hal_platform_setup.h

开放源码实时操作系统源码.

#ifndef CYGONCE_HAL_PLATFORM_SETUP_H
#define CYGONCE_HAL_PLATFORM_SETUP_H

/*=============================================================================
//
//      hal_platform_setup.h
//
//      Platform specific support for HAL (assembly code)
//
//=============================================================================
//####ECOSGPLCOPYRIGHTBEGIN####
// -------------------------------------------
// This file is part of eCos, the Embedded Configurable Operating System.
// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
// Copyright (C) 2003 Nick Garnett <[e-mail]>
//
// 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.
// -------------------------------------------
//####ECOSGPLCOPYRIGHTEND####
//=============================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):   gthomas
// Contributors:gthomas, tdrury, nickg, block
// Date:        2001-07-12
// Purpose:     AT91/phycore platform specific support routines
// Description:
// Usage:       #include <cyg/hal/hal_platform_setup.h>
//
//####DESCRIPTIONEND####
//
//===========================================================================*/

#include <cyg/hal/var_io.h>

//===========================================================================*/
                
        .macro  _led_init
        ldr     r0,=AT91_PIOA
        mov     r1,#0x00000001
        str     r1,[r0,#AT91_PIO_PER]
        str     r1,[r0,#AT91_PIO_OER]
        _led    0
        .endm
        
        .macro _led y
        ldr     r0,=AT91_PIOA
        mov     r1,#0x00000001
        str     r1,[r0,#AT91_PIO_SODR]
        mov     r1,#0x00000001
        str     r1,[r0,#AT91_PIO_CODR]
        .endm

        .macro  _pclock_init
        ldr     r0,=AT91_PMC            // Power saving interface
        ldr     r1,=0xFFFFFFFF          // Enable all peripheral [clocks]
        str     r1,[r0,#AT91_PMC_PCER]
        .endm

        .macro  _pio_init
        ldr     r0,=AT91_PIOA           // Disable PIO (so peripherals can use bits)
        ldr     r1,=(0x006d8000)          // Enable UARTS 0/1/2 to use pins
        str     r1,[r0,#AT91_PIO_PDR]
        .endm
                
#define CYGHWR_LED_MACRO _led \x

//===========================================================================*/
                        
#if defined(CYG_HAL_STARTUP_ROM) || defined(CYG_HAL_STARTUP_ROMRAM)

#define AT91_PMC_CGMR_INIT0     (AT91_PMC_CGMR_MOSC_XTAL        |       \
                                AT91_PMC_CGMR_MOSC_ENA          |       \
                                AT91_PMC_CGMR_OSC_CNT(47))

#define AT91_PMC_CGMR_INIT1     (AT91_PMC_CGMR_INIT0            |       \
                                AT91_PMC_CGMR_CSS_MOSC)

#define AT91_PMC_CGMR_INIT2     (AT91_PMC_CGMR_INIT1            |       \
                                AT91_PMC_CGMR_PLL_MUL(1)        |       \
                                AT91_PMC_CGMR_PLL_CNT(255))

#define AT91_PMC_CGMR_INIT3     (AT91_PMC_CGMR_INIT0            |       \
                                AT91_PMC_CGMR_PLL_MUL(1)        |       \
                                AT91_PMC_CGMR_PLL_CNT(3)        |       \
                                AT91_PMC_CGMR_CSS_PLL)
                                                        
        .macro  _setup
        _led_init

        // Change system frequency from 32kHz to 32MHz.
        
        // First enable the master oscillator to run at 16MHz from
        // external crystal.
        ldr     r2,=AT91_PMC
        ldr     r3,=AT91_PMC_CGMR_INIT0
        str     r3,[r2,#AT91_PMC_CGMR]

        // Wait for MOSC to stabilize.
        mov     r4,#AT91_PMC_SR_MOSCS
1:
        ldr     r3,[r2,#AT91_PMC_SR]
        and     r3,r4,r3
        cmp     r3,r4 //#AT91_PMC_SR_MOSCS
        bne     1b

        // Now switch CPU clock to use master oscillator, after this we
        // should be running at 16MHz.
        ldr     r3,=AT91_PMC_CGMR_INIT1
        str     r3,[r2,#AT91_PMC_CGMR]

        // Now enable PLL to run at twice MOSC frequency
        ldr     r3,=AT91_PMC_CGMR_INIT2
        str     r3,[r2,#AT91_PMC_CGMR]

        // Wait for PLL to stabilize
        mov     r4,#AT91_PMC_SR_LOCK
2:
        ldr     r3,[r2,#AT91_PMC_SR]
        and     r3,r4,r3
        cmp     r3,r4
        bne     2b

        // Finally, switch CPU clock from MOSC to PLL 
        ldr     r3,=AT91_PMC_CGMR_INIT3
        str     r3,[r2,#AT91_PMC_CGMR]

        // All done, we should be running at 32MHz now
        
        ldr     r10,=_InitMemory        // Initialize memory controller
        movs    r0,pc,lsr #20           // If ROM startup, PC < 0x100000
        moveq   r10,r10,lsl #12         //   mask address to low 20 bits
        moveq   r10,r10,lsr #12
        ldmia   r10!,{r0-r9,r11-r12}    // Table of initialization constants
#if defined(CYG_HAL_STARTUP_ROMRAM)
        ldr     r10,=0x0000FFFF
        and     r12,r12,r10
        ldr     r10,=0x01000000
        orr     r12,r12,r10
#endif
        stmia   r11!,{r0-r9}            // Write to controller
        mov     pc,r12                  // Change address space, break pipeline
_InitMemory:
        .long   0x01002529  // 0x01000000, 16MB,  2 cycles  after transfer, 16-bit, 6 wait states
        .long   0x020034A5  // 0x02000000, 16MB,  0 cycles after transfer, 16-bit, 1 wait state
        .long   0x20000000  // unused
        .long   0x30000000  // unused
        .long   0x40000000  // unused
        .long   0x50000000  // unused
        .long   0x60000000  // unused
        .long   0x70000000  // unused
        .long   0x00000001  // REMAP command
        .long   0x00000000  // Standard read protocol
        .long   AT91_EBI    // External Bus Interface address
        .long   10f         // address where to jump
10:
#if defined(CYG_HAL_STARTUP_ROMRAM)
        ldr     r0,=0x01000000          // Relocate FLASH/ROM to on-chip RAM
        ldr     r1,=0x02000000          // RAM base & length
        ldr     r2,=0x04200000
20:     ldr     r3,[r0],#4
        str     r3,[r1],#4
        cmp     r1,r2
        bne     20b
        ldr     r0,=30f
        mov     pc,r0
30:
#endif
        _pclock_init
        _pio_init
        .endm

#define CYGSEM_HAL_ROM_RESET_USES_JUMP

#else

        .macro  _setup
        _led_init
        _pclock_init
        _pio_init        
        .endm
        
#endif

#define PLATFORM_SETUP1     _setup

        
//-----------------------------------------------------------------------------
// end of hal_platform_setup.h
#endif // CYGONCE_HAL_PLATFORM_SETUP_H