Index: dev/mainbus.c
===================================================================
RCS file: /cvs/src/sys/arch/arm64/dev/mainbus.c,v
diff -u -p -r1.32 mainbus.c
--- dev/mainbus.c	18 Nov 2024 05:32:39 -0000	1.32
+++ dev/mainbus.c	13 Jul 2025 07:21:55 -0000
@@ -38,7 +38,8 @@ int mainbus_match_primary(struct device 
 int mainbus_match_secondary(struct device *, void *, void *);
 void mainbus_attach_psci(struct device *);
 void mainbus_attach_efi(struct device *);
-void mainbus_attach_apm(struct device *);
+void mainbus_attach_subsystem(struct device *, const char *);
+void mainbus_attach_late(struct device *);
 void mainbus_attach_framebuffer(struct device *);
 void mainbus_attach_firmware(struct device *);
 void mainbus_attach_resvmem(struct device *);
@@ -147,7 +148,7 @@ mainbus_attach(struct device *parent, st
 		    sc->sc_rangeslen);
 	}
 
-	mainbus_attach_apm(self);
+	mainbus_attach_subsystem(self, "apm");
 
 	/* Scan the whole tree. */
 	for (sc->sc_early = 2; sc->sc_early >= 0; sc->sc_early--) {
@@ -156,13 +157,19 @@ mainbus_attach(struct device *parent, st
 	}
 	sc->sc_early = 0;
 
+	config_mountroot(self, mainbus_attach_late);
+
+	thermal_init();
+}
+
+void
+mainbus_attach_late(struct device *self)
+{
 	/*
 	 * Delay attaching the framebuffer to give other drivers a
 	 * chance to claim it.
 	 */
-	config_mountroot(self, mainbus_attach_framebuffer);
-
-	thermal_init();
+	mainbus_attach_framebuffer(self);
 }
 
 int
@@ -399,15 +406,27 @@ mainbus_attach_efi(struct device *self)
 	config_found(self, &fa, NULL);
 }
 
-void
-mainbus_attach_apm(struct device *self)
+static int
+mainbus_match_subsystem(struct device *parent, void *match, void *aux)
 {
-	struct fdt_attach_args fa;
+	struct cfdata *cf = match;
+	struct fdt_attach_args *fa = aux;
 
-	memset(&fa, 0, sizeof(fa));
-	fa.fa_name = "apm";
+	if (strcmp(cf->cf_driver->cd_name, fa->fa_name) == 0)
+		return cf->cf_attach->ca_match(parent, match, aux);
 
-	config_found(self, &fa, NULL);
+	return (0);
+}
+
+void
+mainbus_attach_subsystem(struct device *self, const char *name)
+{
+	struct fdt_attach_args fa = { .fa_name = name };
+	void *match;
+
+	match = config_search(mainbus_match_subsystem, self, &fa);
+	if (match != NULL)
+		config_attach(self, match, &fa, mainbus_print);
 }
 
 void