/*
 * Copyright (c) 2020 Ariadne Conill <ariadne@dereferenced.org>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * This software is provided 'as is' and without any warranty, express or
 * implied.  In no event shall the authors be liable for any damages arising
 * from the use of this software.
 */

#include "defs.h"

ALIAS(setcontext, libucontext_setcontext)

FUNC(libucontext_setcontext)
	mov	r4, r0

	add	#(REG_OFFSET(REG_PC)), r0			/* restore PR */
	mov.l	@r0+, r2
	lds.l	@r0+, pr

	mov.l	@r0+, r1					/* restore T-flag */
	shlr	r1

	add	#REG_SZ, r0					/* skip GBR (used for TLS) */

	lds.l	@r0+, mach					/* load mach/macl registers */
	lds.l	@r0+, macl

	mov	r4, r0						/* bring r0 back to the top of the context */

	mov.l	@(REG_OFFSET(1), r0), r1			/* restore GPRs r1-15 */
	mov.l	@(REG_OFFSET(2), r0), r2
	mov.l	@(REG_OFFSET(3), r0), r3
	mov.l	@(REG_OFFSET(4), r0), r4
	mov.l	@(REG_OFFSET(5), r0), r5
	mov.l	@(REG_OFFSET(6), r0), r6
	mov.l	@(REG_OFFSET(7), r0), r7
	mov.l	@(REG_OFFSET(8), r0), r8
	mov.l	@(REG_OFFSET(9), r0), r9
	mov.l	@(REG_OFFSET(10), r0), r10
	mov.l	@(REG_OFFSET(11), r0), r11
	mov.l	@(REG_OFFSET(12), r0), r12
	mov.l	@(REG_OFFSET(13), r0), r13
	mov.l	@(REG_OFFSET(14), r0), r14
	mov.l	@(REG_OFFSET(15), r0), r15

	mov.l	@(REG_OFFSET(REG_PC), r0), r0
	jmp	@r0
END(libucontext_setcontext)