Implement read_dir_entry () VFS op, CE add ls command

kernel/syscall/syscall.c

@@ -371,7 +371,7 @@ DEFINE_SYSCALL (sys_read) {
     return SYSRESULT (-ST_BAD_ADDRESS_SPACE);
 
   spin_lock (&proc->lock);
-  int ret = vfs_read (proc, proc->cwv, path, buffer, off, size, rctx);
+  int ret = vfs_read (proc, proc->cwv, path, buffer, off, size);
   spin_unlock (&proc->lock);
 
   return SYSRESULT (ret);
@@ -401,7 +401,7 @@ DEFINE_SYSCALL (sys_describe) {
     return SYSRESULT (-ST_BAD_ADDRESS_SPACE);
 
   spin_lock (&proc->lock);
-  int ret = vfs_describe (proc, proc->cwv, path, desc, rctx);
+  int ret = vfs_describe (proc, proc->cwv, path, desc);
   spin_unlock (&proc->lock);
 
   return SYSRESULT (ret);
@@ -419,6 +419,37 @@ DEFINE_SYSCALL (sys_get_procgroup) {
   return SYSRESULT (target_proc->procgroup->pgid);
 }
 
+/* int read_dir_entry (char* path, struct dir_entry* entry, size_t entry_num) */
+DEFINE_SYSCALL (sys_read_dir_entry) {
+  uintptr_t uvaddr_path = a1;
+  uintptr_t uvaddr_entry = a2;
+  size_t entry_num = (size_t)a3;
+
+  struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
+
+  uintptr_t out_paddr;
+
+  spin_lock (&proc->procgroup->lock);
+  out_paddr = mm_v2p (&proc->procgroup->pd, uvaddr_path);
+  spin_unlock (&proc->procgroup->lock);
+
+  if (out_paddr == 0)
+    return SYSRESULT (-ST_BAD_ADDRESS_SPACE);
+
+  const char* path = (const char*)((uintptr_t)hhdm->offset + out_paddr);
+
+  struct dir_entry* entry = sys_get_user_buffer (proc, uvaddr_entry, sizeof (struct dir_entry));
+
+  if (entry == NULL)
+    return SYSRESULT (-ST_BAD_ADDRESS_SPACE);
+
+  spin_lock (&proc->lock);
+  int ret = vfs_read_dir_entry (proc, proc->cwv, path, entry, entry_num);
+  spin_unlock (&proc->lock);
+
+  return SYSRESULT (ret);
+}
+
 /* int get_exec_pid (void) */
 DEFINE_SYSCALL (sys_get_exec_pid) { return SYSRESULT (proc->exec_pid); }
 
@@ -444,6 +475,7 @@ static syscall_handler_func_t handler_table[] = {
     [SYS_MAIL_RECEIVE] = &sys_mail_receive,
     [SYS_GET_PROCGROUP] = &sys_get_procgroup,
     [SYS_GET_EXEC_PID] = &sys_get_exec_pid,
+    [SYS_READ_DIR_ENTRY] = &sys_read_dir_entry,
 };
 
 syscall_handler_func_t syscall_find_handler (int syscall_num) {