romfs: slightly improve interface.

code_templates/sd_romfs_dumper.c

@@ -99,14 +99,16 @@ static void read_thread_func(void *arg)
         goto end;
     }
 
-    u64 file_table_offset = 0;
-    u64 file_table_size = shared_data->romfs_ctx->file_table_size;
     RomFileSystemFileEntry *file_entry = NULL;
 
     char path[FS_MAX_PATH] = {0};
     sprintf(path, "sdmc:/romfs");
 
-    while(file_table_offset < file_table_size)
+    /* Reset current file table offset. */
+    romfsResetFileTableOffset(shared_data->romfs_ctx);
+
+    /* Loop through all file entries. */
+    while(romfsCanMoveToNextFileEntry(shared_data->romfs_ctx))
     {
         /* Check if the transfer has been cancelled by the user. */
         if (shared_data->transfer_cancelled)
@@ -130,7 +132,7 @@ static void read_thread_func(void *arg)
         }
 
         /* Retrieve RomFS file entry information. */
-        shared_data->read_error = (!(file_entry = romfsGetFileEntryByOffset(shared_data->romfs_ctx, file_table_offset)) || \
+        shared_data->read_error = (!(file_entry = romfsGetCurrentFileEntry(shared_data->romfs_ctx)) || \
                                     !romfsGeneratePathFromFileEntry(shared_data->romfs_ctx, file_entry, path + 11, FS_MAX_PATH - 11, RomFileSystemPathIllegalCharReplaceType_KeepAsciiCharsOnly));
         if (shared_data->read_error)
         {
@@ -197,7 +199,13 @@ static void read_thread_func(void *arg)
 
         if (shared_data->read_error || shared_data->write_error || shared_data->transfer_cancelled) break;
 
-        file_table_offset += ALIGN_UP(sizeof(RomFileSystemFileEntry) + file_entry->name_length, 4);
+        /* Move to the next file entry. */
+        shared_data->read_error = !romfsMoveToNextFileEntry(shared_data->romfs_ctx);
+        if (shared_data->read_error)
+        {
+            condvarWakeAll(&g_writeCondvar);
+            break;
+        }
     }
 
     /* Wait until the previous file data chunk has been written. */

code_templates/system_title_dumper.c

@@ -160,7 +160,6 @@ static void dumpRomFs(TitleInfo *info, NcaFsSectionContext *nca_fs_ctx)
 {
     if (!buf || !info || !nca_fs_ctx) return;
 
-    u64 romfs_file_table_offset = 0;
     RomFileSystemContext romfs_ctx = {0};
     RomFileSystemFileEntry *romfs_file_entry = NULL;
 
@@ -178,12 +177,12 @@ static void dumpRomFs(TitleInfo *info, NcaFsSectionContext *nca_fs_ctx)
     utilsCreateDirectoryTree(path, true);
     path_len = strlen(path);
 
-    while(romfs_file_table_offset < romfs_ctx.file_table_size)
+    while(romfsCanMoveToNextFileEntry(&romfs_ctx))
     {
-        if (!(romfs_file_entry = romfsGetFileEntryByOffset(&romfs_ctx, romfs_file_table_offset)) || \
+        if (!(romfs_file_entry = romfsGetCurrentFileEntry(&romfs_ctx)) || \
             !romfsGeneratePathFromFileEntry(&romfs_ctx, romfs_file_entry, path + path_len, sizeof(path) - path_len, RomFileSystemPathIllegalCharReplaceType_KeepAsciiCharsOnly))
         {
-            consolePrint("romfs get entry / generate path failed for 0x%lX!\n", romfs_file_table_offset);
+            consolePrint("romfs get entry / generate path failed for 0x%lX!\n", romfs_ctx.cur_file_offset);
             goto end;
         }
 
@@ -215,7 +214,11 @@ static void dumpRomFs(TitleInfo *info, NcaFsSectionContext *nca_fs_ctx)
         fclose(filefd);
         filefd = NULL;
 
-        romfs_file_table_offset += ALIGN_UP(sizeof(RomFileSystemFileEntry) + romfs_file_entry->name_length, 4);
+        if (!romfsMoveToNextFileEntry(&romfs_ctx))
+        {
+            consolePrint("failed to move to next file entry!\n");
+            goto end;
+        }
     }
 
     consolePrint("romfs dump complete\n");

code_templates/usb_romfs_dumper.c

@@ -100,12 +100,14 @@ static void read_thread_func(void *arg)
         goto end;
     }
 
-    u64 file_table_offset = 0;
-    u64 file_table_size = shared_data->romfs_ctx->file_table_size;
     RomFileSystemFileEntry *file_entry = NULL;
     char path[FS_MAX_PATH] = {0};
 
-    while(file_table_offset < file_table_size)
+    /* Reset current file table offset. */
+    romfsResetFileTableOffset(shared_data->romfs_ctx);
+
+    /* Loop through all file entries. */
+    while(romfsCanMoveToNextFileEntry(shared_data->romfs_ctx))
     {
         /* Check if the transfer has been cancelled by the user */
         if (shared_data->transfer_cancelled)
@@ -115,7 +117,7 @@ static void read_thread_func(void *arg)
         }
 
         /* Retrieve RomFS file entry information */
-        shared_data->read_error = (!(file_entry = romfsGetFileEntryByOffset(shared_data->romfs_ctx, file_table_offset)) || \
+        shared_data->read_error = (!(file_entry = romfsGetCurrentFileEntry(shared_data->romfs_ctx)) || \
                                     !romfsGeneratePathFromFileEntry(shared_data->romfs_ctx, file_entry, path, FS_MAX_PATH, RomFileSystemPathIllegalCharReplaceType_IllegalFsChars));
         if (shared_data->read_error)
         {
@@ -178,7 +180,13 @@ static void read_thread_func(void *arg)
 
         if (shared_data->read_error || shared_data->write_error || shared_data->transfer_cancelled) break;
 
-        file_table_offset += ALIGN_UP(sizeof(RomFileSystemFileEntry) + file_entry->name_length, 4);
+        /* Move to the next file entry. */
+        shared_data->read_error = !romfsMoveToNextFileEntry(shared_data->romfs_ctx);
+        if (shared_data->read_error)
+        {
+            condvarWakeAll(&g_writeCondvar);
+            break;
+        }
     }
 
     free(buf);

include/core/nxdt_utils.h

@@ -109,7 +109,7 @@ void utilsJoinThread(Thread *thread);
 __attribute__((format(printf, 3, 4))) bool utilsAppendFormattedStringToBuffer(char **dst, size_t *dst_size, const char *fmt, ...);
 
 /// Replaces illegal FAT characters in the provided UTF-8 string with underscores.
-/// If 'ascii_only' is set to true, all codepoints outside the (0x20,0x7E] range will also be replaced with underscores.
+/// If 'ascii_only' is set to true, all codepoints outside the [0x20,0x7F) range will also be replaced with underscores.
 /// Replacements are performed on a per-codepoint basis, which means the string length can be reduced by this function.
 void utilsReplaceIllegalCharacters(char *str, bool ascii_only);
 

include/core/romfs.h

@@ -30,10 +30,12 @@
 extern "C" {
 #endif
 
-#define ROMFS_OLD_HEADER_SIZE   0x28
+#define ROMFS_OLD_HEADER_SIZE       0x28
-#define ROMFS_HEADER_SIZE       0x50
+#define ROMFS_HEADER_SIZE           0x50
 
-#define ROMFS_VOID_ENTRY        0xFFFFFFFF
+#define ROMFS_VOID_ENTRY            UINT32_MAX
+
+#define ROMFS_TABLE_ENTRY_ALIGNMENT 0x4
 
 /// Header used by NCA0 RomFS sections.
 typedef struct {
@@ -80,28 +82,28 @@ typedef struct {
 
 NXDT_ASSERT(RomFileSystemHeader, ROMFS_HEADER_SIZE);
 
-/// Directory entry. Always aligned to a 4-byte boundary past the directory name.
+/// Directory entry. Always aligned to a ROMFS_TABLE_ENTRY_ALIGNMENT boundary past the directory name.
 typedef struct {
     u32 parent_offset;      ///< Parent directory offset.
-    u32 next_offset;        ///< Next sibling directory offset.
+    u32 next_offset;        ///< Next sibling directory offset. May be set to ROMFS_VOID_ENTRY if there are no other directory entries at this level.
-    u32 directory_offset;   ///< First child directory offset.
+    u32 directory_offset;   ///< First child directory offset. May be set to ROMFS_VOID_ENTRY if there are no child directories entries.
-    u32 file_offset;        ///< First child file offset.
+    u32 file_offset;        ///< First child file offset. May be set to ROMFS_VOID_ENTRY if there are no child file entries.
     u32 bucket_offset;      ///< Directory bucket offset.
     u32 name_length;        ///< Name length.
-    char name[];            ///< Name (UTF-8).
+    char name[];            ///< Name (UTF-8, may not be NULL terminated depending on the whole entry alignment).
 } RomFileSystemDirectoryEntry;
 
 NXDT_ASSERT(RomFileSystemDirectoryEntry, 0x18);
 
-/// Directory entry. Always aligned to a 4-byte boundary past the file name.
+/// Directory entry. Always aligned to a ROMFS_TABLE_ENTRY_ALIGNMENT boundary past the file name.
 typedef struct {
     u32 parent_offset;      ///< Parent directory offset.
-    u32 next_offset;        ///< Next sibling file offset.
+    u32 next_offset;        ///< Next sibling file offset. May be set to ROMFS_VOID_ENTRY if there are no other file entries at this level.
     u64 offset;             ///< File data offset.
     u64 size;               ///< File data size.
     u32 bucket_offset;      ///< File bucket offset.
     u32 name_length;        ///< Name length.
-    char name[];            ///< Name (UTF-8).
+    char name[];            ///< Name (UTF-8, may not be NULL terminated depending on the whole entry alignment).
 } RomFileSystemFileEntry;
 
 NXDT_ASSERT(RomFileSystemFileEntry, 0x20);
@@ -118,7 +120,8 @@ typedef struct {
     u64 file_table_size;                    ///< RomFS file entries table size.
     RomFileSystemFileEntry *file_table;     ///< RomFS file entries table.
     u64 body_offset;                        ///< RomFS file data body offset (relative to the start of the RomFS).
-    u32 cur_dir_offset;                     ///< Current RomFS directory offset (relative to the start of the directory entries table). Used for RomFS browsing.
+    u64 cur_dir_offset;                     ///< Current RomFS directory offset (relative to the start of the directory entries table). Used for RomFS browsing.
+    u64 cur_file_offset;                    ///< Current RomFS file offset (relative to the start of the file entries table). Used for RomFS browsing.
 } RomFileSystemContext;
 
 typedef struct {
@@ -173,8 +176,7 @@ bool romfsGeneratePathFromFileEntry(RomFileSystemContext *ctx, RomFileSystemFile
 /// Use the romfsWriteFileEntryPatchToMemoryBuffer() wrapper to write patch data generated by this function.
 bool romfsGenerateFileEntryPatch(RomFileSystemContext *ctx, RomFileSystemFileEntry *file_entry, const void *data, u64 data_size, u64 data_offset, RomFileSystemFileEntryPatch *out);
 
-/// Miscellaneous functions.
+/// Resets a previously initialized RomFileSystemContext.
-
 NX_INLINE void romfsFreeContext(RomFileSystemContext *ctx)
 {
     if (!ctx) return;
@@ -185,22 +187,93 @@ NX_INLINE void romfsFreeContext(RomFileSystemContext *ctx)
     memset(ctx, 0, sizeof(RomFileSystemContext));
 }
 
-NX_INLINE RomFileSystemDirectoryEntry *romfsGetDirectoryEntryByOffset(RomFileSystemContext *ctx, u32 dir_entry_offset)
+/// Functions to reset the current directory/file entry offset.
+NX_INLINE void romfsResetDirectoryTableOffset(RomFileSystemContext *ctx)
 {
-    if (!ctx || !ctx->dir_table || (dir_entry_offset + sizeof(RomFileSystemDirectoryEntry)) > ctx->dir_table_size) return NULL;
+    if (ctx) ctx->cur_dir_offset = 0;
-    return (RomFileSystemDirectoryEntry*)((u8*)ctx->dir_table + dir_entry_offset);
 }
 
-NX_INLINE RomFileSystemFileEntry *romfsGetFileEntryByOffset(RomFileSystemContext *ctx, u32 file_entry_offset)
+NX_INLINE void romfsResetFileTableOffset(RomFileSystemContext *ctx)
 {
-    if (!ctx || !ctx->file_table || (file_entry_offset + sizeof(RomFileSystemFileEntry)) > ctx->file_table_size) return NULL;
+    if (ctx) ctx->cur_file_offset = 0;
-    return (RomFileSystemFileEntry*)((u8*)ctx->file_table + file_entry_offset);
 }
 
+/// Checks if the provided RomFileSystemContext is valid.
+NX_INLINE bool romfsIsValidContext(RomFileSystemContext *ctx)
+{
+    return (ctx && ncaStorageIsValidContext(ctx->default_storage_ctx) && ctx->size && ctx->dir_table_size && ctx->dir_table && ctx->file_table_size && ctx->file_table && \
+            ctx->body_offset >= ctx->header.old_format.header_size && ctx->body_offset < ctx->size);
+}
+
+/// Functions to retrieve a directory/file entry.
+NX_INLINE void *romfsGetEntryByOffset(RomFileSystemContext *ctx, void *entry_table, u64 entry_table_size, u64 entry_size, u64 entry_offset)
+{
+    if (!romfsIsValidContext(ctx) || !entry_table || !entry_table_size || !entry_size || (entry_offset + entry_size) > entry_table_size) return NULL;
+    return ((u8*)entry_table + entry_offset);
+}
+
+NX_INLINE RomFileSystemDirectoryEntry *romfsGetDirectoryEntryByOffset(RomFileSystemContext *ctx, u64 dir_entry_offset)
+{
+    return (ctx ? (RomFileSystemDirectoryEntry*)romfsGetEntryByOffset(ctx, ctx->dir_table, ctx->dir_table_size, sizeof(RomFileSystemDirectoryEntry), dir_entry_offset) : NULL);
+}
+
+NX_INLINE RomFileSystemDirectoryEntry *romfsGetCurrentDirectoryEntry(RomFileSystemContext *ctx)
+{
+    return (ctx ? romfsGetDirectoryEntryByOffset(ctx, ctx->cur_dir_offset) : NULL);
+}
+
+NX_INLINE RomFileSystemFileEntry *romfsGetFileEntryByOffset(RomFileSystemContext *ctx, u64 file_entry_offset)
+{
+    return (ctx ? (RomFileSystemFileEntry*)romfsGetEntryByOffset(ctx, ctx->file_table, ctx->file_table_size, sizeof(RomFileSystemFileEntry), file_entry_offset) : NULL);
+}
+
+NX_INLINE RomFileSystemFileEntry *romfsGetCurrentFileEntry(RomFileSystemContext *ctx)
+{
+    return (ctx ? romfsGetFileEntryByOffset(ctx, ctx->cur_file_offset) : NULL);
+}
+
+/// Functions to check if it's possible to move to the next directory/file entry based on the current directory/file entry offset.
+NX_INLINE bool romfsCanMoveToNextEntry(RomFileSystemContext *ctx, void *entry_table, u64 entry_table_size, u64 entry_size, u64 entry_offset)
+{
+    if (!romfsIsValidContext(ctx) || !entry_table || !entry_table_size || entry_size < 4 || (entry_offset + entry_size) > entry_table_size) return false;
+    u32 name_length = *((u32*)((u8*)entry_table + entry_offset + entry_size - 4));
+    return ((entry_offset + ALIGN_UP(entry_size + name_length, ROMFS_TABLE_ENTRY_ALIGNMENT)) <= entry_table_size);
+}
+
+NX_INLINE bool romfsCanMoveToNextDirectoryEntry(RomFileSystemContext *ctx)
+{
+    return (ctx ? romfsCanMoveToNextEntry(ctx, ctx->dir_table, ctx->dir_table_size, sizeof(RomFileSystemDirectoryEntry), ctx->cur_dir_offset) : false);
+}
+
+NX_INLINE bool romfsCanMoveToNextFileEntry(RomFileSystemContext *ctx)
+{
+    return (ctx ? romfsCanMoveToNextEntry(ctx, ctx->file_table, ctx->file_table_size, sizeof(RomFileSystemFileEntry), ctx->cur_file_offset) : false);
+}
+
+/// Functions to update the current directory/file entry offset to make it point to the next directory/file entry.
+NX_INLINE bool romfsMoveToNextEntry(RomFileSystemContext *ctx, void *entry_table, u64 entry_table_size, u64 entry_size, u64 *entry_offset)
+{
+    if (!romfsIsValidContext(ctx) || !entry_table || !entry_table_size || entry_size < 4 || !entry_offset || (*entry_offset + entry_size) > entry_table_size) return false;
+    u32 name_length = *((u32*)((u8*)entry_table + *entry_offset + entry_size - 4));
+    *entry_offset += ALIGN_UP(entry_size + name_length, ROMFS_TABLE_ENTRY_ALIGNMENT);
+    return true;
+}
+
+NX_INLINE bool romfsMoveToNextDirectoryEntry(RomFileSystemContext *ctx)
+{
+    return (ctx ? romfsMoveToNextEntry(ctx, ctx->dir_table, ctx->dir_table_size, sizeof(RomFileSystemDirectoryEntry), &(ctx->cur_dir_offset)) : false);
+}
+
+NX_INLINE bool romfsMoveToNextFileEntry(RomFileSystemContext *ctx)
+{
+    return (ctx ? romfsMoveToNextEntry(ctx, ctx->file_table, ctx->file_table_size, sizeof(RomFileSystemFileEntry), &(ctx->cur_file_offset)) : false);
+}
+
+/// NCA patch management functions.
 NX_INLINE void romfsWriteFileEntryPatchToMemoryBuffer(RomFileSystemContext *ctx, RomFileSystemFileEntryPatch *patch, void *buf, u64 buf_size, u64 buf_offset)
 {
-    if (!ctx || ctx->is_patch || !ncaStorageIsValidContext(ctx->default_storage_ctx) || ctx->default_storage_ctx->base_storage_type != NcaStorageBaseStorageType_Regular || !patch || \
+    if (!romfsIsValidContext(ctx) || ctx->is_patch || ctx->default_storage_ctx->base_storage_type != NcaStorageBaseStorageType_Regular || !patch || \
-        (!patch->use_old_format_patch && ctx->default_storage_ctx->nca_fs_ctx->section_type == NcaFsSectionType_Nca0RomFs) || \
+        (!patch->use_old_format_patch && ctx->default_storage_ctx->nca_fs_ctx->section_type != NcaFsSectionType_RomFs) || \
         (patch->use_old_format_patch && ctx->default_storage_ctx->nca_fs_ctx->section_type != NcaFsSectionType_Nca0RomFs)) return;
 
     NcaContext *nca_ctx = (NcaContext*)ctx->default_storage_ctx->nca_fs_ctx->nca_ctx;

source/core/romfs.c

@@ -182,7 +182,7 @@ end:
 
 bool romfsReadFileSystemData(RomFileSystemContext *ctx, void *out, u64 read_size, u64 offset)
 {
-    if (!ctx || !ncaStorageIsValidContext(ctx->default_storage_ctx) || !ctx->size || !out || !read_size || (offset + read_size) > ctx->size)
+    if (!romfsIsValidContext(ctx) || !out || !read_size || (offset + read_size) > ctx->size)
     {
         LOG_MSG("Invalid parameters!");
         return false;
@@ -200,7 +200,8 @@ bool romfsReadFileSystemData(RomFileSystemContext *ctx, void *out, u64 read_size
 
 bool romfsReadFileEntryData(RomFileSystemContext *ctx, RomFileSystemFileEntry *file_entry, void *out, u64 read_size, u64 offset)
 {
-    if (!ctx || !ctx->body_offset || !file_entry || !file_entry->size || (file_entry->offset + file_entry->size) > ctx->size || !out || !read_size || (offset + read_size) > file_entry->size)
+    if (!romfsIsValidContext(ctx) || !file_entry || !file_entry->size || (file_entry->offset + file_entry->size) > ctx->size || !out || !read_size || \
+        (offset + read_size) > file_entry->size)
     {
         LOG_MSG("Invalid parameters!");
         return false;
@@ -218,75 +219,120 @@ bool romfsReadFileEntryData(RomFileSystemContext *ctx, RomFileSystemFileEntry *f
 
 bool romfsGetTotalDataSize(RomFileSystemContext *ctx, u64 *out_size)
 {
-    if (!ctx || !ctx->file_table_size || !ctx->file_table || !out_size)
+    if (!romfsIsValidContext(ctx) || !out_size)
     {
         LOG_MSG("Invalid parameters!");
         return false;
     }
 
-    u64 offset = 0, total_size = 0;
     RomFileSystemFileEntry *file_entry = NULL;
+    u64 total_size = 0;
+    bool success = false;
 
-    while(offset < ctx->file_table_size)
+    /* Reset current file table offset. */
+    romfsResetFileTableOffset(ctx);
+
+    /* Loop through all file entries. */
+    while(romfsCanMoveToNextFileEntry(ctx))
     {
-        if (!(file_entry = romfsGetFileEntryByOffset(ctx, offset)))
+        /* Get current file entry. */
+        if (!(file_entry = romfsGetCurrentFileEntry(ctx)))
         {
-            LOG_MSG("Failed to retrieve file entry!");
+            LOG_MSG("Failed to retrieve current file entry! (0x%lX, 0x%lX).", ctx->cur_file_offset, ctx->file_table_size);
-            return false;
+            goto end;
         }
 
+        /* Update total data size. */
         total_size += file_entry->size;
-        offset += ALIGN_UP(sizeof(RomFileSystemFileEntry) + file_entry->name_length, 4);
+
+        /* Move to the next file entry. */
+        if (!romfsMoveToNextFileEntry(ctx))
+        {
+            LOG_MSG("Failed to move to the next file entry! (0x%lX, 0x%lX).", ctx->cur_file_offset, ctx->file_table_size);
+            goto end;
+        }
     }
 
+    /* Update output values. */
     *out_size = total_size;
+    success = true;
 
-    return true;
+end:
+    /* Reset current file table offset. */
+    romfsResetFileTableOffset(ctx);
+
+    return success;
 }
 
 bool romfsGetDirectoryDataSize(RomFileSystemContext *ctx, RomFileSystemDirectoryEntry *dir_entry, u64 *out_size)
 {
-    if (!ctx || !ctx->dir_table_size || !ctx->dir_table || !ctx->file_table_size || !ctx->file_table || !dir_entry || (dir_entry->file_offset == ROMFS_VOID_ENTRY && \
+    if (!romfsIsValidContext(ctx) || !dir_entry || !out_size)
-        dir_entry->directory_offset == ROMFS_VOID_ENTRY) || !out_size)
     {
         LOG_MSG("Invalid parameters!");
         return false;
     }
 
-    u64 total_size = 0, child_dir_size = 0;
+    /* Short-circuit: check if we're dealing with an empty directory. */
-    u32 cur_file_offset = 0, cur_dir_offset = 0;
+    if (dir_entry->file_offset == ROMFS_VOID_ENTRY && dir_entry->directory_offset == ROMFS_VOID_ENTRY)
+    {
+        *out_size = 0;
+        return true;
+    }
+
     RomFileSystemFileEntry *cur_file_entry = NULL;
     RomFileSystemDirectoryEntry *cur_dir_entry = NULL;
+    u64 total_size = 0, cur_entry_offset = 0, child_dir_size = 0;
+    bool success = false;
 
-    cur_file_offset = dir_entry->file_offset;
+    /* Loop through the child file entries' linked list. */
-    while(cur_file_offset != ROMFS_VOID_ENTRY)
+    cur_entry_offset = dir_entry->file_offset;
+    while(cur_entry_offset != ROMFS_VOID_ENTRY)
     {
-        if (!(cur_file_entry = romfsGetFileEntryByOffset(ctx, cur_file_offset)))
+        /* Get current file entry. */
+        if (!(cur_file_entry = romfsGetFileEntryByOffset(ctx, cur_entry_offset)))
         {
-            LOG_MSG("Failed to retrieve file entry!");
+            LOG_MSG("Failed to retrieve file entry! (0x%lX, 0x%lX).", cur_entry_offset, ctx->file_table_size);
-            return false;
+            goto end;
         }
 
+        /* Update total data size. */
         total_size += cur_file_entry->size;
-        cur_file_offset = cur_file_entry->next_offset;
+
+        /* Update current file entry offset. */
+        cur_entry_offset = cur_file_entry->next_offset;
     }
 
-    cur_dir_offset = dir_entry->directory_offset;
+    /* Loop through the child directory entries' linked list. */
-    while(cur_dir_offset != ROMFS_VOID_ENTRY)
+    cur_entry_offset = dir_entry->directory_offset;
+    while(cur_entry_offset != ROMFS_VOID_ENTRY)
     {
-        if (!(cur_dir_entry = romfsGetDirectoryEntryByOffset(ctx, cur_dir_offset)) || !romfsGetDirectoryDataSize(ctx, cur_dir_entry, &child_dir_size))
+        /* Get current directory entry. */
+        if (!(cur_dir_entry = romfsGetDirectoryEntryByOffset(ctx, cur_entry_offset)))
         {
-            LOG_MSG("Failed to retrieve directory entry/size!");
+            LOG_MSG("Failed to retrieve directory entry! (0x%lX, 0x%lX).", cur_entry_offset, ctx->dir_table_size);
-            return false;
+            goto end;
         }
 
+        /* Calculate directory size. */
+        if (!romfsGetDirectoryDataSize(ctx, cur_dir_entry, &child_dir_size))
+        {
+            LOG_MSG("Failed to get size for directory entry! (0x%lX, 0x%lX).", cur_entry_offset, ctx->dir_table_size);
+            goto end;
+        }
+
+        /* Update total data size. */
         total_size += child_dir_size;
-        cur_dir_offset = cur_dir_entry->next_offset;
+
+        /* Update current directory entry offset. */
+        cur_entry_offset = cur_dir_entry->next_offset;
     }
 
+    /* Update output values. */
     *out_size = total_size;
+    success = true;
 
-    return true;
+end:
+    return success;
 }
 
 RomFileSystemDirectoryEntry *romfsGetDirectoryEntryByPath(RomFileSystemContext *ctx, const char *path)
@@ -295,22 +341,27 @@ RomFileSystemDirectoryEntry *romfsGetDirectoryEntryByPath(RomFileSystemContext *
     char *path_dup = NULL, *pch = NULL, *state = NULL;
     RomFileSystemDirectoryEntry *dir_entry = NULL;
 
-    if (!ctx || !ctx->dir_table || !ctx->dir_table_size || !path || *path != '/' || !(path_len = strlen(path)) || !(dir_entry = romfsGetDirectoryEntryByOffset(ctx, 0)))
+    if (!romfsIsValidContext(ctx) || !path || *path != '/' || !(dir_entry = romfsGetDirectoryEntryByOffset(ctx, 0)))
     {
         LOG_MSG("Invalid parameters!");
         return NULL;
     }
 
-    /* Check if the root directory was requested. */
+    /* Retrieve path length. */
+    path_len = strlen(path);
+
+    /* Short-circuit: check if the root directory was requested. */
     if (path_len == 1) return dir_entry;
 
     /* Duplicate path to avoid problems with strtok_r(). */
     if (!(path_dup = strdup(path)))
     {
         LOG_MSG("Unable to duplicate input path! (\"%s\").", path);
-        return NULL;
+        dir_entry = NULL;
+        goto end;
     }
 
+    /* Tokenize duplicated path using path separators. */
     pch = strtok_r(path_dup, "/", &state);
     if (!pch)
     {
@@ -319,14 +370,17 @@ RomFileSystemDirectoryEntry *romfsGetDirectoryEntryByPath(RomFileSystemContext *
         goto end;
     }
 
+    /* Loop through all path elements. */
     while(pch)
     {
+        /* Get child directory entry using the current token. */
         if (!(dir_entry = romfsGetChildDirectoryEntryByName(ctx, dir_entry, pch)))
         {
             LOG_MSG("Failed to retrieve directory entry by name for \"%s\"! (\"%s\").", pch, path);
             break;
         }
 
+        /* Move onto the next token. */
         pch = strtok_r(NULL, "/", &state);
     }
 
@@ -345,20 +399,23 @@ RomFileSystemFileEntry *romfsGetFileEntryByPath(RomFileSystemContext *ctx, const
     RomFileSystemDirectoryEntry *dir_entry = NULL;
     NcaContext *nca_ctx = NULL;
 
-    if (!ctx || !ctx->file_table || !ctx->file_table_size || !ncaStorageIsValidContext(ctx->default_storage_ctx) || \
+    if (!romfsIsValidContext(ctx) || !(nca_ctx = (NcaContext*)ctx->default_storage_ctx->nca_fs_ctx->nca_ctx) || !path || *path != '/')
-        !(nca_ctx = (NcaContext*)ctx->default_storage_ctx->nca_fs_ctx->nca_ctx) || !path || *path != '/' || (path_len = strlen(path)) <= 1)
     {
         LOG_MSG("Invalid parameters!");
         return NULL;
     }
 
+    /* Retrieve path length. */
+    path_len = strlen(path);
+
+    /* Retrieve NCA content type. */
     content_type = nca_ctx->content_type;
 
     /* Duplicate path. */
     if (!(path_dup = strdup(path)))
     {
         LOG_MSG("Unable to duplicate input path! (\"%s\").", path);
-        return NULL;
+        goto end;
     }
 
     /* Remove any trailing slashes. */
@@ -403,42 +460,45 @@ end:
 bool romfsGeneratePathFromDirectoryEntry(RomFileSystemContext *ctx, RomFileSystemDirectoryEntry *dir_entry, char *out_path, size_t out_path_size, u8 illegal_char_replace_type)
 {
     size_t path_len = 0;
-    u32 dir_offset = ROMFS_VOID_ENTRY, dir_entries_count = 0;
+    u64 dir_offset = ROMFS_VOID_ENTRY;
+    u32 dir_entries_count = 0;
     RomFileSystemDirectoryEntry **dir_entries = NULL, **tmp_dir_entries = NULL;
     bool success = false;
 
-    if (!ctx || !ctx->dir_table || !ctx->dir_table_size || !dir_entry || (!dir_entry->name_length && dir_entry->parent_offset) || !out_path || out_path_size < 2 || \
+    if (!romfsIsValidContext(ctx) || !dir_entry || (!dir_entry->name_length && dir_entry->parent_offset) || !out_path || out_path_size < 2 || \
         illegal_char_replace_type > RomFileSystemPathIllegalCharReplaceType_KeepAsciiCharsOnly)
     {
         LOG_MSG("Invalid parameters!");
         return false;
     }
 
-    /* Check if we're dealing with the root directory entry. */
+    /* Short-circuit: check if we're dealing with the root directory entry. */
     if (!dir_entry->name_length)
     {
         sprintf(out_path, "/");
         return true;
     }
 
-    /* Allocate memory for our directory entries. */
+    /* Allocate memory for our directory entries pointer array. */
     dir_entries = calloc(1, sizeof(RomFileSystemDirectoryEntry*));
     if (!dir_entries)
     {
         LOG_MSG("Unable to allocate memory for directory entries!");
-        return false;
+        goto end;
     }
 
+    /* Update stats. */
     path_len = (1 + dir_entry->name_length);
     *dir_entries = dir_entry;
     dir_entries_count++;
 
     while(true)
     {
+        /* Get parent directory offset. Break out of the loop if we reached the root directory. */
         dir_offset = dir_entries[dir_entries_count - 1]->parent_offset;
         if (!dir_offset) break;
 
-        /* Reallocate directory entries. */
+        /* Reallocate directory entries pointer array. */
         if (!(tmp_dir_entries = realloc(dir_entries, (dir_entries_count + 1) * sizeof(RomFileSystemDirectoryEntry*))))
         {
             LOG_MSG("Unable to reallocate directory entries buffer!");
@@ -448,6 +508,7 @@ bool romfsGeneratePathFromDirectoryEntry(RomFileSystemContext *ctx, RomFileSyste
         dir_entries = tmp_dir_entries;
         tmp_dir_entries = NULL;
 
+        /* Retrieve parent directory entry using the offset we got earlier. */
         RomFileSystemDirectoryEntry **cur_dir_entry = &(dir_entries[dir_entries_count]);
         if (!(*cur_dir_entry = romfsGetDirectoryEntryByOffset(ctx, dir_offset)) || !(*cur_dir_entry)->name_length)
         {
@@ -455,37 +516,44 @@ bool romfsGeneratePathFromDirectoryEntry(RomFileSystemContext *ctx, RomFileSyste
             goto end;
         }
 
+        /* Update stats. */
         path_len += (1 + (*cur_dir_entry)->name_length);
         dir_entries_count++;
     }
 
+    /* Make sure the output buffer is big enough to hold the full path + NULL terminator. */
     if (path_len >= out_path_size)
     {
-        LOG_MSG("Output path length exceeds output buffer size!");
+        LOG_MSG("Output path length exceeds output buffer size! (%lu >= %lu).", path_len, out_path_size);
         goto end;
     }
 
-    /* Generate output path. */
+    /* Generate output path, looping through our directory entries pointer array in reverse order. */
     *out_path = '\0';
     path_len = 0;
 
     for(u32 i = dir_entries_count; i > 0; i--)
     {
-        RomFileSystemDirectoryEntry **cur_dir_entry = &(dir_entries[i - 1]);
+        /* Get current directory entry. */
+        RomFileSystemDirectoryEntry *cur_dir_entry = dir_entries[i - 1];
 
+        /* Concatenate path separator and current directory name to the output buffer. */
         strcat(out_path, "/");
-        strncat(out_path, (*cur_dir_entry)->name, (*cur_dir_entry)->name_length);
+        strncat(out_path, cur_dir_entry->name, cur_dir_entry->name_length);
         path_len++;
 
         if (illegal_char_replace_type)
         {
+            /* Replace illegal characters within this directory name, then update the full path length. */
             utilsReplaceIllegalCharacters(out_path + path_len, illegal_char_replace_type == RomFileSystemPathIllegalCharReplaceType_KeepAsciiCharsOnly);
             path_len += strlen(out_path + path_len);
         } else {
-            path_len += (*cur_dir_entry)->name_length;
+            /* Update full path length. */
+            path_len += cur_dir_entry->name_length;
         }
     }
 
+    /* Update return value. */
     success = true;
 
 end:
@@ -498,8 +566,9 @@ bool romfsGeneratePathFromFileEntry(RomFileSystemContext *ctx, RomFileSystemFile
 {
     size_t path_len = 0;
     RomFileSystemDirectoryEntry *dir_entry = NULL;
+    bool success = false;
 
-    if (!ctx || !ctx->file_table || !ctx->file_table_size || !file_entry || !file_entry->name_length || !out_path || out_path_size < 2 || \
+    if (!romfsIsValidContext(ctx) || !file_entry || !file_entry->name_length || !out_path || out_path_size < 2 || \
         !(dir_entry = romfsGetDirectoryEntryByOffset(ctx, file_entry->parent_offset)) || illegal_char_replace_type > RomFileSystemPathIllegalCharReplaceType_KeepAsciiCharsOnly)
     {
         LOG_MSG("Invalid parameters!");
@@ -510,35 +579,41 @@ bool romfsGeneratePathFromFileEntry(RomFileSystemContext *ctx, RomFileSystemFile
     if (!romfsGeneratePathFromDirectoryEntry(ctx, dir_entry, out_path, out_path_size, illegal_char_replace_type))
     {
         LOG_MSG("Failed to retrieve RomFS directory path!");
-        return false;
+        goto end;
     }
 
-    /* Check path length. */
+    /* Make sure the output buffer is big enough to hold the full path + NULL terminator. */
     path_len = strlen(out_path);
-    if ((1 + file_entry->name_length) >= (out_path_size - path_len))
+    if ((path_len + 1 + file_entry->name_length) >= out_path_size)
     {
-        LOG_MSG("Output path length exceeds output buffer size!");
+        LOG_MSG("Output path length exceeds output buffer size! (%lu >= %lu).", path_len + 1 + file_entry->name_length, out_path_size);
-        return false;
+        goto end;
     }
 
-    /* Concatenate file entry name. */
+    /* Concatenate path separator if our parent directory isn't the root directory. */
     if (file_entry->parent_offset)
     {
         strcat(out_path, "/");
         path_len++;
     }
 
+    /* Concatenate file entry name. */
     strncat(out_path, file_entry->name, file_entry->name_length);
 
+    /* Replace illegal characters within the file name, if needed. */
     if (illegal_char_replace_type) utilsReplaceIllegalCharacters(out_path + path_len, illegal_char_replace_type == RomFileSystemPathIllegalCharReplaceType_KeepAsciiCharsOnly);
 
-    return true;
+    /* Update return value. */
+    success = true;
+
+end:
+    return success;
 }
 
 bool romfsGenerateFileEntryPatch(RomFileSystemContext *ctx, RomFileSystemFileEntry *file_entry, const void *data, u64 data_size, u64 data_offset, RomFileSystemFileEntryPatch *out)
 {
-    if (!ctx || ctx->is_patch || !ncaStorageIsValidContext(ctx->default_storage_ctx) || ctx->default_storage_ctx->base_storage_type != NcaStorageBaseStorageType_Regular || \
+    if (!romfsIsValidContext(ctx) || ctx->is_patch || ctx->default_storage_ctx->base_storage_type != NcaStorageBaseStorageType_Regular || \
-        !ctx->body_offset || (ctx->default_storage_ctx->nca_fs_ctx->section_type != NcaFsSectionType_Nca0RomFs && ctx->default_storage_ctx->nca_fs_ctx->section_type != NcaFsSectionType_RomFs) || \
+        (ctx->default_storage_ctx->nca_fs_ctx->section_type != NcaFsSectionType_Nca0RomFs && ctx->default_storage_ctx->nca_fs_ctx->section_type != NcaFsSectionType_RomFs) || \
         !file_entry || !file_entry->size || (file_entry->offset + file_entry->size) > ctx->size || !data || !data_size || (data_offset + data_size) > file_entry->size || !out)
     {
         LOG_MSG("Invalid parameters!");
@@ -572,24 +647,28 @@ static RomFileSystemDirectoryEntry *romfsGetChildDirectoryEntryByName(RomFileSys
     size_t name_len = 0;
     RomFileSystemDirectoryEntry *child_dir_entry = NULL;
 
-    if (!ctx || !ctx->dir_table || !ctx->dir_table_size || !dir_entry || (dir_offset = dir_entry->directory_offset) == ROMFS_VOID_ENTRY || !name || !(name_len = strlen(name)))
+    if (!dir_entry || (dir_offset = dir_entry->directory_offset) == ROMFS_VOID_ENTRY || !name || !(name_len = strlen(name)))
     {
         LOG_MSG("Invalid parameters!");
         return NULL;
     }
 
+    /* Loop through the child directory entries' linked list. */
     while(dir_offset != ROMFS_VOID_ENTRY)
     {
+        /* Get current directory entry. */
         if (!(child_dir_entry = romfsGetDirectoryEntryByOffset(ctx, dir_offset)))
         {
-            LOG_MSG("Failed to retrieve directory entry at offset 0x%lX!", dir_offset);
+            LOG_MSG("Failed to retrieve directory entry! (0x%lX, 0x%lX).", dir_offset, ctx->dir_table_size);
             break;
         }
 
+        /* Check if we found the right child directory entry. */
         /* strncmp() is used here instead of strcmp() because names stored in RomFS sections are not always NULL terminated. */
         /* If the name ends at a 4-byte boundary, the next entry starts immediately. */
         if (child_dir_entry->name_length == name_len && !strncmp(child_dir_entry->name, name, name_len)) return child_dir_entry;
 
+        /* Update current directory entry offset. */
         dir_offset = child_dir_entry->next_offset;
     }
 
@@ -602,21 +681,23 @@ static RomFileSystemFileEntry *romfsGetChildFileEntryByName(RomFileSystemContext
     size_t name_len = 0;
     RomFileSystemFileEntry *child_file_entry = NULL;
 
-    if (!ctx || !ctx->dir_table || !ctx->dir_table_size || !ctx->file_table || !ctx->file_table_size || !dir_entry || (file_offset = dir_entry->file_offset) == ROMFS_VOID_ENTRY || \
+    if (!dir_entry || (file_offset = dir_entry->file_offset) == ROMFS_VOID_ENTRY || !name || !(name_len = strlen(name)))
-        !name || !(name_len = strlen(name)))
     {
         LOG_MSG("Invalid parameters!");
         return NULL;
     }
 
+    /* Loop through the child file entries' linked list. */
     while(file_offset != ROMFS_VOID_ENTRY)
     {
+        /* Get current file entry. */
         if (!(child_file_entry = romfsGetFileEntryByOffset(ctx, file_offset)))
         {
-            LOG_MSG("Failed to retrieve file entry at offset 0x%lX!", file_offset);
+            LOG_MSG("Failed to retrieve file entry! (0x%lX, 0x%lX).", file_offset, ctx->file_table_size);
             break;
         }
 
+        /* Check if we found the right child file entry. */
         /* strncmp() is used here instead of strcmp() because names stored in RomFS sections are not always NULL terminated. */
         /* If the name ends at a 4-byte boundary, the next entry starts immediately. */
         if (child_file_entry->name_length == name_len && !strncmp(child_file_entry->name, name, name_len)) return child_file_entry;