fix: new spinlock implementation, ramdisk max files, wallpaper scan locations

kernel/src/CppLib/Spinlock.cpp

@@ -8,12 +8,17 @@
 
 namespace kcp {
     void Spinlock::Acquire() {
+        uint64_t flags;
+        asm volatile("pushfq; pop %0; cli" : "=r"(flags) :: "memory");
         while (atomic_flag.test_and_set(std::memory_order_acquire)) {
             asm volatile("pause");
         }
+        savedFlags = flags;
     }
 
     void Spinlock::Release() {
+        uint64_t flags = savedFlags;
         atomic_flag.clear(std::memory_order_release);
+        asm volatile("push %0; popfq" :: "r"(flags) : "memory");
     }
 };

kernel/src/CppLib/Spinlock.hpp

@@ -10,6 +10,7 @@
 namespace kcp {
     class Spinlock {
         std::atomic_flag atomic_flag{ATOMIC_FLAG_INIT};
+        uint64_t savedFlags = 0;
     public:
         void Acquire();
         void Release();

kernel/src/Fs/Ramdisk.hpp

@@ -10,7 +10,7 @@
 
 namespace Fs::Ramdisk {
 
-    static constexpr int MaxFiles = 256;
+    static constexpr int MaxFiles = 512;
     static constexpr int MaxNameLen = 100;
 
     struct FileEntry {

programs/src/desktop/apps/app_settings.cpp

@@ -177,7 +177,7 @@ static void settings_draw_appearance(Canvas& c, SettingsState* st) {
     if (mode_image) {
         // Scan for images lazily
         if (!st->wp_scanned) {
-            wallpaper_scan_dir(st->desktop->home_dir, &st->wp_files);
+            wallpaper_scan_home(st->desktop->home_dir, &st->wp_files);
             st->wp_scanned = true;
         }
 
@@ -1156,7 +1156,7 @@ static void settings_on_mouse(Window* win, MouseEvent& ev) {
             s.bg_image = true;
             s.bg_gradient = false;
             if (!st->wp_scanned) {
-                wallpaper_scan_dir(st->desktop->home_dir, &st->wp_files);
+                wallpaper_scan_home(st->desktop->home_dir, &st->wp_files);
                 st->wp_scanned = true;
             }
             settings_persist(st);

programs/src/desktop/wallpaper.hpp

@@ -139,9 +139,11 @@ struct WallpaperFileList {
     int count;
 };
 
-inline void wallpaper_scan_dir(const char* dir_path, WallpaperFileList* list) {
+// Scan dir_path for JPEG files and append to list.
-    list->count = 0;
+// name_prefix is prepended to each stored filename (e.g. "Pictures/").
-
+// Caller must zero list->count before the first call if starting fresh.
+inline void wallpaper_scan_dir(const char* dir_path, WallpaperFileList* list,
+                               const char* name_prefix = nullptr) {
     const char* raw_names[64];
     int total = montauk::readdir(dir_path, raw_names, 64);
     if (total <= 0) return;
@@ -165,6 +167,8 @@ inline void wallpaper_scan_dir(const char* dir_path, WallpaperFileList* list) {
         }
     }
 
+    int np_len = name_prefix ? montauk::slen(name_prefix) : 0;
+
     auto to_lower = [](char c) -> char {
         return (c >= 'A' && c <= 'Z') ? (char)(c + 32) : c;
     };
@@ -206,10 +210,34 @@ inline void wallpaper_scan_dir(const char* dir_path, WallpaperFileList* list) {
         }
 
         if (is_jpeg) {
-            montauk::strncpy(list->names[list->count], name, 63);
+            if (np_len > 0) {
+                montauk::strncpy(list->names[list->count], name_prefix, 63);
+                int cur = np_len < 63 ? np_len : 63;
+                montauk::strncpy(list->names[list->count] + cur, name,
+                                 63 - cur);
+            } else {
+                montauk::strncpy(list->names[list->count], name, 63);
+            }
             list->count++;
         }
     }
 }
 
+// Scan Pictures/ subdirectory first, then home directory.
+inline void wallpaper_scan_home(const char* home_dir, WallpaperFileList* list) {
+    list->count = 0;
+
+    char pictures[256];
+    montauk::strcpy(pictures, home_dir);
+    int hlen = montauk::slen(pictures);
+    if (hlen > 0 && pictures[hlen - 1] != '/') {
+        pictures[hlen++] = '/';
+        pictures[hlen] = '\0';
+    }
+    montauk::strncpy(pictures + hlen, "Pictures", 256 - hlen);
+
+    wallpaper_scan_dir(pictures, list, "Pictures/");
+    wallpaper_scan_dir(home_dir, list);
+}
+
 } // namespace gui