Remove the unused 'b' slot
Although we can't opt-out A/B (because bootloader is built with
CONFIG_ANDROID_AB), but we can delete the unused 'b' slot as the update
of microdroid is not done by writing into the disk, but updating the
virt APEX that has the microdroid image.
Bug: N/A
Test: atest MicrodroidHostTestCases
Change-Id: Ie5871bf1b665e2cc564af54338043ae482ca01bb
diff --git a/microdroid/uboot-env.txt b/microdroid/uboot-env.txt
index 47b8f2c..585702e 100644
--- a/microdroid/uboot-env.txt
+++ b/microdroid/uboot-env.txt
@@ -1,7 +1,9 @@
# Static u-boot environment variables for microdroid. See b/180481192
# Boot the device following the Android boot procedure
-bootcmd=avb init virtio 0 && avb verify _a && boot_android virtio 0
+# `0` is the disk number of os_composite.img
+# `a` and `_a` are the slot index for A/B
+bootcmd=avb init virtio 0 && avb verify _a && boot_android virtio 0 a
bootdelay=0
fdtaddr=0x80000000