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It's differing mildly from DataPointResolver, but segue towards a world of real data.

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This commit is contained in:
Thomas Harte 2023-10-05 17:06:00 -04:00
parent eb100e3b29
commit ada411c0d8
2 changed files with 89 additions and 4 deletions
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88
InstructionSets/x86/Implementation/PerformImplementation.hpp
View File

@ -197,12 +197,92 @@ template <
[[maybe_unused]] IOT &io
) {
using IntT = typename DataSizeType<data_size>::type;
using AddressT = typename AddressT<is_32bit(model)>::type;
// Establish source() and destination() shorthand to fetch data if necessary.
IntT fetched_data;
bool needs_writeback = false;
IntT fetched_data = 0, original_data = 0;
Source segment;
AddressT address;
static constexpr IntT zero = 0;
auto data = [&](DataPointer source) -> IntT& {
// TODO.
// Rules:
//
// * if this is a memory access, set target_address and break;
// * otherwise return the appropriate value.
switch(source.source<false>()) {
case Source::eAX:
switch(data_size) {
default: return registers.al();
case DataSize::Word: return registers.ax();
case DataSize::DWord: return registers.eax();
}
case Source::eCX:
switch(data_size) {
default: return registers.cl();
case DataSize::Word: return registers.cx();
case DataSize::DWord: return registers.ecx();
}
case Source::eDX:
switch(data_size) {
default: return registers.dl();
case DataSize::Word: return registers.dx();
case DataSize::DWord: return registers.edx();
}
case Source::eBX:
switch(data_size) {
default: return registers.bl();
case DataSize::Word: return registers.bx();
case DataSize::DWord: return registers.ebx();
}
case Source::eSPorAH:
switch(data_size) {
default: return registers.ah();
case DataSize::Word: return registers.sp();
case DataSize::DWord: return registers.esp();
}
case Source::eBPorCH:
switch(data_size) {
default: return registers.ch();
case DataSize::Word: return registers.bp();
case DataSize::DWord: return registers.ebp();
}
case Source::eSIorDH:
switch(data_size) {
default: return registers.dh();
case DataSize::Word: return registers.si();
case DataSize::DWord: return registers.esi();
}
case Source::eDIorBH:
switch(data_size) {
default: return registers.bh();
case DataSize::Word: return registers.di();
case DataSize::DWord: return registers.edi();
}
case Source::ES: return registers.es();
case Source::CS: return registers.cs();
case Source::SS: return registers.ss();
case Source::DS: return registers.ds();
case Source::FS: return registers.fs();
case Source::GS: return registers.gs();
case Source::Immediate: // TODO (here the use of a reference falls down?)
case Source::None: return zero;
case Source::Indirect: // TODO
case Source::IndirectNoBase: // TODO
case Source::DirectAddress:
address = instruction.offset();
break;
}
// If execution has reached here then a memory fetch is required.
// Do it and exit.
segment = Source::DS; // TODO.
fetched_data = original_data = memory.template read<IntT>(segment, address);
return fetched_data;
};
@ -225,7 +305,7 @@ template <
}
// Write to memory if required to complete this operation.
if(needs_writeback) {
if(original_data != fetched_data) {
// TODO.
}
}

5
InstructionSets/x86/Model.hpp
View File

@ -9,6 +9,8 @@
#ifndef Model_h
#define Model_h
#include <cstdint>
namespace InstructionSet::x86 {
enum class Model {
@ -20,6 +22,9 @@ enum class Model {
static constexpr bool is_32bit(Model model) { return model >= Model::i80386; }
template <bool is_32bit> struct AddressT { using type = uint16_t; };
template <> struct AddressT<true> { using type = uint32_t; };
}
#endif /* Model_h */