platform.s

eCos操作系统源码

##
#=============================================================================
##	platform.S
##
##	MIPS Atlas platform code
##
##=============================================================================
#####ECOSGPLCOPYRIGHTBEGIN####
## -------------------------------------------
## This file is part of eCos, the Embedded Configurable Operating System.
## Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
##
## eCos 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 or (at your option) any later version.
##
## eCos 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 eCos; if not, write to the Free Software Foundation, Inc.,
## 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
##
## As a special exception, if other files instantiate templates or use macros
## or inline functions from this file, or you compile this file and link it
## with other works to produce a work based on this file, this file does not
## by itself cause the resulting work to be covered by the GNU General Public
## License. However the source code for this file must still be made available
## in accordance with section (3) of the GNU General Public License.
##
## This exception does not invalidate any other reasons why a work based on
## this file might be covered by the GNU General Public License.
##
## Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.
## at http://sources.redhat.com/ecos/ecos-license/
## -------------------------------------------
#####ECOSGPLCOPYRIGHTEND####
##=============================================================================
#######DESCRIPTIONBEGIN####
##
## Author(s):	dmoseley
## Contributors:	dmoseley
## Date:	2000-06-06
## Purpose:	MIPS Atlas platform code
## Description:	Platform specific code for Atlas board.
##
##
##
##
######DESCRIPTIONEND####
##
##=============================================================================

#include <pkgconf/system.h>
#include <pkgconf/hal.h>

#ifdef CYGPKG_KERNEL
# include <pkgconf/kernel.h>
#endif

#include <cyg/hal/arch.inc>
#include <cyg/hal/plf_io.h>
#include <cyg/hal/hal_arch.h>

##-----------------------------------------------------------------------------

##-----------------------------------------------------------------------------
# Platform Initialization.
# This code performs platform specific initialization.

##-----------------------------------------------------------------------------
## MEMC initialization.
##

#if defined(CYG_HAL_STARTUP_ROM) || defined(CYG_HAL_STARTUP_ROMRAM)

	.text
	.set	noreorder


.macro MASK_WRITE_PCI_REG regnum, devnum, mask
	.set noreorder
	# First, read the appropriate register
	li	t0, HAL_GALILEO_PCI0_CONFIG_ADDR_ConfigEn | \regnum | \devnum
	sw	t0, HAL_GALILEO_PCI0_CONFIG_ADDR_OFFSET(s7)
	lw	t1, HAL_GALILEO_PCI0_CONFIG_DATA_OFFSET(s7)

	# Now, mask in the appropriate bits
	li	t2, \mask
	or	t1, t2

	# Write the updated value
	li	t0, HAL_GALILEO_PCI0_CONFIG_ADDR_ConfigEn | \regnum | \devnum
	sw	t0, HAL_GALILEO_PCI0_CONFIG_ADDR_OFFSET(s7)
	sw	t1, HAL_GALILEO_PCI0_CONFIG_DATA_OFFSET(s7)
.endm

.macro WRITE_PCI_REG regnum, devnum, base
	.set noreorder
	li	t0, HAL_GALILEO_PCI0_CONFIG_ADDR_ConfigEn | \regnum | \devnum
	li	t1, \base
	sw	t0, HAL_GALILEO_PCI0_CONFIG_ADDR_OFFSET(s7)
	sw	t1, HAL_GALILEO_PCI0_CONFIG_DATA_OFFSET(s7)
.endm

#define NO_MASK        0
#define NO_ERROR_CHECK 0
#define ERROR_CHECK    1
.macro READ_SPD_VALUE func, mask, ret_reg, err_check
	.set noreorder
	jal	read_spd_value
	li	a0, \func			 # delay slot
.if \err_check
	beq	v0, zero, error
	nop
.endif
	move	\ret_reg, v0
.if \mask
	and	\ret_reg, \mask
.endif
.endm

##-----------------------------------------------------------------------------
##
## Initialize the RAM.
##
## To do that, we need to first initialize the Galileo PCI stuff to gain access
## to the SAA9730.
## From there, use the I2C bus of the SAA9730 to read the SPD SDRAM
## config data. We then setup the Galileo SDRAM configuration
##
##  Returns
##  v0 = Error Code
##  v1 = SDRAM size
##
FUNC_START(hal_atlas_init_sdram)

	.set noreorder

	# Save the return address
	move	s8, ra

	# Setup the base address registers
	li	s7, CYGARC_UNCACHED_ADDRESS(HAL_GALILEO_REGISTER_BASE)

	# Setup the Galileo controller Endian configuration
	li	t0, (HAL_GALILEO_BYTE_SWAP)
	sw	t0, HAL_GALILEO_PCI_INTERNAL_COMMAND_OFFSET(s7)

	# Setup the PCI_0 Timeout and retry configuration
	li	t0, HAL_GALILEO_PCI0_TIMEOUT_RETRY_VALUE
	sw	t0, HAL_GALILEO_PCI0_TIMEOUT_RETRY_OFFSET(s7)

	# Setup Galileo as PCI Master
	MASK_WRITE_PCI_REG HAL_GALILEO_PCI0_STATUS_COMMAND_REGNUM, HAL_ATLAS_NULL_DEVNUM, \
			   (HAL_GALILEO_PCI0_CONFIG_MEMEn | HAL_GALILEO_PCI0_CONFIG_MasEn | HAL_GALILEO_PCI0_CONFIG_SErrEn)

	# Setup Galileo PCI latency timer
	MASK_WRITE_PCI_REG HAL_GALILEO_PCI0_BIST_REGNUM, HAL_ATLAS_NULL_DEVNUM, \
			   HAL_GALILEO_PCI0_LAT_TIMER_VAL

	# Setup base address for SAA9730
	WRITE_PCI_REG HAL_GALILEO_PCI0_SCS32_BASE_REGNUM, HAL_ATLAS_SAA9730_DEVNUM, \
		      CYGARC_PHYSICAL_ADDRESS(HAL_GALILEO_PCI0_MEM0_BASE)

	# Setup SAA9730 command and status register
	MASK_WRITE_PCI_REG HAL_GALILEO_PCI0_STATUS_COMMAND_REGNUM, HAL_ATLAS_SAA9730_DEVNUM, \
			   (HAL_GALILEO_PCI0_CONFIG_MEMEn | HAL_GALILEO_PCI0_CONFIG_SErrEn)

	# Init the I2C controller
	li	t0, HAL_SAA9730_I2CSC_I2CCC_6400
	li	t1, CYGARC_UNCACHED_ADDRESS(HAL_GALILEO_PCI0_MEM0_BASE)
	sw	t0, HAL_SAA9730_I2CSC_OFFSET(t1)

	##=====================================================================================
	##
	## Read the SPD device parameters and determine memory size
	##
	READ_SPD_VALUE HAL_SPD_GET_NUM_ROW_BITS, 0xf, s0, ERROR_CHECK
	READ_SPD_VALUE HAL_SPD_GET_NUM_COL_BITS, 0xf, s1, ERROR_CHECK
	READ_SPD_VALUE HAL_SPD_GET_NUM_DEVICE_BANKS, NO_MASK, s2, ERROR_CHECK

	READ_SPD_VALUE HAL_SPD_GET_SDRAM_WIDTH, 0x7f, s3, ERROR_CHECK
	READ_SPD_VALUE HAL_SPD_GET_NUM_MODULE_BANKS, NO_MASK, s4, ERROR_CHECK
	READ_SPD_VALUE HAL_SPD_GET_ROW_DENSITY, NO_MASK, s5, ERROR_CHECK

	#
	# Determine Size
	#     SIZE = SDRAM_WIDTH * NUM_DEVICE_BANKS * 2 ^ (NUM_ROW_BITS + NUM_COL_BITS)
	#
	addu	t0, s0, s1		# t0 = (NUM_ROW_BITS + NUM_COL_BITS)
	li	t1, 1			# t1 = 2 ^ 0
	sll	t1, t0			# t1 = 2 ^ (NUM_ROW_BITS + NUM_COL_BITS)
	multu	s2, t1
	mflo	s6			# s6 = NUM_DEVICE_BANKS * 2 ^ (NUM_ROW_BITS + NUM_COL_BITS)
	nop
	nop
	nop
	multu	s6, s3
	mflo	s6			# s6 = SDRAM_WIDTH * NUM_DEVICE_BANKS * 2 ^ (NUM_ROW_BITS + NUM_COL_BITS)
	nop
	nop
	nop

	#
	# Determine size of Bank 0
	#
	li	s0, HAL_ATLAS_MAX_BANKSIZE
0:
	and	t1, s5, BIT7
	bnez	t1, 8f
	sll	s5, 1
	b	0b
	srl	s0, 1
8:

	#
	# Determine if Bank 1 exists
	#
	li	t0, 1
	beq	s4, t0, 8f
	move	s1, zero
	#
	# Determine if Bank 1 is different than Bank 0
	#
	and	t1, s5, 0xFF
	beq	t1, zero, 8f
	move	s1, s0
	#
	# Determine size of Bank 1
	#
	li	s1, HAL_ATLAS_MAX_BANKSIZE
0:
	and	t1, s5, BIT7
	bnez	t1, 8f
	sll	s5, 1
	b	0b
	srl	s1, 1
8:

	#
	# FIXME: We should probably do some validation on the various
	#	 memory parameters here at some point.
	#

	#
	# Set the base SDRAM bank configuration value.
	# All other fields are zero, and the proper value is masked
	# in when they are known
	#
	li	s5, HAL_GALILEO_SDRAM_SRAS_TO_SCAS_DELAY_3C | \
		    HAL_GALILEO_SDRAM_WIDTH_64BIT | \
		    HAL_GALILEO_SDRAM_SRAS_PRECHARGE_3C

	#
	# Setup the CASLAT value.
	# Support only CASLAT = 2
	#
	READ_SPD_VALUE HAL_SPD_GET_CAS_LAT, NO_MASK, v0, NO_ERROR_CHECK
	and	t0, v0, 2
	beqz	t0, error
	nop
	ori	s5, HAL_GALILEO_SDRAM_BANK0_CASLAT_2

	#
	# Setup SDRAM device size
	#
	li	t0, SZ_16M
	beq	s6, t0, 8f
	nop
	ori	s5, HAL_GALILEO_SDRAM_BANK0_SZ_64M
8:

	#
	# Setup burst length: Support only 8
	#
	READ_SPD_VALUE HAL_SPD_GET_BURST_LENGTH, NO_MASK, v0, NO_ERROR_CHECK
	and	t0, v0, 8
	beqz	t0, error
	nop

	#
	# Setup Parity.
	# Only support Parity/Noparity.	 Don't support ECC.
	#
	READ_SPD_VALUE HAL_SPD_GET_CONFIG_TYPE, NO_MASK, v0, NO_ERROR_CHECK
	li	t0, HAL_SPD_CONFIG_TYPE_PARITY
	beq	t0, v0, 0f
	nop
	li	t0, HAL_SPD_CONFIG_TYPE_ECC
	beq	t0, v0, error