platinit.c

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/* platinit.c - platinit */

#include <xinu.h>

/*------------------------------------------------------------------------
 *  counterinit  -  Initialize the ARM performance counters
 *------------------------------------------------------------------------
 */
void        counterinit()
{
    /* Program the performance-counter control-register:        */
    /*  Enable all counters:                    */
    asm volatile ("MCR p15, 0, %0, c9, c12, 0\t\n" :: "r"
                            (0x00000011));

    /* Program the count enable set control-register:       */
    /*  Enable all counters:                    */
    asm volatile ("MCR p15, 0, %0, c9, c12, 1\t\n" :: "r"
                            (0x80000003));

    /* Program the overflow flag status-register:           */
    /*  Clear overflows:                    */
    asm volatile ("MCR p15, 0, %0, c9, c12, 3\t\n" :: "r"
                            (0x80000003));
}

/*------------------------------------------------------------------------
 * platinit - platform specific initialization for BeagleBone Black
 *------------------------------------------------------------------------
 */
void    platinit(void)
{

    struct  uart_csreg *uptr;   /* Address of UART's CSRs   */
    struct  watchdog_csreg *wdtptr; /* Watchdog registers       */

    /* Disable the watchdog timer */

    wdtptr = (struct watchdog_csreg *)WDTADDR;
    wdtptr->wspr = 0x0000aaaa;
    while(wdtptr->wwps & 0x00000010);
    wdtptr->wspr = 0x00005555;
    while(wdtptr->wwps & 0x00000010);

    /* Initialize the Interrupt Controller */

    initintc();

    /* Initialize the Performance Counters */

    counterinit();

    /* Pad control for CONSOLE */

    am335x_padctl(UART0_PADRX_ADDR,
            AM335X_PADCTL_RXTX | UART0_PADRX_MODE);
    am335x_padctl(UART0_PADTX_ADDR,
            AM335X_PADCTL_TX | UART0_PADTX_MODE);

    /* Reset the UART device */

    uptr = (struct uart_csreg *)devtab[CONSOLE].dvcsr;
    uptr->sysc |= UART_SYSC_SOFTRESET;
    while((uptr->syss & UART_SYSS_RESETDONE) == 0);
}