c_init.c

/*
Copyright (c) 2015 Intel Corporation.  All right reserved.

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library 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
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

*/
#include <stdint.h>
#include <string.h>

#include "interrupt.h"
#include "arcv2_timer0.h"

/* Application main() function prototype */
extern int main (void);

/* C++ constructor function prototype */
typedef void (*cpp_ctor_fn) (void);
/* C++ constructor list */
extern cpp_ctor_fn __CTOR_LIST__[];

/* BSS section markers */
extern char __bss_start[];
extern char __bss_end[];

/* DATA section markers */
extern char __data_rom_start[];
extern char __data_ram_start[];
extern char __data_ram_end[];

static void _exec_ctors (void)
{
    unsigned long i, nctors = (unsigned long)(__CTOR_LIST__[0]);

    for (i = nctors; i > 0; i--)
        __CTOR_LIST__[i]();
}

 __attribute__((__noreturn__)) void _main (void)
{
    /* Zero BSS section */
    memset(__bss_start, 0, __bss_end - __bss_start);
    /* Relocate DATA section to RAM */
    memcpy(__data_ram_start, __data_rom_start, __data_ram_end - __data_ram_start);
    /* Execute C++ Constructors */
    _exec_ctors();
    /* Init the the interrupt unit device - disable all the interrupts; The
     * default value of IRQ_ENABLE is 0x01 for all configured interrupts */
    interrupt_unit_device_init();
    /* Start the system's virtual 64-bit Real Time Counter */
    timer0_driver_init();
    /* Jump to application main() */
    main ();
    /* Never reached */
    __builtin_unreachable();
}