interrupts_and_exceptions.py (5081:2ccce8600a9d) interrupts_and_exceptions.py (5434:2f6dad874e14)
1# Copyright (c) 2007 The Hewlett-Packard Development Company
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

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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
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

--- 38 unchanged lines hidden (view full) ---

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 = ""
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
79
80###
81### Handle if we're returning to virtual 8086 mode.
82###
83
84 #IF ((temp_RFLAGS.VM=1) && (CPL=0) && (LEGACY_MODE))
85 # IRET_FROM_PROTECTED_TO_VIRTUAL
86
87 #temp_RFLAGS.VM != 1
88 rcri t0, t3, 18, flags=(ECF,)
89 bri t0, label("protToVirtFallThrough"), flags=(nCECF,)
90
91 #CPL=0
92 rdm5reg t4
93 andi t0, t4, 0x30, flags=(EZF,)
94 bri t0, label("protToVirtFallThrough"), flags=(nCEZF,)
95
96 #(LEGACY_MODE)
97 rcri t0, t4, 1, flags=(ECF,)
98 bri t0, label("protToVirtFallThrough"), flags=(nCECF,)
99
100 panic "iret to virtual mode not supported"
101
102protToVirtFallThrough:
103
104
105
106 #temp_CPL = temp_CS.rpl
107 andi t5, t2, 0x3
108
109
110###
111### Read in the info for the new CS segment.
112###
113
114 #CS = READ_DESCRIPTOR (temp_CS, iret_chk)
115 andi t0, t2, 0xFC, flags=(EZF,), dataSize=2
116 bri t0, label("processCSDescriptor"), flags=(CEZF,)
117 andi t6, t2, 0xF8, dataSize=8
118 andi t0, t2, 0x4, flags=(EZF,), dataSize=2
119 bri t0, label("globalCSDescriptor"), flags=(CEZF,)
120 ld t6, tsl, [1, t0, t6], dataSize=8
121 bri t0, label("processCSDescriptor")
122globalCSDescriptor:
123 ld t6, tsg, [1, t0, t6], dataSize=8
124processCSDescriptor:
125 chks t2, t6, dataSize=8
126
127 # This actually updates state which is wrong. It should wait until we know
128 # we're not going to fault. Unfortunately, that's hard to do.
129 wrdl cs, t6, t2
130 wrsel cs, t2
131
132 #CPL = temp_CPL
133
134
135###
136### Get the new stack pointer and stack segment off the old stack if necessary,
137### and piggyback on the logic to check the new RIP value.
138###
139 #IF ((64BIT_MODE) || (temp_CPL!=CPL))
140 #{
141
142 #(64BIT_MODE)
143 andi t0, t4, 0xE, flags=(EZF,)
144 # Since we just found out we're in 64 bit mode, take advantage and
145 # do the appropriate RIP checks.
146 bri t0, label("doPopStackStuffAndCheckRIP"), flags=(CEZF,)
147
148 # Here, we know we're -not- in 64 bit mode, so we should do the
149 # appropriate/other RIP checks.
150 # if temp_RIP > CS.limit throw #GP(0)
151 rdlimit t6, cs
152 subi t0, t1, t6, flags=(ECF,)
153 fault "new GeneralProtection(0)", flags=(CECF,)
154
155 #(temp_CPL!=CPL)
156 srli t7, t4, 4
157 xor t7, t7, t5
158 andi t0, t7, 0x3, flags=(EZF,)
159 bri t0, label("doPopStackStuff"), flags=(nCEZF,)
160 # We can modify user visible state here because we're know
161 # we're done with things that can fault.
162 addi rsp, rsp, "3 * env.stackSize"
163 bri t0, label("fallThroughPopStackStuff")
164
165doPopStackStuffAndCheckRIP:
166 # Check if the RIP is canonical.
167 sra t7, t1, 47, flags=(EZF,), dataSize=ssz
168 # if t7 isn't 0 or -1, it wasn't canonical.
169 bri t0, label("doPopStackStuff"), flags=(CEZF,)
170 addi t0, t7, 1, flags=(EZF,), dataSize=ssz
171 fault "new GeneralProtection(0)", flags=(nCEZF,)
172
173doPopStackStuff:
174 # POP.v temp_RSP
175 ld t6, ss, [1, t0, rsp], "3 * env.dataSize", dataSize=ssz
176 # POP.v temp_SS
177 ld t2, ss, [1, t0, rsp], "4 * env.dataSize", dataSize=ssz
178 # SS = READ_DESCRIPTOR (temp_SS, ss_chk)
179 andi t0, t2, 0xFC, flags=(EZF,), dataSize=2
180 bri t0, label("processSSDescriptor"), flags=(CEZF,)
181 andi t7, t2, 0xF8, dataSize=8
182 andi t0, t2, 0x4, flags=(EZF,), dataSize=2
183 bri t0, label("globalSSDescriptor"), flags=(CEZF,)
184 ld t7, tsl, [1, t0, t7], dataSize=8
185 bri t0, label("processSSDescriptor")
186globalSSDescriptor:
187 ld t7, tsg, [1, t0, t7], dataSize=8
188processSSDescriptor:
189 chks t2, t7, dataSize=8
190
191 # This actually updates state which is wrong. It should wait until we know
192 # we're not going to fault. Unfortunately, that's hard to do.
193 wrdl cs, t7, t2
194 wrsel cs, t2
195
196###
197### From this point downwards, we can't fault. We can update user visible state.
198###
199 # RSP.s = temp_RSP
200 mov rsp, rsp, t6, dataSize=ssz
201
202 #}
203
204fallThroughPopStackStuff:
205
206 #IF (changing CPL)
207 #{
208 srli t7, t4, 4
209 xor t7, t7, t5
210 andi t0, t7, 0x3, flags=(EZF,)
211 bri t0, 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 # VIF,VIP,IOPL only changed if (old_CPL = 0)
228 # IF only changed if (old_CPL <= old_RFLAGS.IOPL)
229 # VM unchanged
230 # RF cleared
231
232 #RIP = temp_RIP
233 wrip t0, t1, dataSize=ssz
234};
235
236def macroop IRET_VIRT {
237 panic "Virtual mode iret isn't implemented!"
238};
239'''
57#let {{
58# class INT(Inst):
59# "GenFault ${new UnimpInstFault}"
60# class INTO(Inst):
61# "GenFault ${new UnimpInstFault}"
240#let {{
241# class INT(Inst):
242# "GenFault ${new UnimpInstFault}"
243# class INTO(Inst):
244# "GenFault ${new UnimpInstFault}"
62# class IRET(Inst):
63# "GenFault ${new UnimpInstFault}"
64# class IRETD(Inst):
65# "GenFault ${new UnimpInstFault}"
66# class IRETQ(Inst):
67# "GenFault ${new UnimpInstFault}"
68#}};
245#}};