generator: Fixes for Android Boot environment

In Android Boot environment we do not parse ostree= karg to determine
what directory to boot into, alternatively we do this based on the
androidboot.slot_suffix= karg. But we do set ostree=true karg to denote
that we are indeed booting an ostree environment (required for some
systemd unit files). This chnage accounts for this approach in the
systemd generator. It first checks for presence of
androidboot.slot_suffix=, if that is not present it parse ostree= karg.
Here is what a cmdline may look like in this type of environment:

androidboot.slot_suffix=_a androidboot.bootdevice=*.ufshc root=PARTLABEL=system_a root=UUID=76a22bf4-f153-4541-b6c7-0332c0dfaeac rw ostree=true loglevel=4 acpi=off console=ttyAMA0 systemd.show_status=auto libahci.ignore_sss=1 slub_debug=FPZ fsck.mode=skip rcupdate.rcu_normal_after_boot=0 rcupdate.rcu_expedited=1

Signed-off-by: Eric Curtin <[email protected]>

src/libostree/ostree-impl-system-generator.c

@@ -261,17 +261,17 @@ _ostree_impl_system_generator (const char *normal_dir, const char *early_dir, co
   if (!cmdline)
     return glnx_throw (error, "Failed to read /proc/cmdline");
 
-  g_autofree char *ostree_cmdline = otcore_find_proc_cmdline_key (cmdline, "ostree");
-
+  g_autoptr (GError) otcore_get_ostree_target_error = NULL;
+  g_autofree char *ostree_target = NULL;
   /* This could happen in CoreOS live environments, where we hackily mock
    * the `ostree=` karg for `ostree-prepare-root.service` specifically, but
    * otherwise that karg doesn't exist on the real command-line. */
-  if (!ostree_cmdline)
+  if (!otcore_get_ostree_target (cmdline, &ostree_target, &otcore_get_ostree_target_error))
     return TRUE;
 
   if (!require_internal_units (normal_dir, early_dir, late_dir, error))
     return FALSE;
-  if (!fstab_generator (ostree_cmdline, normal_dir, early_dir, late_dir, error))
+  if (!fstab_generator (ostree_target, normal_dir, early_dir, late_dir, error))
     return FALSE;
 
   return TRUE;