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mirror of https://github.com/TomHarte/CLK.git synced 2024-06-25 18:30:07 +00:00

Be consistent in shadowing physical addresses.

This commit is contained in:
Thomas Harte 2024-01-03 15:02:54 -05:00
parent ad31c50dfd
commit cf00a709ec
3 changed files with 6 additions and 12 deletions

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@ -954,7 +954,7 @@ class ConcreteMachine:
// get by adding periodic NOPs within their copy-to-shadow step.
//
// Maybe the interaction with 2.8Mhz refresh isn't as straightforward as I think?
const bool is_shadowed = memory_.is_shadowed(address);
const bool is_shadowed = memory_.is_shadowed(region, address);
is_1Mhz |= is_shadowed;
// Use a very broad test for flushing video: any write to $e0 or $e1, or any write that is shadowed.

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@ -633,18 +633,15 @@ class MemoryMap {
// adjust as required.
// The below encapsulates an assumption that Apple intends to shadow physical addresses (i.e. after mapping).
// If the Apple shadows logical addresses (i.e. prior to mapping) then see commented out alternatives.
// I couldn't really find clear documentation on this.
const Region &region(uint32_t address) { return regions[region_map[address >> 8]]; }
uint8_t read(const Region &region, uint32_t address) {
return region.read ? region.read[address] : 0xff;
}
bool is_shadowed(uint32_t address) const {
// Logical mapping alternative:
// shadow_pages[((&region.write[address] - ram_base) >> 10) & 127] & shadow_banks[address >> 17]
return shadow_pages[(address >> 10) & 127] & shadow_banks[address >> 17];
bool is_shadowed(const Region &region, uint32_t address) const {
return shadow_pages[((&region.write[address] - ram_base) >> 10) & 127] & shadow_banks[address >> 17];
// Quick notes on contortions above:
//
@ -666,11 +663,8 @@ class MemoryMap {
}
region.write[address] = value;
const bool shadowed = is_shadowed(address);
const bool shadowed = is_shadowed(region, address);
shadow_base[shadowed][(&region.write[address] - ram_base) & shadow_mask[shadowed]] = value;
// Logical mapping alternative:
// shadow_base[shadowed][address & shadow_mask[shadowed]]
}
};

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@ -369,7 +369,7 @@ namespace {
while(logical < [next intValue]) {
[[maybe_unused]] const auto &region =
self->_memoryMap.regions[self->_memoryMap.region_map[logical]];
const bool isShadowed = _memoryMap.is_shadowed(logical << 8);
const bool isShadowed = _memoryMap.is_shadowed(region, logical << 8);
XCTAssertEqual(
isShadowed,