Re-enable save system, fix header/version stamping, handle missing media

- Fixed the actual reason saving never worked on any platform: saveWrite()
  never stamped file->header/file->version before serializing, so every
  written save file had a zeroed magic header and failed its own
  validation on the next load. Confirmed via a manual write/load round
  trip that this alone fully explains "saving doesn't work."
- Re-enabled saveInit()/saveDispose() in engine.c (previously commented out
  under "Temporarily disable save code").
- Added SAVE.available + saveIsAvailable(), refreshed by every real
  save/load/delete attempt. saveInit() no longer treats an unreachable
  save medium as fatal to booting - it logs and continues, since a missing
  memory card/stick shouldn't prevent playing.
- Hardened PSP's saveInitPSP() to actually detect a missing memory stick
  (sceIoGetstat on ms0:/) instead of assuming success, and fixed
  single-level sceIoMkdir to build the full PSP/SAVEDATA directory chain.
- Added busy-retry (CARD_ERROR_BUSY) and a not-mounted guard to Dolphin's
  live savestreamdolphin.c path, extending the same handling already
  backported into savedolphin.c.
- Added a "Save" entry to the game menu wired to saveWrite(0), showing a
  clear message on success, on failure, and when saveIsAvailable() is false.

assets/locale/en_US.po

@@ -56,6 +56,10 @@ msgstr "Items"
 msgid "ui.game_menu.settings"
 msgstr "Settings"
 
+#: src/dusk/ui/frame/game/uigamemenu.c
+msgid "ui.game_menu.save"
+msgstr "Save"
+
 msgid "item.potion.name"
 msgstr "Potion"
 

assets/locale/es_MX.po

@@ -57,6 +57,10 @@ msgstr "Objetos"
 msgid "ui.game_menu.settings"
 msgstr "Configuración"
 
+#: src/dusk/ui/frame/game/uigamemenu.c
+msgid "ui.game_menu.save"
+msgstr "Guardar"
+
 #: src/dusk/rpg/item/item.json
 msgid "item.potion.name"
 msgstr "Poción"

assets/locale/jp_JP.po

@@ -57,6 +57,10 @@ msgstr "アイテム"
 msgid "ui.game_menu.settings"
 msgstr "設定"
 
+#: src/dusk/ui/frame/game/uigamemenu.c
+msgid "ui.game_menu.save"
+msgstr "セーブ"
+
 #: src/dusk/rpg/item/item.json
 msgid "item.potion.name"
 msgstr "ポーション"

src/dusk/engine/engine.c

@@ -37,7 +37,7 @@ errorret_t engineInit(const int32_t argc, const char_t **argv) {
   errorChain(systemInit());
   errorChain(inputInit());
   errorChain(assetInit());
-  // errorChain(saveInit());
+  errorChain(saveInit());
   errorChain(localeManagerInit());
   errorChain(displayInit());
   errorChain(uiInit());
@@ -88,7 +88,7 @@ errorret_t engineDispose(void) {
   errorChain(uiDispose());
   consoleDispose();
   errorChain(displayDispose());
-  // errorChain(saveDispose());
+  errorChain(saveDispose());
   errorChain(assetDispose());
 
   errorOk();

src/dusk/save/save.c

@@ -9,6 +9,7 @@
 #include "save/savestream.h"
 #include "util/memory.h"
 #include "assert/assert.h"
+#include "error/error.h"
 
 save_t SAVE;
 
@@ -16,12 +17,23 @@ errorret_t saveInit(void) {
   memoryZero(&SAVE, sizeof(save_t));
 
   #ifdef saveInitPlatform
-    errorChain(saveInitPlatform());
+    // A missing/unreachable save medium is expected, recoverable state,
+    // not a reason to fail booting the whole game - log it and carry on
+    // with SAVE.available false instead of chaining the error upward.
+    errorret_t result = saveInitPlatform();
+    SAVE.available = errorIsOk(result);
+    if(!SAVE.available) errorCatch(errorPrint(result));
+  #else
+    SAVE.available = false;
   #endif
 
   errorOk();
 }
 
+bool_t saveIsAvailable(void) {
+  return SAVE.available;
+}
+
 errorret_t saveDispose(void) {
   #ifdef saveDisposePlatform
     errorChain(saveDisposePlatform());
@@ -39,7 +51,9 @@ errorret_t saveLoad(const uint8_t slot) {
   memoryZero(&stream, sizeof(savestream_t));
 
   #ifdef saveStreamOpenReadPlatform
-    errorChain(saveStreamOpenReadPlatform(&stream, slot));
+    errorret_t openRet = saveStreamOpenReadPlatform(&stream, slot);
+    SAVE.available = errorIsOk(openRet);
+    errorChain(openRet);
   #endif
 
   if(!stream.found) errorOk();
@@ -62,12 +76,21 @@ errorret_t saveWrite(const uint8_t slot) {
   assertTrue(slot < SAVE_FILE_COUNT_MAX, "slot exceeds SAVE_FILE_COUNT_MAX");
 
   savefile_t *file = &SAVE.files[slot];
+  // These are metadata about the file itself, not game data - always stamp
+  // the current magic/version on every write rather than relying on
+  // whatever happened to already be in memory (zeroed at saveInit, or
+  // whatever version an old loaded file had), otherwise the written file
+  // fails its own header check the next time it's loaded.
+  memoryCopy(file->header, SAVE_FILE_HEADER, SAVE_FILE_HEADER_SIZE);
+  file->version = SAVE_FILE_VERSION;
 
   savestream_t stream;
   memoryZero(&stream, sizeof(savestream_t));
 
   #ifdef saveStreamOpenWritePlatform
-    errorChain(saveStreamOpenWritePlatform(&stream, slot));
+    errorret_t openRet = saveStreamOpenWritePlatform(&stream, slot);
+    SAVE.available = errorIsOk(openRet);
+    errorChain(openRet);
   #endif
 
   errorret_t ret = saveFileWrite(&stream, file);
@@ -90,7 +113,9 @@ errorret_t saveDelete(const uint8_t slot) {
   assertTrue(slot < SAVE_FILE_COUNT_MAX, "slot exceeds SAVE_FILE_COUNT_MAX");
 
   #ifdef saveDeletePlatform
-    errorChain(saveDeletePlatform(slot));
+    errorret_t deleteRet = saveDeletePlatform(slot);
+    SAVE.available = errorIsOk(deleteRet);
+    errorChain(deleteRet);
   #endif
 
   SAVE.files[slot].exists = false;

src/dusk/save/save.h

@@ -15,17 +15,39 @@ typedef struct {
   savefile_t files[SAVE_FILE_COUNT_MAX];
   /** Platform-specific save system state (paths, card handles, etc.). */
   saveplatform_t platform;
+  /**
+   * True if the save medium (memory card/stick/disk) was reachable the
+   * last time it was checked - at saveInit(), and refreshed by every
+   * subsequent saveLoad()/saveWrite() attempt. Starting the game with no
+   * card/stick inserted, or one being removed mid-session, are both
+   * expected conditions here, not fatal errors - see saveIsAvailable().
+   */
+  bool_t available;
 } save_t;
 
 extern save_t SAVE;
 
 /**
- * Initializes the save system.
+ * Initializes the save system. Never fails the way saveWrite/saveLoad can -
+ * if the platform's save medium isn't reachable (e.g. no memory card/stick
+ * inserted), that's logged and reflected in saveIsAvailable() rather than
+ * treated as fatal, since the game should still be playable without save
+ * support.
  *
- * @return An error code if initialization fails.
+ * @return An error code only for unexpected platform failures.
  */
 errorret_t saveInit(void);
 
+/**
+ * Checks whether the save medium was reachable as of the last save/load
+ * attempt (or saveInit(), if none has been attempted yet). Intended for UI
+ * to decide whether to offer saving/loading at all, or to explain why it
+ * isn't available right now - e.g. "No memory card inserted".
+ *
+ * @return true if the save medium was available last time it was checked.
+ */
+bool_t saveIsAvailable(void);
+
 /**
  * Disposes of the save system.
  *

src/dusk/ui/frame/game/uigamemenu.c

@@ -9,16 +9,48 @@
 #include "ui/frame/uiframe.h"
 #include "ui/frame/settings/uisettings.h"
 #include "ui/frame/backpack/uibackpack.h"
+#include "ui/rpg/textbox/uitextboxmain.h"
 #include "util/memory.h"
 #include "display/spritebatch/spritebatch.h"
 #include "display/screen/screen.h"
 #include "assert/assert.h"
 #include "locale/localemanager.h"
 #include "asset/loader/locale/assetlocaleloader.h"
+#include "save/save.h"
+#include "error/error.h"
+#include "util/string.h"
 
 #define UI_GAME_MENU_INDEX_CHARACTERS 0
 #define UI_GAME_MENU_INDEX_ITEMS 1
 #define UI_GAME_MENU_INDEX_SETTINGS 2
+#define UI_GAME_MENU_INDEX_SAVE 3
+
+// Only one save slot is exposed through this menu for now - there is no
+// slot-select UI yet, and SAVE_FILE_COUNT_MAX > 1 exists for later.
+#define UI_GAME_MENU_SAVE_SLOT 0
+
+static void uiGameMenuSave(void) {
+  if(!saveIsAvailable()) {
+    uiTextboxMainSetText("Can't save - no save device found.");
+    return;
+  }
+
+  errorret_t ret = saveWrite(UI_GAME_MENU_SAVE_SLOT);
+  if(errorIsNotOk(ret)) {
+    // Generously sized - stringFormat asserts (crashes) rather than
+    // truncating if the message doesn't fit, so this must comfortably fit
+    // the longest platform save-error message plus this prefix.
+    char_t msg[256];
+    stringFormat(
+      msg, sizeof(msg), "Save failed: %s", ret.state->message
+    );
+    errorCatch(ret);
+    uiTextboxMainSetText(msg);
+    return;
+  }
+
+  uiTextboxMainSetText("Game saved.");
+}
 
 uigamemenu_t UI_GAME_MENU;
 
@@ -29,6 +61,7 @@ void uiGameMenuSelected(
 ) {
   if(index == UI_GAME_MENU_INDEX_ITEMS) uiBackpackOpen();
   if(index == UI_GAME_MENU_INDEX_SETTINGS) uiSettingsOpen();
+  if(index == UI_GAME_MENU_INDEX_SAVE) uiGameMenuSave();
 }
 
 errorret_t uiGameMenuInit(void) {
@@ -55,6 +88,13 @@ errorret_t uiGameMenuInit(void) {
     UI_GAME_MENU.settingsLabel,
     UI_GAME_MENU_LABEL_MAX
   ));
+  errorChain(assetLocaleGetString(
+    &LOCALE.entry->data.locale,
+    "ui.game_menu.save",
+    0,
+    UI_GAME_MENU.saveLabel,
+    UI_GAME_MENU_LABEL_MAX
+  ));
 
   MENU_BEGIN(
     &UI_GAME_MENU.menu, UI_GAME_MENU.items, uiGameMenuSelected, NULL, NULL
@@ -62,6 +102,7 @@ errorret_t uiGameMenuInit(void) {
   MENU_BUTTON(UI_GAME_MENU.charactersLabel);
   MENU_BUTTON(UI_GAME_MENU.itemsLabel);
   MENU_BUTTON(UI_GAME_MENU.settingsLabel);
+  MENU_BUTTON(UI_GAME_MENU.saveLabel);
 
   MENU_END(UI_GAME_MENU.items, 1);
 

src/dusk/ui/frame/game/uigamemenu.h

@@ -9,7 +9,7 @@
 #include "error/error.h"
 #include "ui/widget/uimenu.h"
 
-#define UI_GAME_MENU_ITEM_COUNT 3
+#define UI_GAME_MENU_ITEM_COUNT 4
 #define UI_GAME_MENU_WIDTH 150.0f
 #define UI_GAME_MENU_LABEL_MAX 32
 
@@ -19,6 +19,7 @@ typedef struct {
   char_t charactersLabel[UI_GAME_MENU_LABEL_MAX];
   char_t itemsLabel[UI_GAME_MENU_LABEL_MAX];
   char_t settingsLabel[UI_GAME_MENU_LABEL_MAX];
+  char_t saveLabel[UI_GAME_MENU_LABEL_MAX];
 } uigamemenu_t;
 
 extern uigamemenu_t UI_GAME_MENU;

src/duskdolphin/save/savestreamdolphin.c

@@ -19,12 +19,20 @@ static void _saveStreamGetFileName(
 errorret_t saveStreamOpenReadDolphin(
   savestreamdolphin_t *p, bool_t *found, const uint8_t slot
 ) {
+  if(!SAVE.platform.mounted) {
+    *found = false;
+    errorThrow("No memory card mounted");
+  }
+
   char_t fileName[SAVE_DOLPHIN_FILE_NAME_MAX];
   _saveStreamGetFileName(fileName, SAVE_DOLPHIN_FILE_NAME_MAX, slot);
 
-  int32_t result = CARD_Open(
-    SAVE_DOLPHIN_CHANNEL, fileName, &p->cardFile
-  );
+  int32_t result;
+  do {
+    result = CARD_Open(
+      SAVE_DOLPHIN_CHANNEL, fileName, &p->cardFile
+    );
+  } while(result == CARD_ERROR_BUSY);
   if(result == CARD_ERROR_NOFILE) {
     *found = false;
     p->position = 0;
@@ -33,17 +41,19 @@ errorret_t saveStreamOpenReadDolphin(
   }
   if(result < 0) {
     *found = false;
-    errorThrow("Failed to open memory card file for slot %u (error %d)",
-      (uint32_t)slot, result
+    errorThrow("Failed to open memory card file for slot %u: %s (%d)",
+      (uint32_t)slot, saveCardErrorStringDolphin(result), result
     );
   }
 
-  result = CARD_Read(&p->cardFile, p->buffer, SAVE_DOLPHIN_SECTOR_SIZE, 0);
+  do {
+    result = CARD_Read(&p->cardFile, p->buffer, SAVE_DOLPHIN_SECTOR_SIZE, 0);
+  } while(result == CARD_ERROR_BUSY);
   CARD_Close(&p->cardFile);
   if(result < 0) {
     *found = false;
-    errorThrow("Failed to read memory card data for slot %u (error %d)",
-      (uint32_t)slot, result
+    errorThrow("Failed to read memory card data for slot %u: %s (%d)",
+      (uint32_t)slot, saveCardErrorStringDolphin(result), result
     );
   }
 
@@ -57,6 +67,8 @@ errorret_t saveStreamOpenReadDolphin(
 errorret_t saveStreamOpenWriteDolphin(
   savestreamdolphin_t *p, const uint8_t slot
 ) {
+  if(!SAVE.platform.mounted) errorThrow("No memory card mounted");
+
   memoryZero(p->buffer, SAVE_DOLPHIN_SECTOR_SIZE);
   p->position = 0;
   p->writing = true;
@@ -70,14 +82,21 @@ void saveStreamCloseDolphin(savestreamdolphin_t *p) {
   char_t fileName[SAVE_DOLPHIN_FILE_NAME_MAX];
   _saveStreamGetFileName(fileName, SAVE_DOLPHIN_FILE_NAME_MAX, p->slot);
 
-  int32_t result = CARD_Open(SAVE_DOLPHIN_CHANNEL, fileName, &p->cardFile);
+  int32_t result;
+  do {
+    result = CARD_Open(SAVE_DOLPHIN_CHANNEL, fileName, &p->cardFile);
+  } while(result == CARD_ERROR_BUSY);
   if(result == CARD_ERROR_NOFILE) {
-    CARD_Create(
-      SAVE_DOLPHIN_CHANNEL, fileName, SAVE_DOLPHIN_SECTOR_SIZE, &p->cardFile
-    );
+    do {
+      result = CARD_Create(
+        SAVE_DOLPHIN_CHANNEL, fileName, SAVE_DOLPHIN_SECTOR_SIZE, &p->cardFile
+      );
+    } while(result == CARD_ERROR_BUSY);
   }
 
-  CARD_Write(&p->cardFile, p->buffer, SAVE_DOLPHIN_SECTOR_SIZE, 0);
+  do {
+    result = CARD_Write(&p->cardFile, p->buffer, SAVE_DOLPHIN_SECTOR_SIZE, 0);
+  } while(result == CARD_ERROR_BUSY);
   CARD_Close(&p->cardFile);
 }
 

src/duskpsp/save/savepsp.c

@@ -7,7 +7,18 @@
 
 #include "save/save.h"
 
+void savePSPEnsureBaseDirs(void) {
+  sceIoMkdir(SAVE_PSP_BASE_DIR, 0777);
+  sceIoMkdir(SAVE_PSP_SAVEDATA_DIR, 0777);
+}
+
 errorret_t saveInitPSP(void) {
+  SceIoStat stat;
+  if(sceIoGetstat(SAVE_PSP_ROOT, &stat) < 0) {
+    errorThrow("No memory stick detected");
+  }
+
+  savePSPEnsureBaseDirs();
   errorOk();
 }
 
@@ -40,6 +51,7 @@ errorret_t saveLoadPSP(const uint8_t slot, savefile_t *file) {
 }
 
 errorret_t saveWritePSP(const uint8_t slot, const savefile_t *file) {
+  savePSPEnsureBaseDirs();
   char_t dir[SAVE_PSP_PATH_MAX];
   snprintf(dir, SAVE_PSP_PATH_MAX, SAVE_PSP_DIR_FORMAT,
     SAVE_PSP_TITLE_ID, (uint32_t)slot

src/duskpsp/save/savepsp.h

@@ -11,6 +11,9 @@
 #include <pspiofilemgr.h>
 
 #define SAVE_PSP_PATH_MAX 256
+#define SAVE_PSP_ROOT "ms0:/"
+#define SAVE_PSP_BASE_DIR "ms0:/PSP"
+#define SAVE_PSP_SAVEDATA_DIR "ms0:/PSP/SAVEDATA"
 #define SAVE_PSP_FILE_FORMAT "ms0:/PSP/SAVEDATA/%s%02u/save.dat"
 #define SAVE_PSP_DIR_FORMAT "ms0:/PSP/SAVEDATA/%s%02u"
 
@@ -23,9 +26,14 @@ typedef struct {
 } savepsp_t;
 
 /**
- * Initializes the save system on PSP.
+ * Initializes the save system on PSP. Confirms the memory stick is
+ * actually reachable (sceIoGetstat on SAVE_PSP_ROOT) rather than assuming
+ * so, since raw sceIo calls otherwise only fail once something tries to
+ * touch the filesystem - and ensures the PSP/SAVEDATA directory tree
+ * exists (SAVE_PSP_BASE_DIR then SAVE_PSP_SAVEDATA_DIR, since sceIoMkdir
+ * only creates one level at a time).
  *
- * @return An error code if initialization fails.
+ * @return An error code if no memory stick is reachable.
  */
 errorret_t saveInitPSP(void);
 
@@ -61,3 +69,12 @@ errorret_t saveWritePSP(const uint8_t slot, const savefile_t *file);
  * @return An error code if the delete fails.
  */
 errorret_t saveDeletePSP(const uint8_t slot);
+
+/**
+ * Ensures SAVE_PSP_BASE_DIR and SAVE_PSP_SAVEDATA_DIR both exist, creating
+ * whichever are missing. sceIoMkdir only creates one directory level at a
+ * time, so this must run before creating any per-slot save directory
+ * beneath SAVE_PSP_SAVEDATA_DIR. Safe to call repeatedly - an
+ * already-exists result is not an error.
+ */
+void savePSPEnsureBaseDirs(void);

src/duskpsp/save/savestreampsp.c

@@ -22,6 +22,7 @@ errorret_t saveStreamOpenReadPSP(
 }
 
 errorret_t saveStreamOpenWritePSP(savestreampsp_t *p, const uint8_t slot) {
+  savePSPEnsureBaseDirs();
   char_t dir[SAVE_PSP_PATH_MAX];
   snprintf(dir, SAVE_PSP_PATH_MAX, SAVE_PSP_DIR_FORMAT,
     SAVE_PSP_TITLE_ID, (uint32_t)slot