diff --git a/src/nba/include/nba/rom/gpio/gpio.hpp b/src/nba/include/nba/rom/gpio/gpio.hpp
index a405a22..eec8504 100644
--- a/src/nba/include/nba/rom/gpio/gpio.hpp
+++ b/src/nba/include/nba/rom/gpio/gpio.hpp
@@ -36,7 +36,7 @@ struct GPIO {
     return nullptr;
   }
 
-  bool IsReadable() const {
+  bool ALWAYS_INLINE IsReadable() const {
     return allow_reads;
   }
 
diff --git a/src/nba/src/bus/bus.cpp b/src/nba/src/bus/bus.cpp
index 1df7ac4..5213abf 100644
--- a/src/nba/src/bus/bus.cpp
+++ b/src/nba/src/bus/bus.cpp
@@ -318,6 +318,9 @@ auto Bus::ReadWord(u32 address, int access) -> u32 {
 }
 
 void Bus::WriteByte(u32 address, u8  value, int access) {
+  // address == 0xe00'5555 && value == 0xaa --> flash
+  // address >= 0xe00'0000 && address <= 0xe00'ffff --> sram
+  // address >= 0x800'0000 && address <= 0xe00'0000 --> eeprom
   Write<u8>(address, access, value);
 }