/******************************************************************************
Copyright (C) 2013, Freie Universitaet Berlin (FUB). All rights reserved.

These sources were developed at the Freie Universitaet Berlin, Computer Systems
and Telematics group (http://cst.mi.fu-berlin.de).
-------------------------------------------------------------------------------
This file is part of RIOT.

This file is subject to the terms and conditions of the LGPLv2.
See the file LICENSE in the top level directory for more details.
*******************************************************************************/

#include "cpu.h"
#include "kernel.h"
#include "kernel_internal.h"
#include "sched.h"
#include "thread.h"

volatile int __inISR = 0;

char __isr_stack[MSP430_ISR_STACK_SIZE];

void thread_yield()
{
    __save_context();

    dINT();
    /* have active_thread point to the next thread */
    sched_run();
    eINT();

    __restore_context();
}

void cpu_switch_context_exit(void)
{
    active_thread = sched_threads[0];
    sched_run();

    __restore_context();
}

/**
 * mspgcc handles main specially - it does not return but falls
 * through to section .fini9.
 * To "fix" this, we put a return in section .fini9 to make main
 * behave like a regular function. This enables a common
 * thread_stack_init behavior. */
__attribute__((section (".fini9"))) void __main_epilogue(void) { __asm__("ret"); }

//----------------------------------------------------------------------------
// Processor specific routine - here for MSP
//----------------------------------------------------------------------------
char *thread_stack_init(void (*task_func)(void), void *stack_start, int stack_size)
{
    unsigned short *stk;

    /* XXX: work around for misalignment, remove once solved properly in thread.c */
    stack_size--;

    stk = (unsigned short *)(stack_start + stack_size);

    *stk = (unsigned short) sched_task_exit;
    --stk;

    *stk = (unsigned short) task_func;
    --stk;

    /* initial value for SR */

    *stk = GIE;
    --stk;

    /* Space for registers. */
    for (unsigned int i = 15; i > 4; i--) {
        *stk = i;
        --stk;
    }

    //stk -= 11;

    return (char *) stk;
}

int inISR()
{
    return __inISR;
}