| Line 4... |
Line 4... |
-- project: ION (http://www.opencores.org/project,ion_cpu)
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-- project: ION (http://www.opencores.org/project,ion_cpu)
|
-- author: Jose A. Ruiz (ja_rd@hotmail.com)
|
-- author: Jose A. Ruiz (ja_rd@hotmail.com)
|
-- created: Jan/11/2011
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-- created: Jan/11/2011
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-- last modified: Jun/05/2011 (ja_rd@hotmail.com)
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-- last modified: Jun/05/2011 (ja_rd@hotmail.com)
|
--------------------------------------------------------------------------------
|
--------------------------------------------------------------------------------
|
-- Use under the terms of the GPL.
|
|
-- Software 'as is' without warranty. Author liable for nothing.
|
|
--
|
|
--------------------------------------------------------------------------------
|
|
-- Please read file /doc/ion_project.txt for usage instructions.
|
-- Please read file /doc/ion_project.txt for usage instructions.
|
--------------------------------------------------------------------------------
|
--------------------------------------------------------------------------------
|
--### MIPS-I things not implemented
|
--### MIPS-I things not implemented
|
--
|
--
|
-- 1.- Most of the R3000 CP0 registers and of course all of the CP1.
|
-- 1.- Most of the R3000 CP0 registers and of course all of the CP1.
|
| Line 35... |
Line 31... |
-- Besides, see point 2 above about the missing SR bits.
|
-- Besides, see point 2 above about the missing SR bits.
|
--
|
--
|
--------------------------------------------------------------------------------
|
--------------------------------------------------------------------------------
|
-- KNOWN BUGS:
|
-- KNOWN BUGS:
|
--
|
--
|
-- 1.- The instruction after entering user mode (i.e. the instruction after the
|
-- 1.- The instruction executed right after entering user mode (i.e. the
|
-- MTC0 or RFE that clears the KU flag) is executed in kernel mode.
|
-- instruction after the MTC0 or RFE that clears the KU flag) is executed
|
|
-- in kernel mode (instead of user mode). This is a gapping security hole,
|
|
-- in case it makes any sense to speak of security in this project at this
|
|
-- stage.
|
-- This can be easily fixed but is not very urgent.
|
-- This can be easily fixed but is not very urgent.
|
--------------------------------------------------------------------------------
|
--------------------------------------------------------------------------------
|
|
-- Copyright (C) 2010 Jose A. Ruiz
|
|
--
|
|
-- This source file may be used and distributed without
|
|
-- restriction provided that this copyright statement is not
|
|
-- removed from the file and that any derivative work contains
|
|
-- the original copyright notice and the associated disclaimer.
|
|
--
|
|
-- This source file is free software; you can redistribute it
|
|
-- and/or modify it under the terms of the GNU Lesser General
|
|
-- Public License as published by the Free Software Foundation;
|
|
-- either version 2.1 of the License, or (at your option) any
|
|
-- later version.
|
|
--
|
|
-- This source is distributed in the hope that it will be
|
|
-- useful, but WITHOUT ANY WARRANTY; without even the implied
|
|
-- warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
|
|
-- PURPOSE. See the GNU Lesser General Public License for more
|
|
-- details.
|
|
--
|
|
-- You should have received a copy of the GNU Lesser General
|
|
-- Public License along with this source; if not, download it
|
|
-- from http://www.opencores.org/lgpl.shtml
|
|
--------------------------------------------------------------------------------
|
|
|
library ieee;
|
library ieee;
|
use ieee.std_logic_1164.all;
|
use ieee.std_logic_1164.all;
|
use ieee.std_logic_arith.all;
|
use ieee.std_logic_arith.all;
|
use ieee.std_logic_unsigned.all;
|
use ieee.std_logic_unsigned.all;
|
