Just copy one command line to Linux terminal… (copy-paste mode)
curl dl.khadas.com/online/rockchip-burn | sh -s - oowow --write --spi
curl dl.khadas.com/online/rockchip-burn | sh -s - android --write
curl dl.khadas.com/online/rockchip-burn | sh -s - oowow --write
curl dl.khadas.com/online/rockchip-burn | sh -s - ubuntu --write
rockchip-burn http://dl.khadas.com/products/oowow/system/versions/edge2/edge2-oowow-230308.000-sd.img.gz
rockchip-burn edge2-oowow-230308.000-spi.img.gz --spi
rockchip-burn ./edge2-oowow-230308.000-sd.img.gz
rockchip-burn ./edge2-oowow-230308.000-spi.img.gz --spi