/*
 * Copyright (c) 2001-2004 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup ia32	
 * @{
 */
/** @file
 */

#ifndef KERN_ia32_CONTEXT_H_
#define KERN_ia32_CONTEXT_H_

#ifdef KERNEL
#include <arch/types.h>

#define STACK_ITEM_SIZE	4

/*
 * Both context_save() and context_restore() eat two doublewords from the stack.
 * First for pop of the saved register, second during ret instruction.
 *
 * One item is put onto stack to support get_stack_base().
 */
#define SP_DELTA	(8 + STACK_ITEM_SIZE)

#define context_set(c, _pc, stack, size) \
	do { \
		(c)->pc = (uintptr_t) (_pc); \
		(c)->sp = ((uintptr_t) (stack)) + (size) - SP_DELTA; \
		(c)->ebp = 0; \
	} while (0)

#endif /* KERNEL */

/*
 * Only save registers that must be preserved across
 * function calls.
 */
typedef struct {
	uintptr_t sp;
	uintptr_t pc;
	uint32_t ebx;
	uint32_t esi;
	uint32_t edi;
	uint32_t ebp;
	ipl_t ipl;
} __attribute__ ((packed)) context_t;

#endif

/** @}
 */
