source: rtems/c/src/lib/libbsp/powerpc/mpc55xxevb/startup/bspstart.c @ d4886a06

/**
 * @file
 *
 * @ingroup mpc55xx
 *
 * @brief BSP startup code.
 */

/*
 * Copyright (c) 2008
 * Embedded Brains GmbH
 * Obere Lagerstr. 30
 * D-82178 Puchheim
 * Germany
 * rtems@embedded-brains.de
 *
 * The license and distribution terms for this file may be found in the file
 * LICENSE in this distribution or at http://www.rtems.com/license/LICENSE.
 */

#include <mpc55xx/mpc55xx.h>
#include <mpc55xx/regs.h>
#include <mpc55xx/edma.h>

#include <rtems.h>
#include <rtems/bspIo.h>
#include <rtems/libcsupport.h>

#include <libcpu/powerpc-utility.h>

#include <bsp.h>
#include <bsp/bootcard.h>
#include <bsp/irq.h>
#include <bsp/irq-generic.h>
#include <bsp/ppc_exc_bspsupp.h>

#define RTEMS_STATUS_CHECKS_USE_PRINTK

#include <rtems/status-checks.h>

#define DEBUG_DONE() DEBUG_PRINT( "Done\n")

#define MPC55XX_INTERRUPT_STACK_SIZE 0x1000

/* Symbols defined in linker command file */
LINKER_SYMBOL( bsp_ram_start);
LINKER_SYMBOL( bsp_ram_end);
LINKER_SYMBOL( bsp_external_ram_start);
LINKER_SYMBOL( bsp_external_ram_size);
LINKER_SYMBOL( bsp_section_bss_end);

unsigned int bsp_clock_speed = 0;

uint32_t bsp_clicks_per_usec = 0;

void BSP_panic( char *s)
{
        rtems_interrupt_level level;

        rtems_interrupt_disable( level);

        printk( "%s PANIC %s\n", _RTEMS_version, s);

        while (1) {
                /* Do nothing */
        }
}

void _BSP_Fatal_error( unsigned n)
{
        rtems_interrupt_level level;

        rtems_interrupt_disable( level);

        printk( "%s PANIC ERROR %u\n", _RTEMS_version, n);

        while (1) {
                /* Do nothing */
        }
}

void bsp_get_work_area( void **work_area_start, size_t *work_area_size, void **heap_start, size_t *heap_size)
{
        *work_area_start = bsp_section_bss_end;
        *work_area_size = bsp_ram_end - 2 * MPC55XX_INTERRUPT_STACK_SIZE - bsp_section_bss_end;
        *heap_start = bsp_external_ram_start;
        *heap_size = (size_t) bsp_external_ram_size;
}

void bsp_pretasking_hook()
{
#ifdef STACK_CHECKER_ON
        Stack_check_Initialize();
#endif
}

void bsp_predriver_hook()
{
        rtems_status_code sc = RTEMS_SUCCESSFUL;

        DEBUG_PRINT( "Initialize eDMA ...\n");
        sc = mpc55xx_edma_init();
        if (sc != RTEMS_SUCCESSFUL) {
                BSP_panic( "Cannot initialize eDMA");
        } else {
                DEBUG_DONE();
        }
}

static void mpc55xx_ebi_init()
{
        struct EBI_CS_tag cs = { BR : MPC55XX_ZERO_FLAGS, OR : MPC55XX_ZERO_FLAGS };
        union SIU_PCR_tag pcr = MPC55XX_ZERO_FLAGS;
        int i = 0;

        /* External SRAM (0 wait states, 512kB, 4 word burst) */
        cs.BR.B.BA = 0;
        cs.BR.B.PS = 1;
        cs.BR.B.BL = 1;
        cs.BR.B.WEBS = 0;
        cs.BR.B.TBDIP = 0;
        cs.BR.B.BI = 1; /* TODO: Enable burst */
        cs.BR.B.V = 1;

        cs.OR.B.AM = 0x1fff0;
        cs.OR.B.SCY = 0;
        cs.OR.B.BSCY = 0;

        EBI.CS [0] = cs;

        /* !CS [0] */
        SIU.PCR [0].R = 0x443;

        /* ADDR [8 : 31] */
        for (i = 4; i < 4 + 24; ++i) {
                SIU.PCR [i].R = 0x440;
        }

        /* DATA [0 : 15] */
        for (i = 28; i < 28 + 16; ++i) {
                SIU.PCR [i].R = 0x440;
        }

        /* RD_!WR */
        SIU.PCR [62].R = 0x443;

        /* !BDIP */
        SIU.PCR [63].R = 0x443;

        /* !WE [0 : 3] */
        for (i = 64; i < 64 + 4; ++i) {
                SIU.PCR [i].R = 0x443;
        }

        /* !OE */
        SIU.PCR [68].R = 0x443;

        /* !TS */
        SIU.PCR [69].R = 0x443;
}

/**
 * @brief Start BSP.
 */
void bsp_start(void)
{
        ppc_cpu_id_t myCpu;
        ppc_cpu_revision_t myCpuRevision;

        uint32_t interrupt_stack_start = bsp_ram_end - 2 * MPC55XX_INTERRUPT_STACK_SIZE;
        uint32_t interrupt_stack_size = MPC55XX_INTERRUPT_STACK_SIZE;

        /* ESCI pad configuration */
        SIU.PCR [89].R = 0x400;
        SIU.PCR [90].R = 0x400;

        DEBUG_PRINT( "BSP start ...\n");

        DEBUG_PRINT( "System clock          : %i\n", mpc55xx_get_system_clock());
        DEBUG_PRINT( "Memory start          : 0x%08x\n", bsp_ram_start);
        DEBUG_PRINT( "Memory end            : 0x%08x\n", bsp_ram_end);
        DEBUG_PRINT( "Memory size           : 0x%08x\n", bsp_ram_end - bsp_ram_start);
        DEBUG_PRINT( "Interrupt stack start : 0x%08x\n", interrupt_stack_start);
        DEBUG_PRINT( "Interrupt stack end   : 0x%08x\n", interrupt_stack_start + interrupt_stack_size);
        DEBUG_PRINT( "Interrupt stack size  : 0x%08x\n", interrupt_stack_size);
        
        /*
         * Get CPU identification dynamically. Note that the get_ppc_cpu_type()
         * function store the result in global variables so that it can be used
         * latter...
         */
        myCpu = get_ppc_cpu_type();
        myCpuRevision = get_ppc_cpu_revision();
        
        /* Time reference value */
        bsp_clicks_per_usec = bsp_clock_speed / 1000000;

        /* Initialize External Bus Interface */
        mpc55xx_ebi_init();
        
        /* Initialize exceptions */
        DEBUG_PRINT( "Initialize exceptions ...\n");
        ppc_exc_initialize( PPC_INTERRUPT_DISABLE_MASK_DEFAULT, interrupt_stack_start, interrupt_stack_size);
        DEBUG_DONE();

        /* Initialize interrupts */
        DEBUG_PRINT( "Initialize interrupts ...\n");
        if (bsp_interrupt_initialize() != RTEMS_SUCCESSFUL) {
                BSP_panic( "Cannot initialize interrupts");
        } else {
                DEBUG_DONE();
        }
        
        DEBUG_PRINT( "BSP start done\n");

        return;

        /* TODO */
        /*
        * Enable instruction and data caches. Do not force writethrough mode.
        */
#if INSTRUCTION_CACHE_ENABLE
        rtems_cache_enable_instruction();
#endif
#if DATA_CACHE_ENABLE
        rtems_cache_enable_data();
#endif
}

/**
 * @brief Idle thread body.
 */
Thread _Thread_Idle_body( uint32_t ignored)
{

        while (1) {
                asm volatile(
                        "mfmsr 3;"
                        "oris 3,3,4;"
                        "sync;"
                        "mtmsr 3;"
                        "isync;"
                        "ori 3,3,0;"
                        "ori 3,3,0"
                );
        }
        return 0;
}