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////////////////////////////////////////////////////////////////////////////////

//

// Filename:    taskp.c

//

// Project:     CMod S6 System on a Chip, ZipCPU demonstration project

//

// Purpose:     Implements the new_task function to create a new task, as well

//              as the idle_task's entry function and body.

//

// Creator:     Dan Gisselquist, Ph.D.

//              Gisselquist Technology, LLC

//

////////////////////////////////////////////////////////////////////////////////

//

// Copyright (C) 2015-2016, Gisselquist Technology, LLC

//

// This program is free software (firmware): 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 3 of the License, or (at

// your option) any later version.

//

// This program is distributed in the hope that it will be useful, but WITHOUT

// ANY WARRANTY; without even the implied warranty of MERCHANTIBILITY 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 this program.  (It's in the $(ROOT)/doc directory, run make with no

// target there if the PDF file isn't present.)  If not, see

// <http://www.gnu.org/licenses/> for a copy.

//

// License:     GPL, v3, as defined and found on www.gnu.org,

//              http://www.gnu.org/licenses/gpl.html

//

//

////////////////////////////////////////////////////////////////////////////////

//

//

#include "ksched.h"

#include "kfildes.h"

#include "taskp.h"

extern  void *sys_malloc(int sz);

TASKP   new_task(unsigned ln, VENTRYP entry) {

        int     i;

        TASKP   tsk = (TASKP)sys_malloc(sizeof(struct TASK_S)+ln);

        for(i=0; (unsigned)i<sizeof(struct TASK_S)+ln; i++)

                ((unsigned int *)tsk)[i] = 0;

        tsk->context[ 0] = (int)((long)(int *)idle_task);

        tsk->context[12] = (int)&tsk->user_data[ln]; // Set the stack pointer

        tsk->context[13] = (int)&tsk->user_data[ln]; // Set the stack pointer

        tsk->context[14] = 0x20; // GIE bit only

        tsk->context[15] = (int)((long)(int *)entry);

        tsk->user_heap   = &tsk->user_data[0];

        tsk->state = SCHED_READY;

        return tsk;

}

// 

// zip_idle is really an assembly language builtin.  It translates into the

// WAIT (i.e. for interrupt) instruction.  Even this, though, is a derived

// instruction.  More specifically, the WAIT instruction OR's a constant

// to the CC register.

//

extern void zip_idle(void);

void    idle_task(void) {

        do {

                zip_idle();

        } while(1);

}