feat: filesystem and Files app support for >64 file entries, 64-bit sizes, async ops, GUI toolkit improvements to devexplorer app

kernel/src/Fs/Fat32.cpp

@@ -674,11 +674,12 @@ namespace Fs::Fat32 {
 
     static int ReadDirectoryNames(int inst, uint32_t dirCluster,
                                    char outNames[MaxDirEntries][MaxNameLen],
-                                   int maxEntries) {
+                                   int maxEntries, int startOffset = 0) {
         auto& self = g_instances[inst];
         uint16_t lfnBuf[MaxNameLen];
         bool hasLfn = false;
         int count = 0;
+        int skipped = 0;   // valid entries skipped to reach startOffset
 
         uint32_t cluster = dirCluster;
         while (!IsEndOfChain(cluster) && count < maxEntries) {
@@ -736,6 +737,10 @@ namespace Fs::Fat32 {
                     outNames[count][len] = '\0';
                 }
 
+                // Skip entries before the requested page. The name above was
+                // written into outNames[count] as scratch and will be reused.
+                if (skipped < startOffset) { skipped++; continue; }
+
                 count++;
             }
 
@@ -997,7 +1002,7 @@ namespace Fs::Fat32 {
     }
 
     static int ReadDirImpl(int inst, const char* path,
-                            const char** outNames, int maxEntries) {
+                            const char** outNames, int maxEntries, int startIndex = 0) {
         if (inst < 0 || inst >= g_instanceCount) return -1;
         auto& self = g_instances[inst];
 
@@ -1006,7 +1011,7 @@ namespace Fs::Fat32 {
         if (!(dirEntry.attributes & ATTR_DIRECTORY)) return -1;
 
         int limit = maxEntries < MaxDirEntries ? maxEntries : MaxDirEntries;
-        int count = ReadDirectoryNames(inst, dirEntry.firstCluster, self.dirNames, limit);
+        int count = ReadDirectoryNames(inst, dirEntry.firstCluster, self.dirNames, limit, startIndex);
 
         self.dirNameCount = count;
         for (int i = 0; i < count; i++) {
@@ -1762,6 +1767,7 @@ namespace Fs::Fat32 {
         static uint64_t GetSize(int h) { return GetSizeImpl(N, h); }
         static void Close(int h) { CloseImpl(N, h); }
         static int ReadDir(const char* p, const char** o, int m) { return ReadDirImpl(N, p, o, m); }
+        static int ReadDirAt(const char* p, const char** o, int m, int s) { return ReadDirImpl(N, p, o, m, s); }
         static int Write(int h, const uint8_t* b, uint64_t o, uint64_t s) { return WriteImpl(N, h, b, o, s); }
         static int Create(const char* p) { return CreateImpl(N, p); }
         static int Delete(const char* p) { return DeleteImpl(N, p); }
@@ -1784,6 +1790,7 @@ namespace Fs::Fat32 {
             Thunks<N>::Mkdir,
             Thunks<N>::Rename,
             Thunks<N>::GetLabel,
+            Thunks<N>::ReadDirAt,
         };
     }