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// See LICENSE for license details.
#include "encoding.h"
#include "bits.h"
.macro save_tf
# save gprs
STORE x1,1*REGBYTES(x2)
STORE x3,3*REGBYTES(x2)
STORE x4,4*REGBYTES(x2)
STORE x5,5*REGBYTES(x2)
STORE x6,6*REGBYTES(x2)
STORE x7,7*REGBYTES(x2)
STORE x8,8*REGBYTES(x2)
STORE x9,9*REGBYTES(x2)
STORE x10,10*REGBYTES(x2)
STORE x11,11*REGBYTES(x2)
STORE x12,12*REGBYTES(x2)
STORE x13,13*REGBYTES(x2)
STORE x14,14*REGBYTES(x2)
STORE x15,15*REGBYTES(x2)
STORE x16,16*REGBYTES(x2)
STORE x17,17*REGBYTES(x2)
STORE x18,18*REGBYTES(x2)
STORE x19,19*REGBYTES(x2)
STORE x20,20*REGBYTES(x2)
STORE x21,21*REGBYTES(x2)
STORE x22,22*REGBYTES(x2)
STORE x23,23*REGBYTES(x2)
STORE x24,24*REGBYTES(x2)
STORE x25,25*REGBYTES(x2)
STORE x26,26*REGBYTES(x2)
STORE x27,27*REGBYTES(x2)
STORE x28,28*REGBYTES(x2)
STORE x29,29*REGBYTES(x2)
STORE x30,30*REGBYTES(x2)
STORE x31,31*REGBYTES(x2)
# get sr, epc, badvaddr, cause
csrrw t0,sscratch,x0
csrr s0,sstatus
csrr t1,sepc
csrr t2,sbadaddr
csrr t3,scause
STORE t0,2*REGBYTES(x2)
STORE s0,32*REGBYTES(x2)
STORE t1,33*REGBYTES(x2)
STORE t2,34*REGBYTES(x2)
STORE t3,35*REGBYTES(x2)
# get faulting insn, if it wasn't a fetch-related trap
li x5,-1
STORE x5,36*REGBYTES(x2)
1:
.endm
.text
.align 2
.global trap_entry
trap_entry:
csrrw sp, sscratch, sp
bnez sp, 1f
csrr sp, sscratch
1:addi sp,sp,-320
save_tf
move a0,sp
jal handle_trap
mv a0,sp
# don't restore sscratch if trap came from kernel
andi s0,s0,SSTATUS_SPP
bnez s0,start_user
addi sp,sp,320
csrw sscratch,sp
.globl start_user
start_user:
LOAD t0, 32*REGBYTES(a0)
LOAD t1, 33*REGBYTES(a0)
csrw sstatus, t0
csrw sepc, t1
# restore x registers
LOAD x1,1*REGBYTES(a0)
LOAD x2,2*REGBYTES(a0)
LOAD x3,3*REGBYTES(a0)
LOAD x4,4*REGBYTES(a0)
LOAD x5,5*REGBYTES(a0)
LOAD x6,6*REGBYTES(a0)
LOAD x7,7*REGBYTES(a0)
LOAD x8,8*REGBYTES(a0)
LOAD x9,9*REGBYTES(a0)
LOAD x11,11*REGBYTES(a0)
LOAD x12,12*REGBYTES(a0)
LOAD x13,13*REGBYTES(a0)
LOAD x14,14*REGBYTES(a0)
LOAD x15,15*REGBYTES(a0)
LOAD x16,16*REGBYTES(a0)
LOAD x17,17*REGBYTES(a0)
LOAD x18,18*REGBYTES(a0)
LOAD x19,19*REGBYTES(a0)
LOAD x20,20*REGBYTES(a0)
LOAD x21,21*REGBYTES(a0)
LOAD x22,22*REGBYTES(a0)
LOAD x23,23*REGBYTES(a0)
LOAD x24,24*REGBYTES(a0)
LOAD x25,25*REGBYTES(a0)
LOAD x26,26*REGBYTES(a0)
LOAD x27,27*REGBYTES(a0)
LOAD x28,28*REGBYTES(a0)
LOAD x29,29*REGBYTES(a0)
LOAD x30,30*REGBYTES(a0)
LOAD x31,31*REGBYTES(a0)
# restore a0 last
LOAD x10,10*REGBYTES(a0)
# gtfo
sret
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