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arch-x86: Implement real mode far call.

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Change-Id: I720a0b0e4aa227171c59804d899baba64b8d320b
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/55623
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This commit is contained in:
Gabe Black
2022-01-17 00:27:23 -08:00
parent 7468d4169c
commit d73ce0f593
2 changed files with 76 additions and 1 deletions
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6
src/arch/x86/isa/decoder/one_byte_opcodes.isa
View File

@@ -305,6 +305,7 @@
0x1: CQO(rAv,rDv);
0x2: decode MODE_SUBMODE {
0x0: UD2();
0x4: CALL_FAR_REAL(Iz);
default: WarnUnimpl::call_far_Ap();
}
0x3: WarnUnimpl::fwait(); //aka wait
@@ -568,7 +569,10 @@
0x0: INC(Ev);
0x1: DEC(Ev);
0x2: CALL_NEAR(Ev);
0x3: WarnUnimpl::call_far_Mp();
0x3: decode MODE_SUBMODE {
0x4: CALL_FAR_REAL(Mz);
default: WarnUnimpl::call_far_Mp();
}
0x4: JMP(Ev);
0x5: decode MODE_SUBMODE {
0x0: JMP_FAR(Mz);

71
src/arch/x86/isa/insts/general_purpose/control_transfer/call.py
View File

@@ -92,6 +92,77 @@ def macroop CALL_NEAR_P
subi rsp, rsp, dsz, dataSize=ssz
wripi t1, 0
};
def macroop CALL_FAR_REAL_I {
.function_call
.control_indirect
limm t1, imm, dataSize=8
# Multiply the data size by 8 to get the size of the offset in bits.
limm t3, dsz, dataSize=8
slli t3, t3, 3, dataSize=8
# Extract the selector from the far pointer.
srl t2, t1, t3, dataSize=8
zexti t2, t2, 15, dataSize=8
# Extract the offset from the far pointer.
zext t1, t1, t3, dataSize=8
# Compute the base.
slli t3, t2, 4, dataSize=8
# Make sure pushing the RIP will work after we push cs.
cda ss, [1, t0, rsp], "-env.dataSize * 2", addressSize=ssz
# Push CS.
rdsel t4, cs, dataSize=8
st t4, ss, [1, t0, rsp], "-env.dataSize", addressSize=ssz
# Push RIP.
rdip t7
st t7, ss, [1, t0, rsp], "-env.dataSize * 2", addressSize=ssz
subi rsp, rsp, "env.dataSize * 2", dataSize=ssz
# Install the new selector, base and RIP values.
wrsel cs, t2, dataSize=2
wrbase cs, t3, dataSize=8
wrip t1, t0
};
def macroop CALL_FAR_REAL_M {
.function_call
.control_indirect
lea t1, seg, sib, disp, dataSize=asz
# Load the selector.
ld t2, seg, [1, t0, t1], dsz, dataSize=2
# Load the offset.
ld t1, seg, [1, t0, t1]
# Compute the base.
zexti t3, t2, 15, dataSize=8
slli t3, t3, 4, dataSize=8
# Make sure pushing the RIP will work after we push cs.
cda ss, [1, t0, rsp], "-env.dataSize * 2", addressSize=ssz
# Push CS.
rdsel t4, cs, dataSize=8
st t4, ss, [1, t0, rsp], "-env.dataSize", addressSize=ssz
# Push RIP.
rdip t7
st t7, ss, [1, t0, rsp], "-env.dataSize * 2", addressSize=ssz
subi rsp, rsp, "env.dataSize * 2", dataSize=ssz
# Install the new selector, base and RIP values.
wrsel cs, t2, dataSize=2
wrbase cs, t3, dataSize=8
wrip t1, t0
};
def macroop CALL_FAR_REAL_P {
panic "Far call in real mode doesn't support RIP addressing."
};
'''
#let {{
# class CALL(Inst):