0]
	ldr	r0,	REG_WWPSDOG
watch2Wait:
	ldr	r1,	[r0]
	tst	r1,	#0x10
	bne	watch2Wait

	/* Set memory timings corresponding to the new clock speed */
	ldr	r3, VAL_SDRAM_CONFIG_SDF0

	/* Check execution location to determine current execution location
	 * and branch to appropriate initialization code.
	 */
	mov	r0,	#0x10000000         /* Load physical SDRAM base. */
	mov	r1,	pc                  /* Get current execution location. */
	cmp	r1,	r0                  /* Compare. */
	bge	skip_sdram              /* Skip over EMIF-fast initialization if running from SDRAM. */

	/* identify the device revision, -- TMX or TMP(TMS) */
	ldr	r0, REG_DEVICE_ID
	ldr	r1, [r0]

	ldr	r0, VAL_DEVICE_ID_TMP
	mov	r1, r1, lsl #15
	mov	r1, r1, lsr #16
	cmp	r0, r1
	bne	skip_TMP_Patch

	/* Enable TMP/TMS device new features */
	mov	r0, #1
	ldr	r1, REG_TC_EMIFF_DOUBLER
	str	r0, [r1]

	/* Enable new ac parameters */
	mov	r0, #0x0b
	ldr	r1, REG_SDRAM_CONFIG2
	str	r0, [r1]

	ldr	r3, VAL_SDRAM_CONFIG_SDF1

skip_TMP_Patch:

	/*
	* Delay for SDRAM initialization.
	*/
	mov	r0,	#0x1800		/* value should be checked */
3:
	subs	r0,	r0,	#0x1	/* Decrement count */
	bne 	3b

	/*
	 * Set SDRAM control values. Disable refresh before MRS command.
	 */

	/* mobile ddr operation */
	ldr	r0,	REG_SDRAM_OPERATION
	mov	r2,	#07
	str	r2,	[r0]

	/* config register */
	ldr	r0,	REG_SDRAM_CONFIG
	str	r3,	[r0]

	/* manual command register */
	ldr	r0,	REG_SDRAM_MANUAL_CMD

	/* issue set cke high */
	mov	r1,	#CMD_SDRAM_CKE_SET_HIGH
	str	r1,	[r0]

	/* issue nop */
	mov	r1,	#CMD_SDRAM_NOP
	str	r1,	[r0]

	mov	r2,	#0x0100
waitMDDR1:
	subs	r2,	r2,	 #1
	bne	waitMDDR1	/* delay loop */

	/* issue precharge */
	mov	r1,	#CMD_SDRAM_PRECHARGE
	str	r1,	[r0]

	/* issue autorefresh x 2 */
	mov	r1,	#CMD_SDRAM_AUTOREFRESH
	str	r1,	[r0]
	str	r1,	[r0]

	/* mrs register ddr mobile */
	ldr	r0,	REG_SDRAM_MRS
	mov	r1,	#0x33
	str	r1,	[r0]

	/* emrs1 low-power register */
	ldr	r0,	REG_SDRAM_EMRS1
	/* self refresh on all banks */
	mov	r1,	#0
	str	r1,	[r0]

	ldr	r0,	REG_DLL_URD_CONTROL
	ldr	r1,	DLL_URD_CONTROL_VAL
	str	r1,	[r0]

	ldr	r0,	REG_DLL_LRD_CONTROL
	ldr	r1,	DLL_LRD_CONTROL_VAL
	str	r1,	[r0]

	ldr	r0,	REG_DLL_WRT_CONTROL
	ldr	r1,	DLL_WRT_CONTROL_VAL
	str	r1,	[r0]

	/* delay loop */
	mov	r0,	#0x0100
waitMDDR2:
	subs	r0,	r0,	#1
	bne	waitMDDR2

	/*
	 * Delay for SDRAM initialization.
	 */
	mov	r0,	#0x1800
4:
	subs	r0,	r0,	#1	/* Decrement count. */
	bne	4b
	b	common_tc

skip_sdram:
	ldr	r0,	REG_SDRAM_CONFIG
	str	r3,	[r0]

common_tc:
	/* slow interface */
	ldr	r1,	VAL_TC_EMIFS_CS0_CONFIG
	ldr	r0,	REG_TC_EMIFS_CS0_CONFIG
	str	r1,	[r0] /* Chip Select 0 */

	ldr	r1,	VAL_TC_EMIFS_CS1_CONFIG
	ldr	r0,	REG_TC_EMIFS_CS1_CONFIG
	str	r1,	[r0] /* Chip Select 1 */

	ldr	r1,	VAL_TC_EMIFS_CS3_CONFIG
	ldr	r0,	REG_TC_EMIFS_CS3_CONFIG
	str	r1,	[r0] /* Chip Select 3 */

	ldr	r1,	VAL_TC_EMIFS_DWS
	ldr	r0,	REG_TC_EMIFS_DWS
	str	r1,	[r0] /* Enable EMIFS.RDY for CS1 (ether) */

#ifdef CONFIG_H2_OMAP1610
	/* inserting additional 2 clock cycle hold time for LAN */
	ldr     r0,     REG_TC_EMIFS_CS1_ADVANCED
	ldr    	r1,     VAL_TC_EMIFS_CS1_ADVANCED
	str     r1,     [r0]
#endif
	/* Start MPU Timer 1 */
	ldr	r0,	REG_MPU_LOAD_TIMER
	ldr	r1,	VAL_MPU_LOAD_TIMER
	str	r1,	[r0]

	ldr	r0,	REG_MPU_CNTL_TIMER
	ldr	r1,	VAL_MPU_CNTL_TIMER
	str	r1,	[r0]

	/* back to arch calling code */
	mov	pc,	lr

	/* the literal pools origin */
	.ltorg

REG_DEVICE_ID:			/* 32 bits */
	.word 0xfffe2004
REG_TC_EMIFS_CONFIG:
	.word 0xfffecc0c
REG_TC_EMIFS_CS0_CONFIG:	/* 32 bits */
	.word 0xfffecc10
REG_TC_EMIFS_CS1_CONFIG:	/* 32 bits */
	.word 0xfffecc14
REG_TC_EMIFS_CS2_CONFIG:	/* 32 bits */
	.word 0xfffecc18
REG_TC_EMIFS_CS3_CONFIG:	/* 32 bits */
	.word 0xfffecc1c
REG_TC_EMIFS_DWS:		/* 32 bits */
	.word 0xfffecc40
#ifdef CONFIG_H2_OMAP1610
REG_TC_EMIFS_CS1_ADVANCED:	/* 32 bits */
	.word 0xfffecc54
#endif

/* MPU clock/reset/power mode control registers */
REG_ARM_CKCTL:			/* 16 bits */
	.word 0xfffece00
REG_ARM_IDLECT3:		/* 16 bits */
	.word 0xfffece24
REG_ARM_IDLECT2:		/* 16 bits */
	.word 0xfffece08
REG_ARM_IDLECT1:		/* 16 bits */
	.word 0xfffece04
REG_ARM_RSTCT2:			/* 16 bits */
	.word 0xfffece14
REG_ARM_SYSST:			/* 16 bits */
	.word 0xfffece18

/* DPLL control registers */
REG_DPLL1_CTL:			/* 16 bits */
	.word 0xfffecf00

/* Watch Dog register */
/* secure watchdog stop */
REG_WSPRDOG:
	.word 0xfffeb048
/* watchdog write pending */
REG_WWPSDOG:
	.word 0xfffeb034

WSPRDOG_VAL1:
	.word 0x0000aaaa
WSPRDOG_VAL2:
	.word 0x00005555

/* SDRAM config is: auto refresh enabled, 16 bit 4 bank,
 counter @8192 rows, 10 ns, 8 burst */
REG_SDRAM_CONFIG:
	.word 0xfffecc20
REG_SDRAM_CONFIG2:
	.word 0xfffecc3c
REG_TC_EMIFF_DOUBLER:		/* 32 bits */
	.word 0xfffecc60

/* Operation register */
REG_SDRAM_OPERATION:
	.word 0xfffecc80

/* Manual command register */
REG_SDRAM_MANUAL_CMD:
	.word 0xfffecc84

/* SDRAM MRS (New) config is: CAS latency is 2, burst length 8 */
REG_SDRAM_MRS:
	.word 0xfffecc70

/* SDRAM MRS (New) config is: CAS latency is 2, burst length 8 */
REG_SDRAM_EMRS1:
	.word 0xfffecc78

/* WRT DLL register */
REG_DLL_WRT_CONTROL:
	.word 0xfffecc68
DLL_WRT_CONTROL_VAL:
	.word 0x03f00002    /* Phase of 72deg, write offset +31  */

/* URD DLL register */
REG_DLL_URD_CONTROL:
	.word 0xfffeccc0
DLL_URD_CONTROL_VAL:
	.word 0x00800002    /* Phase of 72deg, read offset +31  */

/* LRD DLL register */
REG_DLL_LRD_CONTROL:
	.word 0xfffecccc
DLL_LRD_CONTROL_VAL:
	.word 0x00800002    /* read offset +31  */

REG_WATCHDOG:
	.word 0xfffec808
WATCHDOG_VAL1:
	.word 0x000000f5
WATCHDOG_VAL2:
	.word 0x000000a0

REG_MPU_LOAD_TIMER:
	.word 0xfffec504
REG_MPU_CNTL_TIMER:
	.word 0xfffec500
VAL_MPU_LOAD_TIMER:
	.word 0xffffffff
VAL_MPU_CNTL_TIMER:
	.word 0xffffffa1

/* 96 MHz Samsung Mobile DDR */
/* Original setting for TMX device */
VAL_SDRAM_CONFIG_SDF0:
    .word 0x0014e6fe

/* NEW_SYS_FREQ mode (valid only TMP/TMS devices) */
VAL_SDRAM_CONFIG_SDF1:
    .word 0x0114e6fe

VAL_ARM_CKCTL:
	.word 0x2000		/* was:	0x3000, now use CLK_REF for timer input */
VAL_DPLL1_CTL:
	.word 0x2830

#ifdef CONFIG_OSK_OMAP5912
VAL_TC_EMIFS_CS0_CONFIG:
	.word 0x002130b0
VAL_TC_EMIFS_CS1_CONFIG:
	.word 0x00001133
VAL_TC_EMIFS_CS2_CONFIG:
	.word 0x000055f0
VAL_TC_EMIFS_CS3_CONFIG:
	.word 0x88013141
VAL_TC_EMIFS_DWS:	/* Enable EMIFS.RDY for CS1 access (ether) */
	.word 0x000000c0
VAL_DEVICE_ID_TMP:	/* TMP/TMS=0xb65f, TMX=0xb58c */
	.word 0xb65f
#endif

#ifdef CONFIG_H2_OMAP1610
VAL_TC_EMIFS_CS0_CONFIG:
	.word 0x00203331
VAL_TC_EMIFS_CS1_CONFIG:
	.word 0x8180fff3
VAL_TC_EMIFS_CS2_CONFIG:
	.word 0xf800f22a
VAL_TC_EMIFS_CS3_CONFIG:
	.word 0x88013141
VAL_TC_EMIFS_CS1_ADVANCED:
	.word 0x00000022
#endif

VAL_ARM_IDLECT1:
	.word 0x00000400
VAL_ARM_IDLECT2:
	.word 0x00000886
VAL_ARM_IDLECT3:
	.word 0x00000015

/* command values */
.equ CMD_SDRAM_NOP,             0x00000000
.equ CMD_SDRAM_PRECHARGE,       0x00000001
.equ CMD_SDRAM_AUTOREFRESH,     0x00000002
.equ CMD_SDRAM_CKE_SET_HIGH,    0x00000007