Eliminate hacky setup states

There still probably needs to be another state for CMD0 or such, but that can be handled separately.

Source/Core/Core/HW/EXI/EXI_DeviceSD.cpp

@@ -59,49 +59,24 @@ CEXISD::CEXISD(Core::System& system, int channel_num) : IEXIDevice(system)
 
 void CEXISD::ImmWrite(u32 data, u32 size)
 {
-  if (state == State::Uninitialized || state == State::GetId)
+  while (size--)
   {
-    // Get ID command
+    u8 byte = data >> 24;
-    INFO_LOG_FMT(EXPANSIONINTERFACE, "SD: EXI_GetID detected (size = {:x}, data = {:x})", size,
+    WriteByte(byte);
-                 data);
+    data <<= 8;
-    state = State::GetId;
-  }
-  else
-  {
-    while (size--)
-    {
-      u8 byte = data >> 24;
-      WriteByte(byte);
-      data <<= 8;
-    }
   }
 }
 
 u32 CEXISD::ImmRead(u32 size)
 {
-  if (state == State::Uninitialized)
+  u32 res = 0;
+  u32 position = 0;
+  while (size--)
   {
-    // ?
+    u8 byte = ReadByte();
-    return 0;
+    res |= byte << (24 - (position++ * 8));
-  }
-  else if (state == State::GetId)
-  {
-    INFO_LOG_FMT(EXPANSIONINTERFACE, "SD: EXI_GetID finished (size = {:x})", size);
-    state = State::ReadyForCommand;
-    // Same signed/unsigned mismatch in libogc; it wants -1
-    return -1;
-  }
-  else
-  {
-    u32 res = 0;
-    u32 position = 0;
-    while (size--)
-    {
-      u8 byte = ReadByte();
-      res |= byte << (24 - (position++ * 8));
-    }
-    return res;
   }
+  return res;
 }
 
 void CEXISD::ImmReadWrite(u32& data, u32 size)
@@ -490,7 +465,8 @@ u8 CEXISD::ReadByte()
   {
     if (response.empty())
     {
-      // WARN_LOG_FMT(EXPANSIONINTERFACE, "Attempted to read from empty SD queue");
+      // Note that SD cards are detected by trying to read a device ID, and getting 0xffffffff back;
+      // this behavior is required for correct handling.
       return 0xff;
     }
     else

Source/Core/Core/HW/EXI/EXI_DeviceSD.h

@@ -173,10 +173,6 @@ private:
 
   enum class State
   {
-    // Hacky setup
-    Uninitialized,
-    GetId,
-    // Actual states for transmiting and receiving
     ReadyForCommand,
     ReadyForAppCommand,
     SingleBlockRead,
@@ -232,7 +228,7 @@ private:
   File::IOFile m_card;
 
   // STATE_TO_SAVE
-  State state = State::Uninitialized;
+  State state = State::ReadyForCommand;
   BlockState block_state = BlockState::Nothing;
   u32 command_position = 0;
   u32 block_position = 0;