branched to spi
adds door stub
spi merger v1
spi merger v2
spi merger v3
spi merger v4
spi merger v5
spi merger v6
spi merger v7
spi merger v8
spi merger v9
spi merger v10
spi merger v11
spi merger v12
spi merger v13
spi merger v14
spi merger v15
spi merger v16
spi merger v17
spi merger v18