# SPDX-License-Identifier: GPL-2.0-or-later
# Copyright (C) 2026 Richard Qin

.section .text
.globl trampoline
.globl uservec
.globl userret

.align 12
trampoline:
.align 4
uservec:    
    
    csrrw a0, sscratch, a0

    sd ra, 40(a0)
    sd sp, 48(a0)
    sd gp, 56(a0)
    sd tp, 64(a0)
    sd t0, 72(a0)
    sd t1, 80(a0)
    sd t2, 88(a0)
    sd s0, 96(a0)
    sd s1, 104(a0)
    sd a1, 120(a0)
    sd a2, 128(a0)
    sd a3, 136(a0)
    sd a4, 144(a0)
    sd a5, 152(a0)
    sd a6, 160(a0)
    sd a7, 168(a0)
    sd s2, 176(a0)
    sd s3, 184(a0)
    sd s4, 192(a0)
    sd s5, 200(a0)
    sd s6, 208(a0)
    sd s7, 216(a0)
    sd s8, 224(a0)
    sd s9, 232(a0)
    sd s10, 240(a0)
    sd s11, 248(a0)
    sd t3, 256(a0)
    sd t4, 264(a0)
    sd t5, 272(a0)
    sd t6, 280(a0)

    csrr t0, sscratch
    sd t0, 112(a0)

    ld sp, 8(a0)
    ld tp, 32(a0)
    ld t0, 16(a0)
    ld t1, 0(a0)

    csrw satp, t1
    sfence.vma zero, zero

    jr t0

.align 4
userret:
    
    csrw satp, a1
    sfence.vma zero, zero

    csrw sscratch, a0

    ld ra, 40(a0)
    ld sp, 48(a0)
    ld gp, 56(a0)
    ld tp, 64(a0)
    ld t0, 72(a0)
    ld t1, 80(a0)
    ld t2, 88(a0)
    ld s0, 96(a0)
    ld s1, 104(a0)
    ld a1, 120(a0)
    ld a2, 128(a0)
    ld a3, 136(a0)
    ld a4, 144(a0)
    ld a5, 152(a0)
    ld a6, 160(a0)
    ld a7, 168(a0)
    ld s2, 176(a0)
    ld s3, 184(a0)
    ld s4, 192(a0)
    ld s5, 200(a0)
    ld s6, 208(a0)
    ld s7, 216(a0)
    ld s8, 224(a0)
    ld s9, 232(a0)
    ld s10, 240(a0)
    ld s11, 248(a0)
    ld t3, 256(a0)
    ld t4, 264(a0)
    ld t5, 272(a0)
    ld t6, 280(a0)
    
    ld a0, 112(a0)
    
    sret