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/*=======================================================================================*/
/* This Sail RISC-V architecture model, comprising all files and */
/* directories except where otherwise noted is subject the BSD */
/* two-clause license in the LICENSE file. */
/* */
/* SPDX-License-Identifier: BSD-2-Clause */
/*=======================================================================================*/
// ****************************************************************
// Parameters for VM modes sv32, sv39, sv48 and (TODO) Sv57
// All VM modes use the same page size (4KB, with 12-bit index)
// This two-line idiom constrains the value (2nd line) to be a singleton,
// which helps in type-checking wherever it is used.
type PAGESIZE_BITS : Int = 12
let pagesize_bits = sizeof(PAGESIZE_BITS)
// PRIVATE
struct SV_Params = {
// VA
va_size_bits : {32, 39, 48}, // 32 39 48
vpn_size_bits : {10, 9}, // 10 9 9
// PTE
levels : { 2, 3, 4}, // 2 3 4
log_pte_size_bytes : { 2, 3}, // 2 3 3
pte_msbs_lsb_index : {32, 54}, // 32 54 54
pte_msbs_size_bits : { 0, 10}, // 0 10 10
pte_PPNs_lsb_index : {10}, // 10 10 10
pte_PPNs_size_bits : {22, 44}, // 22 44 44
pte_PPN_j_size_bits : {10, 9} // 10 9 9
}
// Current level during a page-table walk (0 to SV_Params.levels - 1)
type PTW_Level = range(0,3) // range(0,4) when add Sv57 (TODO)
// PRIVATE
let sv32_params : SV_Params = struct {
// VA
va_size_bits = 32,
vpn_size_bits = 10,
// PTE
levels = 2,
log_pte_size_bytes = 2, // 4 Bytes
pte_msbs_lsb_index = 32,
pte_msbs_size_bits = 0,
pte_PPNs_lsb_index = 10,
pte_PPNs_size_bits = 22,
pte_PPN_j_size_bits = 10
}
// PRIVATE
let sv39_params : SV_Params = struct {
// VA
va_size_bits = 39,
vpn_size_bits = 9,
// PTE
levels = 3,
log_pte_size_bytes = 3, // 8 Bytes
pte_msbs_lsb_index = 54,
pte_msbs_size_bits = 10,
pte_PPNs_lsb_index = 10,
pte_PPNs_size_bits = 44,
pte_PPN_j_size_bits = 9
}
// PRIVATE
let sv48_params : SV_Params = struct {
// VA
va_size_bits = 48,
vpn_size_bits = 9,
// PTE
levels = 4,
log_pte_size_bytes = 3, // 8 Bytes
pte_msbs_lsb_index = 54,
pte_msbs_size_bits = 10,
pte_PPNs_lsb_index = 10,
pte_PPNs_size_bits = 44,
pte_PPN_j_size_bits = 9
}
// TODO; not currently used
// PRIVATE
/*
let sv57_params : SV_Params = struct {
// VA
va_size_bits = 57,
vpn_size_bits = 9,
// PTE
levels = 5,
log_pte_size_bytes = 3, // 8 Bytes
pte_msbs_lsb_index = 54,
pte_msbs_size_bits = 10,
pte_PPNs_lsb_index = 10,
pte_PPNs_size_bits = 44,
pte_PPN_j_size_bits = 9
}
*/
// This 'undefined_SV_Params()' function is not used anywhere, but is
// currently (2023-12) needed to work around an issue where Sail tries
// to figure out how it could do
// let x : SV_Params = undefined
// even though the code never does this. This has been fixed in Sail.
// The fix will become available in a new Sail release, at which point
// this function can be deleted (TODO).
// PRIVATE
val undefined_SV_Params : unit -> SV_Params
function undefined_SV_Params() = sv32_params
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