Write a hello world of sorts for writing to SD card.

This just writes a file sd://helloworld.txt to the sd card.

It will form the basis for implementing save backup

include/core/DragonUtils.h

@@ -20,10 +20,29 @@ enum class NavigationInputSourceType
     BOTH
 };
 
+extern bool sdcard_mounted;
+
 /**
  * This function determines whether the joypad_inputs_t has analog or dpad positions/presses that could be considered for UI navigation.
  * If so, it will return the most prominent direction.
  */
 const UINavigationDirection determineUINavigationDirection(joypad_inputs_t inputs, NavigationInputSourceType sourceType);
 
+/**
+ * @brief mounts the SD card (if possible)
+ * 
+ */
+bool mountSDCard();
+
+/**
+ * @brief Writes the specified buffer to a file at the specified path.
+ * This should be a path starting with sd:/
+ * 
+ * @param path path starting with sd:/
+ * @param buffer buffer to write
+ * @param bufferSize size of the buffer
+ * @return size_t number of bytes written
+ */
+size_t writeBufferToFile(const char* path, const uint8_t* buffer, size_t bufferSize);
+
 #endif

include/menu/MenuFunctions.h

@@ -30,5 +30,8 @@ void gen1TeachPikachu(void* context, const void* param);
 void gen2ReceiveGSBall(void* context, const void* param);
 void gen2SetEventFlag(void* context, const void* param);
 
+//Temporary function.
+// TODO: should be removed!
+void writeFileToSD(void* context, const void* param);
 
 #endif

src/core/Application.cpp

@@ -1,5 +1,6 @@
 #include "core/Application.h"
 #include "scenes/IScene.h"
+#include "core/DragonUtils.h"
 
 static Application* appInstance = nullptr;
 static void resetInterruptHandler()
@@ -40,6 +41,7 @@ void Application::init()
 {
     // Based on example code https://github.com/DragonMinded/libdragon/wiki/OpenGL-on-N64
     debug_init_isviewer();
+    mountSDCard();
     //console_set_debug(true);
 
     joypad_init();

src/core/DragonUtils.cpp

@@ -1,5 +1,7 @@
 #include "core/DragonUtils.h"
 
+bool sdcard_mounted = false;
+
 static uint8_t ANALOG_STICK_THRESHOLD = 30;
 
 const UINavigationDirection determineUINavigationDirection(joypad_inputs_t inputs, NavigationInputSourceType sourceType)
@@ -45,4 +47,30 @@ const UINavigationDirection determineUINavigationDirection(joypad_inputs_t input
         }
     }
     return UINavigationDirection::MAX;
+}
+
+bool mountSDCard()
+{
+    sdcard_mounted = debug_init_sdfs("sd:/", -1);
+    return sdcard_mounted;
+}
+
+size_t writeBufferToFile(const char* path, const uint8_t* buffer, size_t bufferSize)
+{
+    size_t ret;
+    if(!sdcard_mounted)
+    {
+        return 0;
+    }
+
+    FILE* f = fopen(path, "w");
+    if(!f)
+    {
+        return 0;
+    }
+
+    ret = fwrite(buffer, sizeof(char), bufferSize, f);
+
+    fclose(f);
+    return ret;
 }

src/menu/MenuEntries.cpp

@@ -20,6 +20,10 @@ MenuItemData gen1MenuEntries[] = {
         .title = "Gen 3 Transfer Info",
         .onConfirmAction = goToPokeTransporterGBRef
     },
+    {
+        .title = "Test SD Write",
+        .onConfirmAction = writeFileToSD
+    },
     {
         .title = "About",
         .onConfirmAction = goToAboutScene
@@ -45,6 +49,10 @@ MenuItemData gen2MenuEntries[] = {
         .title = "Gen 3 Transfer Info",
         .onConfirmAction = goToPokeTransporterGBRef
     },
+    {
+        .title = "Test SD Write",
+        .onConfirmAction = writeFileToSD
+    },
     {
         .title = "About",
         .onConfirmAction = goToAboutScene
@@ -74,6 +82,10 @@ MenuItemData gen2CrystalMenuEntries[] = {
         .title = "Gen 3 Transfer Info",
         .onConfirmAction = goToPokeTransporterGBRef
     },
+    {
+        .title = "Test SD Write",
+        .onConfirmAction = writeFileToSD
+    },
     {
         .title = "About",
         .onConfirmAction = goToAboutScene

src/menu/MenuFunctions.cpp

@@ -414,3 +414,29 @@ void gen2SetEventFlag(void* context, const void* param)
     tpakManager.setRAMEnabled(false);
     scene->showDialog(messageData);
 }
+
+void writeFileToSD(void* context, const void* param)
+{
+    MenuScene* scene = static_cast<MenuScene*>(context);
+
+    DialogData* msg = new DialogData{
+        .shouldDeleteWhenDone = true
+    };
+
+    if(sdcard_mounted)
+    {
+        const char* test = "Hello Phil 2!";
+
+        size_t ret = writeBufferToFile("sd:/helloworld.txt", reinterpret_cast<const uint8_t*>(test), strlen(test));
+        if(!ret)
+        {
+            setDialogDataText(*msg, "ERROR: Could not write to file sd:/helloworld.txt!");
+        }
+        else
+        {
+            setDialogDataText(*msg, "SUCCESS: Check the SD! sd:/helloworld.txt should exist!");
+        }
+    }
+
+    scene->showDialog(msg);
+}