Subversion Repositories openrisc_2011-10-31

##=============================================================================
##
##      variant.S
##
##      MIPS uPD9875xx device 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):   hmt, nickg
## Contributors:nickg
## Date:        2001-05-25
## Purpose:     NEC MIPS uPD985xx device code
## Description: Device specific code
##              
##              
##              
##
######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/var_arch.h>

##-----------------------------------------------------------------------------
## MMU setup.
## Some of this code is taken from the PMON sources, hence it does not fully
## conform to our normal coding conventions.

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

// There is none.  We can access all areas via kseg[01] so we are happy
// with no MMU setup.

#endif
        
##-----------------------------------------------------------------------------
## MEMC initialization.
## This also initializes the PCI bus and ISA bus bridge, so at the end of this
## we should have full access to all the memory and devices we need.
## This code is table driven, which is somewhat more compact that coding it all.
## Table entries consist of an address and a value to store in that address.
## A zero address terminates the table. Two special address values modify the
## behaviour:   
## DELAY_LOOP   loops for the number of iterations in the value field.
## WRITE16      treats the next 2 words as an address and value to be written 
##              with a 16 bit write cycle.
        
#if defined(CYG_HAL_STARTUP_ROM) || defined(CYG_HAL_STARTUP_ROMRAM)
        
#define DELAY_LOOP      1
#define WRITE16         2       

                
FUNC_START(hal_memc_setup)

        lar     t0,hal_memc_setup_table
        la      t1,0xbfc00000
        la      t2,DELAY_LOOP
        la      t3,WRITE16
1:      
        lw      a0,0(t0)        # next table entry
        lw      a1,4(t0)        # value to write
        addiu   t0,8            # go to next entry
        beq     a0,t2,2f        # Check for delay
        nop
        beq     a0,t3,3f        # Check for 16 bit write
        nop
        beqz    a0,9f           # zero terminates loop
        nop
        sw      a1,0(a0)        # write it
        lw      zero,0(t1)      # uncached read to flush write buffer
        b       1b
        nop
2:
        lw      zero,0(t1)      # uncached read to flush write buffer   
        bnez    a1,2b           # count down by value in a1
        addiu   a1,-1           # decrement in delay slot
        b       1b              # go back to loop
        nop
3:      
        lw      a3,0(t0)        # get next word
        addiu   t0,4            # skip it
        sh      a3,0(a1)        # store halfword        
        lw      zero,0(t1)      # uncached read to flush write buffer
        b       1b
        nop
9:
        jr      ra
        nop

FUNC_END(hal_memc_setup)        

##----------------------------------------------------------------------------- 
##-----------------------------------------------------------------------------
## The initialization table
        
hal_memc_setup_table:   
        .long   DELAY_LOOP,     0x00010000      # Wait for HW to settle

        .long   RMMDR_ADR,      RMMDR_28F640
        .long   RMATR_ADR,      RMATR_28F640

        .long   DELAY_LOOP,     0x00010000      # Wait for HW to settle
                
        .long   SDMDR_ADR,      SDMDR_INIT
        .long   SDTSR_ADR,      SDTSR_INIT
        .long   SDPTR_ADR,      SDPTR_INIT
        .long   SDRMR_ADR,      SDRMR_INIT
        
        .long   DELAY_LOOP,     0x00010000      # Wait for HW to settle
                
        .long   0,              0


#endif
                
##-----------------------------------------------------------------------------
## end of platform.S