/* $OpenBSD: md_init.h,v 1.4 2013/12/04 00:20:31 deraadt Exp $ */

/*-
 * Copyright (c) 2001 Ross Harvey
 * Copyright (c) 2001 Simon Burge
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the NetBSD
 *      Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``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 FOUNDATION OR CONTRIBUTORS
 * 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.
 */

#define ra      "$31"

/*
 * Allocate 32 bytes for the stack frame.  Store GP at SP+16 (since
 * this is where code generated by the compiler for fallthru processing
 * expects it to be), and the RA at SP+24.
 */

/* this is gross... */

#ifdef __ABICALLS__
#define MD_FUNCTION_PROLOGUE(entry_pt)			\
	"	.frame $sp,32,$31		\n"	\
	"	.set	reorder			\n"	\
	"	dsubu    $sp,$sp,32		\n"	\
	"	.cpsetup $25, 16, "#entry_pt"	\n"	\
	"	sd      "ra",24($sp)		\n"
#else
#define MD_FUNCTION_PROLOGUE(entry_pt)			\
	"       dsubu	$sp,$sp,32		\n"	\
	"       sd	"ra",24($sp)		\n"
#endif


#define MD_SECTION_PROLOGUE(sect, entry_pt)		\
	__asm (						\
	".section "#sect",\"ax\",@progbits	\n"	\
	".align 2				\n"	\
	".globl "#entry_pt"			\n"	\
	".type "#entry_pt"@function		\n"	\
	".ent "#entry_pt"			\n"	\
	#entry_pt":				\n"	\
	MD_FUNCTION_PROLOGUE(entry_pt)			\
	"       /* fall thru */			\n"	\
	".previous")

#define MD_SECTION_EPILOGUE(sect)                       \
	__asm (						\
	".section "#sect",\"ax\",@progbits      \n"	\
	"	ld	"ra",24($sp)		\n"	\
	" # next should have been a .cpreturn 	\n"	\
	"	ld	$gp,16($sp)		\n"	\
	"	.set	noreorder		\n"	\
	"	j	"ra"			\n"	\
	"	daddu	$sp,$sp,32		\n"	\
	"	.set	reorder			\n"	\
	".previous")

#define MD_SECT_CALL_FUNC(section, func)		\
	__asm (".section "#section", \"ax\"	\n"	\
	"	jal	" #func "		\n"	\
	".previous")


struct kframe {
	long	kargc;
	char	*kargv[1];	/* size depends on kargc */
	char	kargstr[1];	/* size varies */
	char	kenvstr[1];	/* size varies */
};

#define	MD_START		__start
#define	MD_START_ARGS		void

/*
 * XXX no cleanup() callback passed to __start yet.  Need to pull
 * it from v0 in ASM? 
 */
#define	MD_NO_CLEANUP


/*
 * Do GP register setup and find the kframe struct. Differs depending
 * on shared lib stuff or not.
 * XXX just above the saved frame pointer?
 *	kfp = (struct kframe *) (&param-1);
 */
#if defined(_NO_ABICALLS)
#define	SETUP_KFP(kfp)					\
	asm("	dla	$28,_gp				\n" \
	"	daddiu	%0,$29,32" : "=r" (kfp))
#else
#define	SETUP_KFP(kfp)					\
	asm("	daddiu	%0,$29,48" : "=r" (kfp))
#endif


#define	MD_START_SETUP				\
	struct	kframe *kfp;			\
	char	**argv, **envp;			\
	int	argc;				\
						\
	SETUP_KFP(kfp);				\
	argc = kfp->kargc;			\
	argv = &kfp->kargv[0];			\
	environ = envp = argv + argc + 1;