Remove Overlayhader and support loading overlays

include/PSX/File/cd_file_types.hpp

@@ -7,13 +7,15 @@ namespace JabyEngine {
     enum struct CDFileType : uint8_t {
         SimpleTIM = 0,
         CopyTo,
+        Overlay,
     };
 
     struct __no_align CDFile {
         union __no_align Payload {
-            uint32_t  empty;
+            uint32_t  raw;
             SimpleTIM simple_tim;
             CopyTo    copy_to;
+            Overlay   overlay;
         };
 
         uint8_t    rel_lba_idx;
@@ -31,6 +33,10 @@ namespace JabyEngine {
         static constexpr CDFile copy_to(uint8_t rel_lba_idx, uint32_t* dst) {
             return CDFile{.rel_lba_idx = rel_lba_idx, .type = CDFileType::CopyTo, .payload = {.copy_to = CopyTo{dst}}};
         }
+
+        static constexpr CDFile overlay(uint8_t rel_lba_idx, uint32_t* overlay_dst) {
+            return CDFile{.rel_lba_idx = rel_lba_idx, .type = CDFileType::Overlay, .payload = {.overlay = Overlay{overlay_dst}}};
+        }
     };
 }
 #endif //!__JABYENGINE_CD_FILE_TYPES_HPP__

include/PSX/File/file_types.hpp

@@ -42,5 +42,7 @@ namespace JabyEngine {
     struct __no_align CopyTo {
         uint32_t* dst;
     };
+
+    typedef CopyTo Overlay;
 }
 #endif // !__JABYENGINE_FILE_TYPES_HPP__

include/PSX/Overlay/overlay.hpp

@@ -3,11 +3,9 @@
 #include "../AutoLBA/auto_lba.hpp"
 
 namespace JabyEngine {
-    struct __attribute__((packed)) OverlayHeader {
-        void   (*execute)();
-        uint16_t lba_size; //< The size of the OverlayLBA section
-    };
-
     typedef AutoLBAEntry OverlayLBA;
+
+    // Can be used to create dummy values to trick LZ4 into compressing an uncompressed overlay
+    #define __create_dummy_fill(length) static const uint8_t __section(".keep.dummy") __used DummyFilling[length] = {0x0}
 }
 #endif //!__JABYENGINE_OVERLAY__HPP__

include/PSX/Overlay/overlay_declaration.hpp

@@ -4,10 +4,7 @@
 // No include here because this header should be included in a namespace and we don't want multiple namespace definitions of OverlayHeader and OverlayLBA
 
 #include "../AutoLBA/auto_lba_declaration.hpp"
-extern const JabyEngine::OverlayHeader overlay_header;
 
 #define __declare_overlay_header(function, enum_struct) \
-__declare_lba_header(enum_struct); \
-[[gnu::used]] \
-const JabyEngine::OverlayHeader __section(".header") overlay_header = {.execute = &function, .lba_size = static_cast<uint16_t>(enum_struct::EndOfRequest)};
+__declare_lba_header(enum_struct)
 #endif //!__JABYENGINE_OVERLAY_DECLARATION__HPP__

include/PSX/jabyengine_defines.h

@@ -3,7 +3,7 @@
 #include "jabyengine_config.hpp"
 #include "../stddef.h"
 
-#define __keep          __attribute__((used))
+#define __used          __attribute__((used))
 #define __no_align      __attribute__((packed))
 #define __no_inline     __attribute__((noinline))
 #define __always_inline __attribute__((always_inline))