taskinit.c

来自「VRTX操作系统」· C语言 代码 · 共 54 行

/*************************************************************************

	Copyright (c) 1999 Mentor Graphics Corporation.


IMPORTANT - USE OF THIS SOFTWARE IS SUBJECT TO LICENSE RESTRICTIONS
CAREFULLY READ THE LICENSE AGREEMENT BEFORE USING THE SOFTWARE


*************************************************************************/

/* %M% - Allocates and initilizes the stack of a new thread */

#include "task.h"
#include "kernel.h"
#include "processor.h"

/*---------------------------------------------------------------------------*/
/*
 * vmc_taskinit - Initializes the stack and start address for the thread.
 */

extern	void	vmc_ARMTaskStartup(void);

#define	StackSlop	256

void vmc_taskinit(tcbp, stk, stksize, taskaddr, arg)
struct tentry  *tcbp;
char *stk;
int stksize;
void (*taskaddr)(void *);
int arg;
{
	struct vmc_frame *frame;

  tcbp->pregs = ((char *) stack_align(stk+stksize)) - sizeof(struct vmc_frame);
  		/* Initialize stack pointer */
  frame = (struct vmc_frame *) (tcbp->pregs);
  frame->cpsr = SVCMode;	/* Supervisor32 mode, IRQ & FIQ enable */
  frame->r4 = 0;
  frame->r5 = 0;
  frame->r6 = 0;
  frame->r7 = 0;
  frame->r8 = 0;
  frame->r9 = 0;				/* sb - stack base */
  frame->r10 = (int) (stk + StackSlop);		/* sl - stack limit */
  frame->r11 = 0;				/* fp - frame pointer */
  frame->startup_pc = vmc_ARMTaskStartup;
  frame->task_arg = arg;
  frame->return_pc = vmc_userexit_ptr;
  frame->task_pc = taskaddr;
}
/*---------------------------------------------------------------------------*/