init+initrd: Create /tmp and mount it on boot

apps/init.cpp

@@ -149,10 +149,28 @@ static Result<void> load_service(const os::Path& path)
 
         if (parts[0].view() == "Command")
         {
+            if (!service.command.is_empty())
+            {
+                fprintf(g_init_log, "[init] 'Command' cannot be specified after 'Script' has already been set! (%s)\n",
+                        line.chars());
+                return {};
+            }
             service.command = move(parts[1]);
             continue;
         }
 
+        if (parts[0].view() == "Script")
+        {
+            if (!service.command.is_empty())
+            {
+                fprintf(g_init_log, "[init] 'Script' cannot be specified after 'Command' has already been set! (%s)\n",
+                        line.chars());
+                return {};
+            }
+            service.command = TRY(String::format("/bin/sh -- %s"_sv, parts[1].chars()));
+            continue;
+        }
+
         if (parts[0].view() == "Restart")
         {
             if (parts[1].view() == "true" || parts[1].view().to_uint().value_or(0) == 1)
@@ -210,7 +228,7 @@ static Result<void> load_service(const os::Path& path)
 
     if (service.command.is_empty())
     {
-        fprintf(g_init_log, "[init] service file is missing 'Command' entry, aborting!\n");
+        fprintf(g_init_log, "[init] service file is missing 'Command' or 'Script' entry, aborting!\n");
         return {};
     }
 

initrd/etc/init/00-tmpfs

@@ -0,0 +1,3 @@
+Name=tmpfs
+Script=/sbin/mount-tmpfs
+Wait=true

initrd/sbin/mount-tmpfs

@@ -0,0 +1,3 @@
+mkdir -p /tmp
+mount -t tmpfs /tmp
+chmod 1777 /tmp