libucontext/arch/riscv64/swapcontext.S

81 lines
2.1 KiB
ArmAsm

/*
* 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(swapcontext, __swapcontext)
FUNC(__swapcontext)
/* move $a1 to $t0 to avoid clobbering. */
mv t0, a1
sd ra, PC_OFFSET(a0)
sd ra, REG_OFFSET(REG_PC)(a0)
sd sp, REG_OFFSET(REG_SP)(a0)
/* first saved register block */
sd s0, REG_OFFSET(REG_S0)(a0)
sd s1, REG_OFFSET(REG_S1)(a0)
/* return register block */
sd a0, REG_OFFSET(REG_A0)(a0)
sd a1, REG_OFFSET(REG_A1)(a0)
/* second saved register block */
sd s2, REG_OFFSET(REG_S2)(a0)
sd s3, REG_OFFSET(REG_S3)(a0)
sd s4, REG_OFFSET(REG_S4)(a0)
sd s5, REG_OFFSET(REG_S5)(a0)
sd s6, REG_OFFSET(REG_S6)(a0)
sd s7, REG_OFFSET(REG_S7)(a0)
sd s8, REG_OFFSET(REG_S8)(a0)
sd s9, REG_OFFSET(REG_S9)(a0)
sd s10, REG_OFFSET(REG_S10)(a0)
sd s11, REG_OFFSET(REG_S11)(a0)
/* restore the other context from $t0. */
ld t1, PC_OFFSET(t0)
ld ra, REG_OFFSET(REG_PC)(t0)
ld sp, REG_OFFSET(REG_SP)(t0)
/* first saved register block */
ld s0, REG_OFFSET(REG_S0)(t0)
ld s1, REG_OFFSET(REG_S1)(t0)
/* return register block */
ld a0, REG_OFFSET(REG_A0)(t0)
ld a1, REG_OFFSET(REG_A1)(t0)
/* argument register block */
ld a2, REG_OFFSET(REG_A2)(t0)
ld a3, REG_OFFSET(REG_A3)(t0)
ld a4, REG_OFFSET(REG_A4)(t0)
ld a5, REG_OFFSET(REG_A5)(t0)
ld a6, REG_OFFSET(REG_A6)(t0)
ld a7, REG_OFFSET(REG_A7)(t0)
/* second saved register block */
ld s2, REG_OFFSET(REG_S2)(t0)
ld s3, REG_OFFSET(REG_S3)(t0)
ld s4, REG_OFFSET(REG_S4)(t0)
ld s5, REG_OFFSET(REG_S5)(t0)
ld s6, REG_OFFSET(REG_S6)(t0)
ld s7, REG_OFFSET(REG_S7)(t0)
ld s8, REG_OFFSET(REG_S8)(t0)
ld s9, REG_OFFSET(REG_S9)(t0)
ld s10, REG_OFFSET(REG_S10)(t0)
ld s11, REG_OFFSET(REG_S11)(t0)
/* done swapping, return */
ret
END(__swapcontext)