1# Copyright (c) 2007-2008 The Hewlett-Packard Development Company 2# All rights reserved. 3# 4# Redistribution and use of this software in source and binary forms, 5# with or without modification, are permitted provided that the 6# following conditions are met: 7# 8# The software must be used only for Non-Commercial Use which means any 9# use which is NOT directed to receiving any direct monetary 10# compensation for, or commercial advantage from such use. Illustrative 11# examples of non-commercial use are academic research, personal study, 12# teaching, education and corporate research & development. 13# Illustrative examples of commercial use are distributing products for 14# commercial advantage and providing services using the software for 15# commercial advantage. 16# 17# If you wish to use this software or functionality therein that may be 18# covered by patents for commercial use, please contact: 19# Director of Intellectual Property Licensing 20# Office of Strategy and Technology 21# Hewlett-Packard Company 22# 1501 Page Mill Road 23# Palo Alto, California 94304 24# 25# Redistributions of source code must retain the above copyright notice, 26# this list of conditions and the following disclaimer. Redistributions 27# in binary form must reproduce the above copyright notice, this list of 28# conditions and the following disclaimer in the documentation and/or 29# other materials provided with the distribution. Neither the name of 30# the COPYRIGHT HOLDER(s), HEWLETT-PACKARD COMPANY, nor the names of its 31# contributors may be used to endorse or promote products derived from 32# this software without specific prior written permission. No right of 33# sublicense is granted herewith. Derivatives of the software and 34# output created using the software may be prepared, but only for 35# Non-Commercial Uses. Derivatives of the software may be shared with 36# others provided: (i) the others agree to abide by the list of 37# conditions herein which includes the Non-Commercial Use restrictions; 38# and (ii) such Derivatives of the software include the above copyright 39# notice to acknowledge the contribution from this software where 40# applicable, this list of conditions and the disclaimer below. 41# 42# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 43# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 44# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 45# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 46# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 47# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 48# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 49# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 50# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 51# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 52# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 53# 54# Authors: Gabe Black 55 56microcode = ''' 57def macroop IRET_REAL { 58 panic "Real mode iret isn't implemented!" 59}; 60 61def macroop IRET_PROT { 62 .adjust_env oszIn64Override 63 64 # Check for a nested task. This isn't supported at the moment. 65 rflag t1, NT 66 panic "Task switching with iret is unimplemented!", flags=(nCEZF,) 67 68 #t1 = temp_RIP 69 #t2 = temp_CS 70 #t3 = temp_RFLAGS 71 #t4 = handy m5 register 72 73 # Pop temp_RIP, temp_CS, and temp_RFLAGS 74 ld t1, ss, [1, t0, rsp], "0 * env.stackSize", dataSize=ssz 75 ld t2, ss, [1, t0, rsp], "1 * env.stackSize", dataSize=ssz 76 ld t3, ss, [1, t0, rsp], "2 * env.stackSize", dataSize=ssz 77 78 # Read the handy m5 register for use later 79 rdm5reg t4 80 81 82### 83### Handle if we're returning to virtual 8086 mode. 84### 85 86 #IF ((temp_RFLAGS.VM=1) && (CPL=0) && (LEGACY_MODE)) 87 # IRET_FROM_PROTECTED_TO_VIRTUAL 88 89 #temp_RFLAGS.VM != 1 90 rcri t0, t3, 18, flags=(ECF,) 91 br label("protToVirtFallThrough"), flags=(nCECF,) 92 93 #CPL=0 94 andi t0, t4, 0x30, flags=(EZF,) 95 br label("protToVirtFallThrough"), flags=(nCEZF,) 96 97 #(LEGACY_MODE) 98 rcri t0, t4, 1, flags=(ECF,) 99 br label("protToVirtFallThrough"), flags=(nCECF,) 100 101 panic "iret to virtual mode not supported" 102 103protToVirtFallThrough: 104 105 106 107 #temp_CPL = temp_CS.rpl 108 andi t5, t2, 0x3 109 110 111### 112### Read in the info for the new CS segment. 113### 114 115 #CS = READ_DESCRIPTOR (temp_CS, iret_chk) 116 andi t0, t2, 0xFC, flags=(EZF,), dataSize=2 117 br label("processCSDescriptor"), flags=(CEZF,) 118 andi t6, t2, 0xF8, dataSize=8 119 andi t0, t2, 0x4, flags=(EZF,), dataSize=2 120 br label("globalCSDescriptor"), flags=(CEZF,) 121 ld t8, tsl, [1, t0, t6], dataSize=8 122 br label("processCSDescriptor") 123globalCSDescriptor: 124 ld t8, tsg, [1, t0, t6], dataSize=8 125processCSDescriptor: 126 chks t2, t6, dataSize=8 127 128 129### 130### Get the new stack pointer and stack segment off the old stack if necessary, 131### and piggyback on the logic to check the new RIP value. 132### 133 #IF ((64BIT_MODE) || (temp_CPL!=CPL)) 134 #{ 135 136 #(64BIT_MODE) 137 andi t0, t4, 0xE, flags=(EZF,) 138 # Since we just found out we're in 64 bit mode, take advantage and 139 # do the appropriate RIP checks. 140 br label("doPopStackStuffAndCheckRIP"), flags=(CEZF,) 141 142 # Here, we know we're -not- in 64 bit mode, so we should do the 143 # appropriate/other RIP checks. 144 # if temp_RIP > CS.limit throw #GP(0) 145 rdlimit t6, cs, dataSize=8
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147 fault "new GeneralProtection(0)", flags=(CECF,) 148 149 #(temp_CPL!=CPL) 150 srli t7, t4, 4 151 xor t7, t7, t5 152 andi t0, t7, 0x3, flags=(EZF,) 153 br label("doPopStackStuff"), flags=(nCEZF,) 154 # We can modify user visible state here because we're know 155 # we're done with things that can fault. 156 addi rsp, rsp, "3 * env.stackSize" 157 br label("fallThroughPopStackStuff") 158 159doPopStackStuffAndCheckRIP: 160 # Check if the RIP is canonical. 161 srai t7, t1, 47, flags=(EZF,), dataSize=ssz 162 # if t7 isn't 0 or -1, it wasn't canonical. 163 br label("doPopStackStuff"), flags=(CEZF,) 164 addi t0, t7, 1, flags=(EZF,), dataSize=ssz 165 fault "new GeneralProtection(0)", flags=(nCEZF,) 166 167doPopStackStuff: 168 # POP.v temp_RSP 169 ld t6, ss, [1, t0, rsp], "3 * env.dataSize", dataSize=ssz 170 # POP.v temp_SS 171 ld t9, ss, [1, t0, rsp], "4 * env.dataSize", dataSize=ssz 172 # SS = READ_DESCRIPTOR (temp_SS, ss_chk) 173 andi t0, t9, 0xFC, flags=(EZF,), dataSize=2 174 br label("processSSDescriptor"), flags=(CEZF,) 175 andi t7, t9, 0xF8, dataSize=8 176 andi t0, t9, 0x4, flags=(EZF,), dataSize=2 177 br label("globalSSDescriptor"), flags=(CEZF,) 178 ld t7, tsl, [1, t0, t7], dataSize=8 179 br label("processSSDescriptor") 180globalSSDescriptor: 181 ld t7, tsg, [1, t0, t7], dataSize=8 182processSSDescriptor: 183 chks t9, t7, dataSize=8 184 185 # This actually updates state which is wrong. It should wait until we know 186 # we're not going to fault. Unfortunately, that's hard to do. 187 wrdl ss, t7, t9 188 wrsel ss, t9 189 190### 191### From this point downwards, we can't fault. We can update user visible state. 192### 193 # RSP.s = temp_RSP 194 mov rsp, rsp, t6, dataSize=ssz 195 196 #} 197 198fallThroughPopStackStuff: 199 200 # Update CS 201 wrdl cs, t8, t2 202 wrsel cs, t2 203 204 #CPL = temp_CPL 205 206 #IF (changing CPL) 207 #{ 208 srli t7, t4, 4 209 xor t7, t7, t5 210 andi t0, t7, 0x3, flags=(EZF,) 211 br label("skipSegmentSquashing"), flags=(CEZF,) 212 213 # The attribute register needs to keep track of more info before this will 214 # work the way it needs to. 215 # FOR (seg = ES, DS, FS, GS) 216 # IF ((seg.attr.dpl < cpl && ((seg.attr.type = 'data') 217 # || (seg.attr.type = 'non-conforming-code'))) 218 # { 219 # seg = NULL 220 # } 221 #} 222 223skipSegmentSquashing: 224 225 # Ignore this for now. 226 #RFLAGS.v = temp_RFLAGS 227 wrflags t0, t3 228 # VIF,VIP,IOPL only changed if (old_CPL = 0) 229 # IF only changed if (old_CPL <= old_RFLAGS.IOPL) 230 # VM unchanged 231 # RF cleared 232 233 #RIP = temp_RIP 234 wrip t0, t1, dataSize=ssz 235}; 236 237def macroop IRET_VIRT { 238 panic "Virtual mode iret isn't implemented!" 239}; 240''' 241#let {{ 242# class INT(Inst): 243# "GenFault ${new UnimpInstFault}" 244# class INTO(Inst): 245# "GenFault ${new UnimpInstFault}" 246#}};
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