如何在linux kernel 4.4開啟支援VGA

Chip Platform Rockchip
1

想請問我想在firefly上用VGA顯示console,於是先修改了DTS

#include “rk3288-firefly.dtsi”

/ {
model = “Firefly-RK3288”;
compatible = “firefly,firefly-rk3288”, “rockchip,rk3288”;

    clk16m: clk16m {
            compatible = "fixed-clock";
            #clock-cells = <0>;
            clock-frequency = <16000000>;
    };

    panel: panel {
            compatible = "rockchip,vga";
            status = "okay";
            enable-gpios = <&gpio7 21 GPIO_ACTIVE_HIGH>
    };

};

然後在extlinux/extlinux.conf修改如下

label kernel-4.4
kernel /uImage
fdt /rk3288-firefly.dtb.img
append earlyprintk console=vga rw root=/dev/ram0 ramdisk_size=16384 initrd=/rd-ext2.bin.lzo.img quiet maxcpus=3 isolcpus=1,2 clk_ignore_unused

但vga都無ouput…想請問是有什麼地方沒有加到?

感謝