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UserspaceEmulator: Implement STOSB/STOSW/STOSD

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...and add a template to handle REP* instruction prefixes. This can be
further generalized, but let's go one step at a time.
This commit is contained in:
Andreas Kling 2020-07-11 22:12:37 +02:00
parent 6688ce41b2
commit 0af485dfff
2 changed files with 83 additions and 3 deletions
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81
DevTools/UserspaceEmulator/SoftCPU.cpp
View file

@ -157,6 +157,38 @@ u32 SoftCPU::pop32()
return value;
}
template<bool check_zf, typename Callback>
void SoftCPU::do_once_or_repeat(const X86::Instruction& insn, Callback callback)
{
if (!insn.has_rep_prefix())
return callback();
if (insn.has_address_size_override_prefix()) {
while (cx()) {
callback();
set_cx(cx() - 1);
if constexpr (check_zf) {
if (insn.rep_prefix() == X86::Prefix::REPZ && !zf())
break;
if (insn.rep_prefix() == X86::Prefix::REPNZ && zf())
break;
}
}
return;
}
while (ecx()) {
callback();
set_ecx(ecx() - 1);
if constexpr (check_zf) {
if (insn.rep_prefix() == X86::Prefix::REPZ && !zf())
break;
if (insn.rep_prefix() == X86::Prefix::REPNZ && zf())
break;
}
}
}
template<typename Destination, typename Source>
static typename TypeDoubler<Destination>::type op_xor(SoftCPU& cpu, const Destination& dest, const Source& src)
{
@ -1064,9 +1096,52 @@ void SoftCPU::SMSW_RM16(const X86::Instruction&) { TODO(); }
void SoftCPU::STC(const X86::Instruction&) { TODO(); }
void SoftCPU::STD(const X86::Instruction&) { TODO(); }
void SoftCPU::STI(const X86::Instruction&) { TODO(); }
void SoftCPU::STOSB(const X86::Instruction&) { TODO(); }
void SoftCPU::STOSD(const X86::Instruction&) { TODO(); }
void SoftCPU::STOSW(const X86::Instruction&) { TODO(); }
void SoftCPU::STOSB(const X86::Instruction& insn)
{
if (insn.has_address_size_override_prefix()) {
do_once_or_repeat<false>(insn, [&] {
write_memory8({ es(), di() }, al());
set_di(di() + (df() ? -1 : 1));
});
} else {
do_once_or_repeat<false>(insn, [&] {
write_memory8({ es(), edi() }, al());
set_edi(edi() + (df() ? -1 : 1));
});
}
}
void SoftCPU::STOSD(const X86::Instruction& insn)
{
if (insn.has_address_size_override_prefix()) {
do_once_or_repeat<false>(insn, [&] {
write_memory32({ es(), di() }, eax());
set_di(di() + (df() ? -4 : 4));
});
} else {
do_once_or_repeat<false>(insn, [&] {
write_memory32({ es(), edi() }, eax());
set_edi(edi() + (df() ? -4 : 4));
});
}
}
void SoftCPU::STOSW(const X86::Instruction& insn)
{
if (insn.has_address_size_override_prefix()) {
do_once_or_repeat<false>(insn, [&] {
write_memory16({ es(), di() }, ax());
set_di(di() + (df() ? -2 : 2));
});
} else {
do_once_or_repeat<false>(insn, [&] {
write_memory16({ es(), edi() }, ax());
set_edi(edi() + (df() ? -2 : 2));
});
}
}
void SoftCPU::STR_RM16(const X86::Instruction&) { TODO(); }
void SoftCPU::UD0(const X86::Instruction&) { TODO(); }
void SoftCPU::UD1(const X86::Instruction&) { TODO(); }

5
DevTools/UserspaceEmulator/SoftCPU.h
View file

@ -190,6 +190,7 @@ public:
bool af() const { return m_eflags & Flags::AF; }
bool pf() const { return m_eflags & Flags::PF; }
bool cf() const { return m_eflags & Flags::CF; }
bool df() const { return m_eflags & Flags::DF; }
void set_flag(Flags::Flag flag, bool value)
{
@ -205,6 +206,7 @@ public:
void set_af(bool value) { set_flag(Flags::AF, value); }
void set_pf(bool value) { set_flag(Flags::PF, value); }
void set_cf(bool value) { set_flag(Flags::CF, value); }
void set_df(bool value) { set_flag(Flags::DF, value); }
void set_flags_oszapc(u32 new_flags)
{
@ -785,6 +787,9 @@ private:
template<bool update_dest, typename Op>
void generic_reg8_RM8(Op, const X86::Instruction&);
template<bool check_zf, typename Callback>
void do_once_or_repeat(const X86::Instruction& insn, Callback);
private:
Emulator& m_emulator;