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Okay, this is a bit desperate, but worth investigation.

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This commit is contained in:
Thomas Harte 2017-02-27 08:39:53 -05:00
parent fe07cd0248
commit 1af415a88e
1 changed files with 24 additions and 6 deletions
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30
StaticAnalyser/Atari/StaticAnalyser.cpp
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@ -34,8 +34,8 @@ static void DeterminePagingFor2kCartridge(StaticAnalyser::Target &target, const
StaticAnalyser::MOS6502::Disassembly high_location_disassembly =
StaticAnalyser::MOS6502::Disassemble(segment.data, high_location_mapper, {entry_address, break_address});
StaticAnalyser::MOS6502::Disassembly full_range_disassembly =
StaticAnalyser::MOS6502::Disassemble(segment.data, full_range_mapper, {entry_address, break_address});
// StaticAnalyser::MOS6502::Disassembly full_range_disassembly =
// StaticAnalyser::MOS6502::Disassemble(segment.data, full_range_mapper, {entry_address, break_address});
// if there are no subroutines in the top 2kb of memory then this isn't a CommaVid
bool has_appropriate_subroutine_calls = false;
@ -56,19 +56,37 @@ static void DeterminePagingFor2kCartridge(StaticAnalyser::Target &target, const
// a CommaVid will use its RAM
if(all_writes.empty()) return;
bool has_appropriate_writes = false;
bool has_appropriate_accesses = false;
for(uint16_t address : all_writes)
{
const uint16_t masked_address = address & 0x1fff;
if(masked_address >= 0x1400 && masked_address < 0x1800)
{
has_appropriate_writes = true;
has_appropriate_accesses = true;
break;
}
}
// conclude that this is a CommaVid if it attempted to write something to the CommaVid RAM locations
if(has_appropriate_writes)
// in desperation, accept any kind of store that looks likely to be intended for large amounts of memory
bool has_wide_area_store = false;
if(!has_appropriate_accesses)
{
for(std::map<uint16_t, StaticAnalyser::MOS6502::Instruction>::value_type &entry : high_location_disassembly.instructions_by_address)
{
if(entry.second.operation == StaticAnalyser::MOS6502::Instruction::STA)
{
has_wide_area_store |= entry.second.addressing_mode == StaticAnalyser::MOS6502::Instruction::Indirect;
has_wide_area_store |= entry.second.addressing_mode == StaticAnalyser::MOS6502::Instruction::IndexedIndirectX;
has_wide_area_store |= entry.second.addressing_mode == StaticAnalyser::MOS6502::Instruction::IndirectIndexedY;
}
}
}
// conclude that this is a CommaVid if it attempted to write something to the CommaVid RAM locations;
// caveat: false positives aren't likely to be problematic; a false positive is a 2KB ROM that always addresses
// itself so as to land in ROM even if mapped as a CommaVid and this code is on the fence as to whether it
// attempts to modify itself but it probably doesn't
if(has_appropriate_accesses || has_wide_area_store)
{
target.atari.paging_model = StaticAnalyser::Atari2600PagingModel::CommaVid;
return;