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Cxbx-Reloaded
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VMManager identity mapping hack

This commit is contained in:
ergo720 2018-06-02 19:47:19 +02:00
parent c0bc5545bb
commit d8c42fc79b
1 changed files with 34 additions and 0 deletions
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34
src/CxbxKrnl/VMManager.cpp
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@ -169,6 +169,12 @@ dashboard from non-retail xbe?");
// Reserve the xbe image memory. Doing this now allows us to avoid calling XbAllocateVirtualMemory later
ConstructVMA(XBE_IMAGE_BASE, ROUND_UP_4K(CxbxKrnl_Xbe->m_Header.dwSizeofImage), UserRegion, ReservedVma, false, XBOX_PAGE_READWRITE);
// ergo720: another hack. On 128 MiB systems, also reserve the 64 MiB following the memory placeholder so that the VMManager
// is forbidden from making allocations there and the LLE OHCI can distinguish identity mapped addresses from contiguous addresses.
// Once LLE CPU and MMU are implemented, this can be removed
if (g_bIsRetail != true) {
ConstructVMA(XBE_IMAGE_BASE + XBE_MAX_VA, XBOX_MEMORY_SIZE, UserRegion, ReservedVma, true);
}
if (g_bIsChihiro) {
printf(LOG_PREFIX " Page table for Chihiro arcade initialized!\n");
@ -2401,9 +2407,37 @@ PAddr VMManager::TranslateVAddrToPAddr(const VAddr addr)
PAddr PAddr;
PMMPTE PointerPte;
MemoryRegionType Type = COUNTRegion;
Lock();
// ergo720: boring, this hack identity maps allocations served by VirtualAlloc to keep the LLE OHCI working (see OHCI_ReadHCCA
// for more details). Once LLE CPU and MMU are implemented, this can be removed
if (IS_USER_ADDRESS(addr)) { Type = UserRegion; }
else if (IS_PHYSICAL_ADDRESS(addr)) { Type = ContiguousRegion; }
else if (IS_SYSTEM_ADDRESS(addr)) { Type = SystemRegion; }
else if (IS_DEVKIT_ADDRESS(addr)) { Type = DevkitRegion; }
if (Type != COUNTRegion && Type != ContiguousRegion) {
if (IsValidVirtualAddress(addr)) {
if (Type == UserRegion) {
EmuWarning("Applying identity mapping hack to allocation at address 0x%X", addr);
Unlock();
RETURN(addr); // committed pages in the user region always use VirtualAlloc
}
VMAIter it = GetVMAIterator(addr, Type);
if (it != m_MemoryRegionArray[Type].RegionMap.end() && it->second.type != FreeVma && it->second.bFragmented) {
EmuWarning("Applying identity mapping hack to allocation at address 0x%X", addr);
Unlock();
RETURN(addr); // committed pages in the system-devkit regions can use VirtualAlloc because of fragmentation
}
}
else {
goto InvalidAddress;
}
}
PointerPte = GetPdeAddress(addr);
if (PointerPte->Hardware.Valid == 0) { // invalid pde -> addr is invalid
goto InvalidAddress;