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CPU: Implement fixed dcache/scratchpad

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This commit is contained in:
Connor McLaughlin 2019-09-14 13:52:57 +10:00
parent ced3038e73
commit 0726095f00
2 changed files with 63 additions and 3 deletions
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13
src/pse/cpu_core.h
View file

@ -2,6 +2,7 @@
#include "common/bitfield.h" #include "common/bitfield.h"
#include "cpu_types.h" #include "cpu_types.h"
#include "types.h" #include "types.h"
#include <array>
class StateWrapper; class StateWrapper;
@ -12,7 +13,11 @@ namespace CPU {
class Core class Core
{ {
public: public:
static constexpr VirtualMemoryAddress RESET_VECTOR = 0xbfc00000; static constexpr VirtualMemoryAddress RESET_VECTOR = UINT32_C(0xBFC00000);
static constexpr PhysicalMemoryAddress DCACHE_LOCATION = UINT32_C(0x1F800000);
static constexpr PhysicalMemoryAddress DCACHE_LOCATION_MASK = UINT32_C(0xFFFFFC00);
static constexpr PhysicalMemoryAddress DCACHE_OFFSET_MASK = UINT32_C(0x000003FF);
static constexpr PhysicalMemoryAddress DCACHE_SIZE = UINT32_C(0x00000400);
Core(); Core();
~Core(); ~Core();
@ -40,6 +45,9 @@ private:
template<MemoryAccessType type, MemoryAccessSize size, bool is_instruction_fetch, bool raise_exceptions> template<MemoryAccessType type, MemoryAccessSize size, bool is_instruction_fetch, bool raise_exceptions>
bool DoMemoryAccess(VirtualMemoryAddress address, u32& value); bool DoMemoryAccess(VirtualMemoryAddress address, u32& value);
template<MemoryAccessType type, MemoryAccessSize size>
void DoScratchpadAccess(PhysicalMemoryAddress address, u32& value);
u8 ReadMemoryByte(VirtualMemoryAddress addr); u8 ReadMemoryByte(VirtualMemoryAddress addr);
u16 ReadMemoryHalfWord(VirtualMemoryAddress addr); u16 ReadMemoryHalfWord(VirtualMemoryAddress addr);
u32 ReadMemoryWord(VirtualMemoryAddress addr); u32 ReadMemoryWord(VirtualMemoryAddress addr);
@ -88,6 +96,9 @@ private:
u32 m_cache_control = 0; u32 m_cache_control = 0;
Cop0Registers m_cop0_regs = {}; Cop0Registers m_cop0_regs = {};
// data cache (used as scratchpad)
std::array<u8, DCACHE_SIZE> m_dcache = {};
}; };
extern bool TRACE_EXECUTION; extern bool TRACE_EXECUTION;

53
src/pse/cpu_core.inl
View file

@ -18,7 +18,14 @@ bool Core::DoMemoryAccess(VirtualMemoryAddress address, u32& value)
return true; return true;
} }
if (!m_bus->DispatchAccess<type, size>(address, address & UINT32_C(0x1FFFFFFF), value)) const PhysicalMemoryAddress phys_addr = address & UINT32_C(0x1FFFFFFF);
if ((phys_addr & DCACHE_LOCATION_MASK) == DCACHE_LOCATION)
{
DoScratchpadAccess<type, size>(phys_addr, value);
return true;
}
if (!m_bus->DispatchAccess<type, size>(address, phys_addr, value))
{ {
Panic("Bus error"); Panic("Bus error");
return false; return false;
@ -44,6 +51,13 @@ bool Core::DoMemoryAccess(VirtualMemoryAddress address, u32& value)
return true; return true;
} }
const PhysicalMemoryAddress phys_addr = address & UINT32_C(0x1FFFFFFF);
if ((phys_addr & DCACHE_LOCATION_MASK) == DCACHE_LOCATION)
{
DoScratchpadAccess<type, size>(phys_addr, value);
return true;
}
if (!m_bus->DispatchAccess<type, size>(address, address & UINT32_C(0x1FFFFFFF), value)) if (!m_bus->DispatchAccess<type, size>(address, address & UINT32_C(0x1FFFFFFF), value))
{ {
Panic("Bus error"); Panic("Bus error");
@ -56,7 +70,8 @@ bool Core::DoMemoryAccess(VirtualMemoryAddress address, u32& value)
case 0x05: // KSEG1 - physical memory uncached case 0x05: // KSEG1 - physical memory uncached
{ {
if (!m_bus->DispatchAccess<type, size>(address, address & UINT32_C(0x1FFFFFFF), value)) const PhysicalMemoryAddress phys_addr = address & UINT32_C(0x1FFFFFFF);
if (!m_bus->DispatchAccess<type, size>(address, phys_addr, value))
{ {
Panic("Bus error"); Panic("Bus error");
return false; return false;
@ -91,4 +106,38 @@ bool Core::DoMemoryAccess(VirtualMemoryAddress address, u32& value)
} }
} }
template<MemoryAccessType type, MemoryAccessSize size>
void CPU::Core::DoScratchpadAccess(PhysicalMemoryAddress address, u32& value)
{
const PhysicalMemoryAddress cache_offset = address & DCACHE_OFFSET_MASK;
if constexpr (size == MemoryAccessSize::Byte)
{
if constexpr (type == MemoryAccessType::Read)
value = ZeroExtend32(m_dcache[cache_offset]);
else
m_dcache[cache_offset] = Truncate8(value);
}
else if constexpr (size == MemoryAccessSize::HalfWord)
{
if constexpr (type == MemoryAccessType::Read)
{
u16 temp;
std::memcpy(&temp, &m_dcache[cache_offset], sizeof(temp));
value = ZeroExtend32(temp);
}
else
{
u16 temp = Truncate16(value);
std::memcpy(&m_dcache[cache_offset], &temp, sizeof(temp));
}
}
else if constexpr (size == MemoryAccessSize::Word)
{
if constexpr (type == MemoryAccessType::Read)
std::memcpy(&value, &m_dcache[cache_offset], sizeof(value));
else
std::memcpy(&m_dcache[cache_offset], &value, sizeof(value));
}
}
} // namespace CPU } // namespace CPU