/*      $NetBSD: mcontext.h,v 1.20 2026/07/10 15:11:25 riastradh Exp $  */

/*-
 * Copyright (c) 1999 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Klaus Klein.
 *
 * 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.
 *
 * 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.
 */

#ifndef _I386_MCONTEXT_H_
#define _I386_MCONTEXT_H_


/*
 * mcontext extensions to handle signal delivery.
 */
#define _UC_SETSTACK    _UC_MD_BIT16
#define _UC_CLRSTACK    _UC_MD_BIT17
#define _UC_VM          _UC_MD_BIT18
#define _UC_TLSBASE     _UC_MD_BIT19
#define _UC_XSAVE       _UC_MD_BIT20

/*
 * Layout of mcontext_t according to the System V Application Binary Interface,
 * Intel386(tm) Architecture Processor Supplement, Fourth Edition.
 */  

/*
 * General register state
 */
#define _NGREG          19
typedef int             __greg_t;
typedef __greg_t        __gregset_t[_NGREG];

#define _REG_GS         0
#define _REG_FS         1
#define _REG_ES         2
#define _REG_DS         3
#define _REG_EDI        4
#define _REG_ESI        5
#define _REG_EBP        6
#define _REG_ESP        7
#define _REG_EBX        8
#define _REG_EDX        9
#define _REG_ECX        10
#define _REG_EAX        11
#define _REG_TRAPNO     12
#define _REG_ERR        13
#define _REG_EIP        14
#define _REG_CS         15
#define _REG_EFL        16
#define _REG_UESP       17
#define _REG_SS         18

/*
 * Floating point register state
 */
typedef struct {
        union {
                struct {
                        int     __fp_state[27]; /* Environment and registers */
                } __fpchip_state;       /* x87 regs in fsave format */
                struct {
                        char    __fp_xmm[512];
                } __fp_xmm_state;       /* x87 and xmm regs in fxsave format */
                int     __fp_fpregs[128];
                struct {
                        /*
                         * `The XSAVE feature set does not use bytes
                         *  511:416; bytes 463:416 are reserved.'
                         *
                         * We take a part out of this to form a pointer
                         * to an external XSAVE area.  This way, we can
                         * replicate the FXSAVE parts for the benefit
                         * of userland programs that aren't aware of
                         * the XSAVE pointer, have used the extended
                         * CPU registers (ymmN/zmmN/&c.), and want to
                         * examine the x87/SSE register state in a
                         * signal handler.  The kernel does not use
                         * this part.
                         */
                        char            __fxsave[416];
                        char            __rsvd[48];
                        __greg_t        __xsaveptr;
                        __greg_t        __xsavelen;
                        char            __pad[40];
                } __xsave;
        } __fp_reg_set;
        int     __fp_pad[33];                   /* Historic padding */
} __fpregset_t;
__CTASSERT(sizeof (__fpregset_t) == 512 + 33 * 4);

typedef struct {
        __gregset_t     __gregs;
        __fpregset_t    __fpregs;
        __greg_t        _mc_tlsbase;
} mcontext_t;

#define _UC_FXSAVE      _UC_MD_BIT5     /* FP state is in FXSAVE format in XMM space */

#define _UC_MACHINE_PAD 4       /* Padding appended to ucontext_t */

#define _UC_UCONTEXT_ALIGN      (~0xf)

#ifndef _UC_MACHINE_SP
#define _UC_MACHINE_SP(uc)      ((uc)->uc_mcontext.__gregs[_REG_UESP])
#endif
#define _UC_MACHINE_FP(uc)      ((uc)->uc_mcontext.__gregs[_REG_EBP])
#define _UC_MACHINE_PC(uc)      ((uc)->uc_mcontext.__gregs[_REG_EIP])
#define _UC_MACHINE_INTRV(uc)   ((uc)->uc_mcontext.__gregs[_REG_EAX])

#define _UC_MACHINE_SET_PC(uc, pc)      _UC_MACHINE_PC(uc) = (pc)

#define __UCONTEXT_SIZE 776

#endif  /* !_I386_MCONTEXT_H_ */