Starlet: re-sample the interrupt lines on HW_ARMFIQMASK writes too

Review of d486779f50 (StarOS decision 44):
- A write to HW_ARMFIQMASK re-samples the attached core's IRQ and FIQ lines,
  as writes to HW_ARMIRQFLAG and HW_ARMIRQMASK do.
- Tests: FIQ masking and unmasking of a latched cause (wide and
  byte-assembled writes, then an acknowledgement); two pending IRQ sources,
  where acknowledging one keeps the line asserted and acknowledging the
  last lowers it.

The attached core cannot be used after it is destroyed: Starlet::Shutdown
resets m_core then m_memory with nothing in between, ~Starlet destroys
m_core (declared after m_memory) first, Init attaches only after the last
path that can fail, StarletMemory::Reset keeps the core, which is still
alive, and the probe's core is a local declared after its memory.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

Source/Core/Core/IOS/Starlet/StarletMemory.cpp

@@ -335,6 +335,7 @@ constexpr u64 TIMER_CLOCK_DIVISOR = 128;
 constexpr u32 HW_ALARM = HW_BASE + 0x14;
 constexpr u32 HW_ARMIRQFLAG = HW_BASE + 0x38;
 constexpr u32 HW_ARMIRQMASK = HW_BASE + 0x3c;
+constexpr u32 HW_ARMFIQMASK = HW_BASE + 0x40;
 constexpr u32 HW_GPIO_ENABLE = HW_BASE + 0xdc;
 constexpr u32 HW_GPIO_OUT = HW_BASE + 0xe0;
 constexpr u32 HW_GPIO_DIR = HW_BASE + 0xe4;
@@ -1113,8 +1114,11 @@ void StarletMemory::AttachInterruptLines(ARMCore* core)
 
 void StarletMemory::UpdateInterruptLines(u32 address)
 {
-  if (m_interrupt_core == nullptr || (address != HW_ARMIRQFLAG && address != HW_ARMIRQMASK))
+  if (m_interrupt_core == nullptr ||
+      (address != HW_ARMIRQFLAG && address != HW_ARMIRQMASK && address != HW_ARMFIQMASK))
+  {
     return;
+  }
   const WiiIPC& ipc = m_system.GetWiiIPC();
   m_interrupt_core->SetIRQLine(ipc.IsStarletIRQAsserted());
   m_interrupt_core->SetFIQLine(ipc.IsStarletFIQAsserted());

Source/Core/Core/IOS/Starlet/StarletMemory.h

@@ -83,11 +83,11 @@ public:
   // range to its bus slow path, with the instruction address. `core` gives that address.
   void SetWatchCore(const ARMCore* core);
   // The core whose IRQ and FIQ lines follow Hollywood's ARM interrupt registers. A write to
-  // HW_ARMIRQFLAG or HW_ARMIRQMASK re-samples both lines at once, as the level-sensitive
-  // Hollywood output follows them on hardware, instead of at the next scheduler slice: an
-  // acknowledged or masked interrupt is never taken again in between. Raising a cause still
-  // reaches the line at the next slice. The owner of both attaches the core once it exists and
-  // destroys it before the memory.
+  // HW_ARMIRQFLAG, HW_ARMIRQMASK or HW_ARMFIQMASK re-samples both lines at once, as the
+  // level-sensitive Hollywood output follows them on hardware, instead of at the next scheduler
+  // slice: an acknowledged or masked interrupt is never taken again in between. Raising a cause
+  // still reaches the line at the next slice. The owner of both attaches the core once it exists
+  // and destroys it before the memory.
   void AttachInterruptLines(ARMCore* core);
   void Reset();
   void DoState(PointerWrap& p);