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Toooba/src_Testbench/SoC/Boot_ROM.bsv
2020-07-06 17:39:25 +01:00

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// Copyright (c) 2016-2019 Bluespec, Inc. All Rights Reserved
//
//-
// RVFI_DII + CHERI modifications:
// Copyright (c) 2020 Alexandre Joannou
// All rights reserved.
//
// This software was developed by SRI International and the University of
// Cambridge Computer Laboratory (Department of Computer Science and
// Technology) under DARPA contract HR0011-18-C-0016 ("ECATS"), as part of the
// DARPA SSITH research programme.
//
// This work was supported by NCSC programme grant 4212611/RFA 15971 ("SafeBet").
//-
package Boot_ROM;
// ================================================================
// This package implements a slave IP that is a RISC-V boot ROM of
// 1024 32b locations.
// - Ignores all writes, always responsing OKAY
// - Assumes all reads are 4-byte aligned requests for 4-bytes
// ================================================================
export Boot_ROM_IFC (..), mkBoot_ROM;
// ================================================================
// BSV library imports
import ConfigReg :: *;
// ----------------
// BSV additional libs
import Cur_Cycle :: *;
import GetPut_Aux :: *;
import Semi_FIFOF :: *;
import AXI4 :: *;
import SourceSink :: *;
// ================================================================
// Project imports
import Fabric_Defs :: *;
import SoC_Map :: *;
// ================================================================
// Include the auto-generated BSV-include file with the ROM function
`ifdef RV32
`include "fn_read_ROM_RV32.bsvi"
`endif
`ifdef RV64
`include "fn_read_ROM_RV64.bsvi"
`endif
// ================================================================
// Interface
interface Boot_ROM_IFC;
// set_addr_map should be called after this module's reset
method Action set_addr_map (Fabric_Addr addr_base, Fabric_Addr addr_lim);
// Main Fabric Reqs/Rsps
interface AXI4_Slave_Synth #(Wd_SId, Wd_Addr, Wd_Data,
Wd_AW_User, Wd_W_User, Wd_B_User,
Wd_AR_User, Wd_R_User) slave;
endinterface
// ================================================================
(* synthesize *)
module mkBoot_ROM (Boot_ROM_IFC);
// Verbosity: 0: quiet; 1: reads/writes
Integer verbosity = 0;
Reg #(Bool) rg_module_ready <- mkReg (False);
Reg #(Fabric_Addr) rg_addr_base <- mkRegU;
Reg #(Fabric_Addr) rg_addr_lim <- mkRegU;
// ----------------
// Connector to fabric
AXI4_Slave_Width_Xactor#(Wd_SId, Wd_Addr, Wd_Data_Periph, Wd_Data,
Wd_AW_User_Periph, Wd_W_User_Periph, Wd_B_User_Periph, Wd_AR_User_Periph, Wd_R_User_Periph,
Wd_AW_User, Wd_W_User, Wd_B_User, Wd_AR_User, Wd_R_User) slave_xactor <- mkAXI4_Slave_Zeroing_Xactor;
// ----------------
function Bool fn_addr_is_aligned (Fabric_Addr addr);
if (valueOf (Wd_Data) == 32)
return (addr [1:0] == 2'b_00);
else if (valueOf (Wd_Data) == 64)
return (addr [2:0] == 3'b_000);
else
return False;
endfunction
function Bool fn_addr_is_in_range (Fabric_Addr base, Fabric_Addr addr, Fabric_Addr lim);
return ((base <= addr) && (addr < lim));
endfunction
function Bool fn_addr_is_ok (Fabric_Addr base, Fabric_Addr addr, Fabric_Addr lim);
return ( fn_addr_is_aligned (addr)
&& fn_addr_is_in_range (base, addr, lim));
endfunction
// ================================================================
// BEHAVIOR
// ----------------------------------------------------------------
// Handle fabric read requests
rule rl_process_rd_req (rg_module_ready);
let rda <- get(slave_xactor.master.ar);
let byte_addr = rda.araddr - rg_addr_base;
AXI4_Resp rresp = OKAY;
Bit #(64) data64 = 0;
if (! fn_addr_is_ok (rg_addr_base, rda.araddr, rg_addr_lim)) begin
rresp = SLVERR;
$display ("%0d: ERROR: Boot_ROM.rl_process_rd_req: unrecognized addr", cur_cycle);
$display (" ", fshow (rda));
end
else if (rda.araddr [2:0] == 3'b0) begin
Bit #(32) d0 = fn_read_ROM_0 (byte_addr);
Bit #(32) d1 = fn_read_ROM_4 (byte_addr + 4);
data64 = { d1, d0 };
end
else begin // ((valueOf (Wd_Data) == 32) && (rda.addr [1:0] == 2'b_00))
Bit #(32) d1 = fn_read_ROM_4 (byte_addr);
data64 = { 0, d1 };
end
Bit #(Wd_Data) rdata = truncate (data64);
let rdr = AXI4_RFlit {rid: rda.arid,
rdata: rdata,
rresp: rresp,
rlast: True,
ruser: rda.aruser}; // XXX This requires that Wd_AR_User == Wd_R_User
slave_xactor.master.r.put(rdr);
if (verbosity > 0) begin
$display ("%0d: Boot_ROM.rl_process_rd_req: ", cur_cycle);
$display (" ", fshow (rda));
$display (" => ", fshow (rdr));
end
endrule
// ----------------------------------------------------------------
// Handle fabric write requests: ignore all of them (this is a ROM)
rule rl_process_wr_req (rg_module_ready);
let wra <- get(slave_xactor.master.aw);
let wrd <- get(slave_xactor.master.w);
AXI4_Resp bresp = OKAY;
if (! fn_addr_is_ok (rg_addr_base, wra.awaddr, rg_addr_lim)) begin
bresp = SLVERR;
$display ("%0d: ERROR: Boot_ROM.rl_process_wr_req: unrecognized addr", cur_cycle);
$display (" ", fshow (wra));
end
let wrr = AXI4_BFlit {bid: wra.awid,
bresp: bresp,
buser: wra.awuser}; // XXX This requires that Wd_AW_User == Wd_B_User
slave_xactor.master.b.put(wrr);
if (verbosity > 0) begin
$display ("%0d: Boot_ROM.rl_process_wr_req; ignoring all writes", cur_cycle);
$display (" ", fshow (wra));
$display (" ", fshow (wrd));
$display (" => ", fshow (wrr));
end
endrule
// ================================================================
// INTERFACE
// set_addr_map should be called after this module's reset
method Action set_addr_map (Fabric_Addr addr_base, Fabric_Addr addr_lim);
if (valueOf (Wd_Data) == 32) begin
if (addr_base [1:0] != 0)
$display ("%0d: WARNING: Boot_ROM.set_addr_map: addr_base 0x%0h is not 4-Byte-aligned",
cur_cycle, addr_base);
if (addr_lim [1:0] != 0)
$display ("%0d: WARNING: Boot_ROM.set_addr_map: addr_lim 0x%0h is not 4-Byte-aligned",
cur_cycle, addr_lim);
end
else if (valueOf (Wd_Data) == 64) begin
if (addr_base [2:0] != 0)
$display ("%0d: WARNING: Boot_ROM.set_addr_map: addr_base 0x%0h is not 4-Byte-aligned",
cur_cycle, addr_base);
if (addr_lim [2:0] != 0)
$display ("%0d: WARNING: Boot_ROM.set_addr_map: addr_lim 0x%0h is not 4-Byte-aligned",
cur_cycle, addr_lim);
end
rg_addr_base <= addr_base;
rg_addr_lim <= addr_lim;
rg_module_ready <= True;
slave_xactor.clear;
if (verbosity > 0) begin
$display ("%0d: Boot_ROM.set_addr_map: base 0x%0h lim 0x%0h", cur_cycle, addr_base, addr_lim);
end
endmethod
// Main Fabric Reqs/Rsps
interface slave = slave_xactor.slaveSynth;
endmodule
// ================================================================
endpackage