///////////////////////////////////////////
// tlbGP.S
//
// Written: mmendozamanriquez@hmc.edu 4 April 2023
//          nlimpert@hmc.edu
//
// Purpose: Create Page tables and access gigapages
//
// A component of the CORE-V-WALLY configurable RISC-V project.
// https://github.com/openhwgroup/cvw
// 
// Copyright (C) 2021-23 Harvey Mudd College & Oklahoma State University
//
// SPDX-License-Identifier: Apache-2.0 WITH SHL-2.1
//
// Licensed under the Solderpad Hardware License v 2.1 (the “License”); you may not use this file 
// except in compliance with the License, or, at your option, the Apache License version 2.0. You 
// may obtain a copy of the License at
//
// https://solderpad.org/licenses/SHL-2.1/
//
// Unless required by applicable law or agreed to in writing, any work distributed under the 
// License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, 
// either express or implied. See the License for the specific language governing permissions 
// and limitations under the License.
////////////////////////////////////////////////////////////////////////////////////////////////

// load code to initalize stack, handle interrupts, terminate

#include "WALLY-init-lib.h"

# run-elf.bash find this in project description
main:
    # Page table root address at 0x80010000
    li t5, 0x9000000000080010
    csrw satp, t5

    # sfence.vma x0, x0

    # switch to supervisor mode
    li a0, 1   
    ecall
    li t5, 0 
    li t0, 0xC0200000 // go to first gigapage 
    li t4, 0x40000000 // put this outside the loop.
    li t2, 0      # i = 0
    li t3, 64     # Max amount of Loops = 16

loop: bge t2, t3, finished   # exit loop if i >= loops
    lw t1, 0(t0)
    li t1, 0x00008067 #load in jalr
    sw t1, 0(t0)
    fence.I
    jalr t0
    add t0, t0, t4
    addi t2, t2, 1
    j loop

finished:
    j done

.data

.align 16
# Page table situated at 0x80010000
pagetable: 
    .8byte 0x200044C1

.align 12 
    .8byte 0x000000CF  //8000 0000
    .8byte 0x100000CF
    .8byte 0x200000CF  
    .8byte 0x200000CF  

    .8byte 0x200000CF
    .8byte 0x200000CF
    .8byte 0x200000CF
    .8byte 0x200000CF  
 
    .8byte 0x200000CF
    .8byte 0x200000CF 
    .8byte 0x200000CF
    .8byte 0x200000CF  

    .8byte 0x200000CF
    .8byte 0x200000CF
    .8byte 0x200000CF 
    .8byte 0x200000CF  

    .8byte 0x200000CF  
    .8byte 0x200000CF
    .8byte 0x200000CF  
    .8byte 0x200000CF  

    .8byte 0x200000CF
    .8byte 0x200000CF
    .8byte 0x200000CF
    .8byte 0x200000CF  
 
    .8byte 0x200000CF
    .8byte 0x200000CF 
    .8byte 0x200000CF
    .8byte 0x200000CF  

    .8byte 0x200000CF
    .8byte 0x200000CF
    .8byte 0x200000CF 
    .8byte 0x200000CF  

    .8byte 0x200000CF  
    .8byte 0x200000CF
    .8byte 0x200000CF  
    .8byte 0x200000CF  

    .8byte 0x200000CF
    .8byte 0x200000CF
    .8byte 0x200000CF
    .8byte 0x200000CF  
 
    .8byte 0x200000CF
    .8byte 0x200000CF 
    .8byte 0x200000CF
    .8byte 0x200000CF  

    .8byte 0x200000CF
    .8byte 0x200000CF
    .8byte 0x200000CF 
    .8byte 0x200000CF  

    .8byte 0x200000CF  
    .8byte 0x200000CF
    .8byte 0x200000CF  
    .8byte 0x200000CF  

    .8byte 0x200000CF
    .8byte 0x200000CF
    .8byte 0x200000CF
    .8byte 0x200000CF  
 
    .8byte 0x200000CF
    .8byte 0x200000CF 
    .8byte 0x200000CF
    .8byte 0x200000CF  

    .8byte 0x200000CF
    .8byte 0x200000CF
    .8byte 0x200000CF 
    .8byte 0x200000CF  


    .8byte 0x200000CF
    .8byte 0x200000CF
    .8byte 0x200000CF 
    .8byte 0x200000CF