bcm91125cpci_init.s

一个很好的嵌入式linux平台下的bootloader

/*  *********************************************************************
    *  SB1250 Board Support Package
    *  
    *  Board-specific initialization		File: BCM91125CPCI_INIT.S
    *
    *  This module contains the assembly-language part of the init
    *  code for this board support package.  The routine
    *  "board_earlyinit" lives here.
    *  
    *  Author:  Mitch Lichtenberg
    *  
    *********************************************************************  
    *
    *  Copyright 2000,2001,2002,2003
    *  Broadcom Corporation. All rights reserved.
    *  
    *  This software is furnished under license and may be used and 
    *  copied only in accordance with the following terms and 
    *  conditions.  Subject to these conditions, you may download, 
    *  copy, install, use, modify and distribute modified or unmodified 
    *  copies of this software in source and/or binary form.  No title 
    *  or ownership is transferred hereby.
    *  
    *  1) Any source code used, modified or distributed must reproduce 
    *     and retain this copyright notice and list of conditions 
    *     as they appear in the source file.
    *  
    *  2) No right is granted to use any trade name, trademark, or 
    *     logo of Broadcom Corporation.  The "Broadcom Corporation" 
    *     name may not be used to endorse or promote products derived 
    *     from this software without the prior written permission of 
    *     Broadcom Corporation.
    *  
    *  3) THIS SOFTWARE IS PROVIDED "AS-IS" AND ANY EXPRESS OR
    *     IMPLIED WARRANTIES, INCLUDING BUT NOT LIMITED TO, ANY IMPLIED
    *     WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR 
    *     PURPOSE, OR NON-INFRINGEMENT ARE DISCLAIMED. IN NO EVENT 
    *     SHALL BROADCOM BE LIABLE FOR ANY DAMAGES WHATSOEVER, AND IN 
    *     PARTICULAR, BROADCOM SHALL NOT BE LIABLE FOR DIRECT, INDIRECT,
    *     INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 
    *     (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
    *     GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
    *     BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 
    *     OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR 
    *     TORT (INCLUDING NEGLIGENCE OR OTHERWISE), EVEN IF ADVISED OF 
    *     THE POSSIBILITY OF SUCH DAMAGE.
    ********************************************************************* */


#include "sbmips.h"
#include "sb1250_genbus.h"
#include "sb1250_regs.h"
#include "sb1250_scd.h"
#include "bsp_config.h"
#include "cpu_config.h"
#include "mipsmacros.h"
#include "sb1250_draminit.h"
#include "sb1250_smbus.h"

		.text

/*  *********************************************************************
    *  Macros
    ********************************************************************* */

/*
 * Define this to send the LED messages to the serial port instead
 * of to the LEDs.
 */

/*#define _SERIAL_PORT_LEDS_*/

#ifdef _SERIAL_PORT_LEDS_
#include "sb1250_uart.h"		/* need this for serial defs */
#endif


/*  *********************************************************************
    *  BOARD_EARLYINIT()
    *  
    *  Initialize board registers.  This is the earliest 
    *  time the BSP gets control.  This routine cannot assume that
    *  memory is operational, and therefore all code in this routine
    *  must run from registers only.  The $ra register must not
    *  be modified, as it contains the return address.
    *
    *  This routine will be called from uncached space, before
    *  the caches are initialized.  If you want to make
    *  subroutine calls from here, you must use the CALLKSEG1 macro.
    *
    *  Among other things, this is where the GPIO registers get 
    *  programmed to make on-board LEDs function, or other startup
    *  that has to be done before anything will work.
    *  
    *  Input parameters: 
    *  	   nothing
    *  	   
    *  Return value:
    *  	   nothing
    ********************************************************************* */

LEAF(board_earlyinit)

	#
	# Reprogram the SCD to make sure UART0 is enabled.
	# Some BCM91125CPCI boards have the SER0 enable bit when
	# they're not supposed to, which switches the UART
	# into synchronous mode.  Kill off the SCD bit.
	# XXX this should be investigated in hardware, as 
	# XXX it is a strap option on the CPU.
	#

		li      t0,PHYS_TO_K1(A_SCD_SYSTEM_CFG)
		ld	t1,0(t0)
		dli	t2,~(M_SYS_SER0_ENABLE|M_SYS_SER1_ENABLE|M_SYS_LDT_TEST_EN|M_SYS_GEN_PARITY_EN)
		and	t1,t1,t2
		dli	t2,M_SYS_PCMCIA_ENABLE
		or	t1,t1,t2
		sd	t1,0(t0)


       #
       # Configure the GPIOs
       #

		li	t0,PHYS_TO_K1(A_GPIO_DIRECTION)
		li	t1,GPIO_OUTPUT_MASK
		sd	t1,0(t0)

		li	t0,PHYS_TO_K1(A_GPIO_INT_TYPE)
		li	t1,GPIO_INTERRUPT_MASK
		sd	t1,0(t0)

       #
       # Turn off the diagnostic LED.
       #
		li	t0,PHYS_TO_K1(A_GPIO_PIN_CLR)
		li	t1,M_GPIO_DEBUG_LED
		sd	t1,0(t0)

       #
       # Configure the LEDs
       #     

		li	t0,PHYS_TO_K1(A_IO_EXT_CS_BASE(LEDS_CS))
		li	t1,LEDS_PHYS >> S_IO_ADDRBASE
		sd	t1,R_IO_EXT_START_ADDR(t0)

		li	t1,LEDS_SIZE-1	/* Needs to be 1 smaller, se UM for details */
		sd	t1,R_IO_EXT_MULT_SIZE(t0)

		li	t1,LEDS_TIMING0
		sd	t1,R_IO_EXT_TIME_CFG0(t0)

		li	t1,LEDS_TIMING1
		sd	t1,R_IO_EXT_TIME_CFG1(t0)

		li	t1,LEDS_CONFIG
		sd	t1,R_IO_EXT_CFG(t0)

	#
	# Configure CS 0 size from 4MB to 16MB.  Do the same for CS1
	#
		li	t0,PHYS_TO_K1(A_IO_EXT_CS_BASE(BOOTROM_CS))

		li	t1,BOOTROM_SIZE-1
		sd	t1,R_IO_EXT_MULT_SIZE(t0)


       #
       # Configure the alternate boot ROM
       #     

		li	t0,PHYS_TO_K1(A_IO_EXT_CS_BASE(ALT_BOOTROM_CS))

		li	t1,ALT_BOOTROM_PHYS >> S_IO_ADDRBASE
		sd	t1,R_IO_EXT_START_ADDR(t0)

		li	t1,BOOTROM_SIZE-1	/* use bigger size in case switch is set */
		sd	t1,R_IO_EXT_MULT_SIZE(t0)

		li	t1,ALT_BOOTROM_TIMING0
		sd	t1,R_IO_EXT_TIME_CFG0(t0)

		li	t1,ALT_BOOTROM_TIMING1
		sd	t1,R_IO_EXT_TIME_CFG1(t0)

		li	t1,ALT_BOOTROM_CONFIG
		sd	t1,R_IO_EXT_CFG(t0)

       #
       # Configure the PCMCIA
       #     

		li	t0,PHYS_TO_K1(A_IO_EXT_CS_BASE(PCMCIA_CS))

		li	t1,PCMCIA_PHYS >> S_IO_ADDRBASE
		sd	t1,R_IO_EXT_START_ADDR(t0)

		li	t1,PCMCIA_SIZE-1
		sd	t1,R_IO_EXT_MULT_SIZE(t0)

		li	t1,PCMCIA_TIMING0
		sd	t1,R_IO_EXT_TIME_CFG0(t0)

		li	t1,PCMCIA_TIMING1
		sd	t1,R_IO_EXT_TIME_CFG1(t0)

		li	t1,PCMCIA_CONFIG
		sd	t1,R_IO_EXT_CFG(t0)

#ifdef _SERIAL_PORT_LEDS_

	# Program the mode register for 8 bits/char, no parity

		li	t0,PHYS_TO_K1(A_DUART_MODE_REG_1_A)	
		li	t1,V_DUART_BITS_PER_CHAR_8 | V_DUART_PARITY_MODE_NONE
		sd	t1,(t0)

	# Program the mode register for 1 stop bit, ignore CTS

		li	t0,PHYS_TO_K1(A_DUART_MODE_REG_2_A)	
		li	t1,M_DUART_STOP_BIT_LEN_1
		sd	t1,(t0)

	# Program the baud rate to 115200

		li	t0,PHYS_TO_K1(A_DUART_CLK_SEL_A)
		li	t1,V_DUART_BAUD_RATE(CFG_SERIAL_BAUD_RATE)
		sd	t1,(t0)

	# Dont use any interrupts

		li	t0,PHYS_TO_K1(A_DUART_IMR)
		ld	t1,(t0)
		and	t1,~M_DUART_IMR_ALL_A
		sd	t1,(t0)

	# Enable sending and receiving

		li	t0,PHYS_TO_K1(A_DUART_CMD_A)
		li	t1,M_DUART_RX_EN | M_DUART_TX_EN
		sd	t1,(t0)

#endif

	j	ra

END(board_earlyinit)


/*  *********************************************************************
    *  BOARD_DRAMINFO
    *  
    *  Return the address of the DRAM information table
    *  
    *  Input parameters: 
    *  	   nothing
    *  	   
    *  Return value:
    *  	   v0 - DRAM info table, return 0 to use default table
    ********************************************************************* */


LEAF(board_draminfo)

	la	v0,spd
	j	ra

spd:

	/*
	 * Globals: Only one memory controller, no port interleaving
	 */
	DRAM_GLOBALS(0)
        DRAM_CHAN_CFG(MC_CHAN1, DRT10(8,0), JEDEC, CASCHECK, BLKSIZE32, CFG_DRAM_CSINTERLEAVE, CFG_DRAM_ECC, 0)

	/* XXX Reduce drive strength a little.  Might not be necessary. */
	DRAM_CHAN_CLKCFG(0x00,0x08,0x08,0x00,0x0F,0x0F)

	DRAM_CS_SPD(MC_CS0, 0, SODIMM1_SMBUS_CHAN, SODIMM1_SMBUS_DEV)
	DRAM_EOT


END(board_draminfo)

/*  *********************************************************************
    *  BOARD_UARTA_TXCHAR
    *  
    *  Transmit a single character via UART A
    *  
    *  Input parameters: 
    *  	   a0 - character to transmit (low-order 8 bits)
    *  	   
    *  Return value:
    *  	   nothing
    *  	   
    *  Registers used:
    *  	   t0,t1
    ********************************************************************* */
#ifdef _SERIAL_PORT_LEDS_
LEAF(board_uarta_txchar)

	# Wait until there is space in the transmit buffer

1:		li	t0,PHYS_TO_K1(A_DUART_STATUS_A)
		ld	t1,(t0)			# Get status bits
		and	t1,M_DUART_TX_RDY	# test for ready
		beq	t1,0,1b			# keep going till ready

	# Okay, now send the character.

		li	t0,PHYS_TO_K1(A_DUART_TX_HOLD_A)
		sd	a0,(t0)

	# done!

		j	ra

END(board_uarta_txchar)
#endif

/*  *********************************************************************
    *  BOARD_SETLEDS(x)
    *  
    *  Set LEDs for boot-time progress indication.  Not used if
    *  the board does not have progress LEDs.  This routine
    *  must not call any other routines, since it may be invoked
    *  either from KSEG0 or KSEG1 and it may be invoked 
    *  whether or not the icache is operational.
    *  
    *  Input parameters: 
    *  	   a0 - LED value (8 bits per character, 4 characters)
    *  	   
    *  Return value:
    *  	   nothing
    *  
    *  Registers used:
    *  	   t0,t1,t2,t3
    ********************************************************************* */

#define LED_CHAR0	(8*3)
#define LED_CHAR1	(8*2)
#define LED_CHAR2	(8*1)
#define LED_CHAR3	(8*0)

LEAF(board_setleds)


	/*
	 * Sending to LEDs
	 */
		li	t0,PHYS_TO_K1(LEDS_PHYS)

		rol	a0,a0,8
		and	t1,a0,0xFF
		sb	t1,LED_CHAR0(t0)

		rol	a0,a0,8
		and	t1,a0,0xFF
		sb	t1,LED_CHAR1(t0)

		rol	a0,a0,8
		and	t1,a0,0xFF
		sb	t1,LED_CHAR2(t0)

		rol	a0,a0,8
		and	t1,a0,0xFF
		sb	t1,LED_CHAR3(t0)

	/*
	 * A0 is now the same value it was at the beginning.
	 */


#ifdef _SERIAL_PORT_LEDS_
		move	t3,ra
		move	t2,a0

		li	a0,'['
		bal	board_uarta_txchar

		move	a0,t2
		rol	a0,8
		bal	board_uarta_txchar

		rol	a0,8
		bal	board_uarta_txchar

		rol	a0,8
		bal	board_uarta_txchar

		rol	a0,8
		bal	board_uarta_txchar

		li	a0,']'
		bal	board_uarta_txchar
		li	a0,13
		bal	board_uarta_txchar
		li	a0,10
		bal	board_uarta_txchar

		move	ra,t3
#endif
		j	ra

END(board_setleds)