/* $NetBSD: reg.h,v 1.10 2022/12/13 22:25:08 skrll Exp $ */

/*-
* Copyright (c) 2014 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Matt Thomas of 3am Software Foundry.
*
* 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 _RISCV_REG_H_
#define _RISCV_REG_H_

// x0           = 0
// x1           = ra            (return address)                  Caller
// x2           = sp            (stack pointer)                   Callee
// x3           = gp            (global pointer)
// x4           = tp            (thread pointer)
// x5 - x7      = t0 - t2       (temporary)                       Caller
// x8           = s0/fp         (saved register / frame pointer)  Callee
// x9           = s1            (saved register)                  Callee
// x10 - x11    = a0 - a1       (arguments/return values)         Caller
// x12 - x17    = a2 - a7       (arguments)                       Caller
// x18 - x27    = s2 - s11      (saved registers)                 Callee
// x28 - x31    = t3 - t6       (temporaries)                     Caller

struct reg {    // synced with register_t in <riscv/types.h>
#ifdef _LP64
       __uint64_t r_reg[31]; /* x0 is always 0 */
       __uint64_t r_pc;
#else
       __uint32_t r_reg[31]; /* x0 is always 0 */
       __uint32_t r_pc;
#endif
};

#ifdef _LP64
struct reg32 {  // synced with register_t in <riscv/types.h>
       __uint32_t r_reg[31]; /* x0 is always 0 */
       __uint32_t r_pc;
};
#endif

#define _XREG(n)        ((n) - 1)
#define _X_RA           _XREG(1)
#define _X_SP           _XREG(2)
#define _X_GP           _XREG(3)
#define _X_TP           _XREG(4)
#define _X_T0           _XREG(5)
#define _X_T1           _XREG(6)
#define _X_T2           _XREG(7)
#define _X_S0           _XREG(8)
#define _X_S1           _XREG(9)
#define _X_A0           _XREG(10)
#define _X_A1           _XREG(11)
#define _X_A2           _XREG(12)
#define _X_A3           _XREG(13)
#define _X_A4           _XREG(14)
#define _X_A5           _XREG(15)
#define _X_A6           _XREG(16)
#define _X_A7           _XREG(17)
#define _X_S2           _XREG(18)
#define _X_S3           _XREG(19)
#define _X_S4           _XREG(20)
#define _X_S5           _XREG(21)
#define _X_S6           _XREG(22)
#define _X_S7           _XREG(23)
#define _X_S8           _XREG(24)
#define _X_S9           _XREG(25)
#define _X_S10          _XREG(26)
#define _X_S11          _XREG(27)
#define _X_T3           _XREG(28)
#define _X_T4           _XREG(29)
#define _X_T5           _XREG(30)
#define _X_T6           _XREG(31)

// f0 - f7      = ft0 - ft7     (FP temporaries)                  Caller
// following layout is similar to integer registers above
// f8 - f9      = fs0 - fs1     (FP saved registers)              Callee
// f10 - f11    = fa0 - fa1     (FP arguments/return values)      Caller
// f12 - f17    = fa2 - fa7     (FP arguments)                    Caller
// f18 - f27    = fs2 - fa11    (FP saved registers)              Callee
// f28 - f31    = ft8 - ft11    (FP temporaries)                  Caller

/*
* This fragment is common to <riscv/mcontext.h> and <riscv/reg.h>
*/
#ifndef _BSD_FPREG_T_
union __fpreg {
       __uint64_t u_u64;
       double u_d;
};
#define _BSD_FPREG_T_   union __fpreg
#endif

/*
* 32 double precision floating point, 1 CSR
*/
struct fpreg {
       _BSD_FPREG_T_   r_fpreg[33];
};
#define r_fcsr          r_fpreg[32].u_u64

#endif /* _RISCV_REG_H_ */