FEAT: VFS overhaul

src/sys/kernel_subsystem.c

@@ -0,0 +1,73 @@
+#include "kernel_subsystem.h"
+#include "memory_manager.h"
+#include "spinlock.h"
+
+static kernel_subsystem_t subsystems[MAX_SUBSYSTEMS];
+static int subsystem_count = 0;
+static spinlock_t sub_lock = SPINLOCK_INIT;
+
+extern void mem_memset(void *dest, int val, size_t len);
+extern void mem_memcpy(void *dest, const void *src, size_t len);
+
+static void sub_strcpy(char *dest, const char *src) {
+    while (*src) *dest++ = *src++;
+    *dest = 0;
+}
+
+static int sub_strcmp(const char *a, const char *b) {
+    while (*a && *a == *b) { a++; b++; }
+    return (unsigned char)*a - (unsigned char)*b;
+}
+
+void subsystem_register(const char *name, kernel_subsystem_t **out_sub) {
+    uint64_t flags = spinlock_acquire_irqsave(&sub_lock);
+    
+    if (subsystem_count >= MAX_SUBSYSTEMS) {
+        spinlock_release_irqrestore(&sub_lock, flags);
+        if (out_sub) *out_sub = NULL;
+        return;
+    }
+
+    // Check if already exists
+    for (int i = 0; i < subsystem_count; i++) {
+        if (sub_strcmp(subsystems[i].name, name) == 0) {
+            spinlock_release_irqrestore(&sub_lock, flags);
+            if (out_sub) *out_sub = &subsystems[i];
+            return;
+        }
+    }
+
+    kernel_subsystem_t *s = &subsystems[subsystem_count++];
+    mem_memset(s, 0, sizeof(kernel_subsystem_t));
+    sub_strcpy(s->name, name);
+    
+    spinlock_release_irqrestore(&sub_lock, flags);
+    if (out_sub) *out_sub = s;
+}
+
+void subsystem_add_file(kernel_subsystem_t *sub, const char *name, 
+                        int (*read)(char*, int, int), 
+                        int (*write)(const char*, int, int)) {
+    if (!sub || sub->file_count >= MAX_SUBSYSTEM_FILES) return;
+    
+    subsystem_file_t *f = &sub->files[sub->file_count++];
+    sub_strcpy(f->name, name);
+    f->read = read;
+    f->write = write;
+}
+
+kernel_subsystem_t* subsystem_get_by_name(const char *name) {
+    for (int i = 0; i < subsystem_count; i++) {
+        if (sub_strcmp(subsystems[i].name, name) == 0) return &subsystems[i];
+    }
+    return NULL;
+}
+
+int subsystem_get_count(void) {
+    return subsystem_count;
+}
+
+kernel_subsystem_t* subsystem_get_by_index(int index) {
+    if (index < 0 || index >= subsystem_count) return NULL;
+    return &subsystems[index];
+}