From 6063608b2b212ab46aa287d0063007cae5ff429c Mon Sep 17 00:00:00 2001
From: Michael Stapelberg <michael@stapelberg.de>
Date: Thu, 17 May 2018 09:08:25 +0200
Subject: [PATCH] update: introduce a /bootonly handler for bakery

Regular updates hit /boot, /root, then /switch.

bakery only updates /boot, so we need to take care of persisting the active root
partition across /boot updates.
---
 update.go | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/update.go b/update.go
index 1438f0f..66c9253 100644
--- a/update.go
+++ b/update.go
@@ -130,6 +130,17 @@ func initUpdate() error {
 	http.HandleFunc("/update/boot", nonConcurrentUpdateHandler("/dev/mmcblk0p1"))
 	http.HandleFunc("/update/root", nonConcurrentUpdateHandler("/dev/mmcblk0p"+inactiveRootPartition))
 	http.HandleFunc("/update/switch", nonConcurrentSwitchHandler(inactiveRootPartition))
+	// bakery updates only the boot partition, which would reset the active root
+	// partition to 2.
+	updateHandler := nonConcurrentUpdateHandler("/dev/mmcblk0p1")
+	http.HandleFunc("/update/bootonly", func(w http.ResponseWriter, r *http.Request) {
+		updateHandler(w, r)
+		if err := switchRootPartition(rootPartition); err != nil {
+			log.Printf("switching root partition to %q failed: %v", rootPartition, err)
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+	})
 	http.HandleFunc("/reboot", func(w http.ResponseWriter, r *http.Request) {
 		if r.Method != http.MethodPost {
 			http.Error(w, "expected a POST request", http.StatusBadRequest)