How to select board config
We use opensource idbloader(See Boot_option) on some chips (rk3036, rk3288) and its dmc driver can't support ddr-type autodetct, so the wrong ddr dts settings will make the board failed to enter u-boot.
PMIC setting usually is just important in kernel, but for the board using rk818, USB input current should be configured during boot stage.
Please note some board have disable emmc in u-boot though the hardware actually have emmc. (firefly-rk3288）