I.MX6 lcd lvds hdmi bootargs

/*********************************************************************
 *              I.MX6 lcd lvds hdmi bootargs
 * 声明：
 *     本文主要是记录I.MX6DL使用到的几种显示屏中的bootargs的参数设置。
 *
 *                                  2016-1-18 深圳 南山平山村 曾剑锋
 ********************************************************************/


一、参考文章：
    LCD colors look wrong. Android 4.3 with18-bit Parallel RGB on IMX6S.
        https://community.freescale.com/thread/327695
    Kernel parameters
        https://boundarydevices.com/configuring-i-mx6-machines-different-screens-nitrogen6x-sabre-lite/

二、bootargs配置：
    1. 默认配置
    //console=ttymxc0,115200 init=/init video=mxcfb0:dev=ldb,bpp=32 video=mxcfb1:off video=mxcfb2:off fbmem=10M fb0base=0x27b00000 vmalloc=400M androidboot.console=ttymxc0 androidboot.hardware=freescale
    
    2. 使用lcd作为显示输出
    //"bootargs=console=ttymxc0,115200 init=/init mxcfb0:dev=lcd,CLAA-WVGA,if=RGB666 video=mxcfb1:off video=mxcfb2:off fbmem=30M fb0base=0x27b00000 vmalloc=400M androidboot.console=ttymxc0 androidboot.hardware=freescale\0" \
    
    3. 使用mipi作为显示输出
    //"bootargs=console=ttymxc0,115200 init=/init video=mxcfb0:dev=mipi_dsi,TRULY-WVGA,if=RGB24 video=mxcfb1:off video=mxcfb2:off fbmem=30M fb0base=0x27b00000 vmalloc=400M androidboot.console=ttymxc0 androidboot.hardware=freescale\0" \
    
    4. 使用lvds作为显示输出
    //"bootargs=console=ttymxc0,115200 init=/init video=mxcfb0:dev=ldb,bpp=32 video=mxcfb1:off video=mxcfb2:off fbmem=30M fb0base=0x27b00000 vmalloc=400M androidboot.console=ttymxc0 androidboot.hardware=freescale\0" \
    
    5. 使用lvds+hdmi显示输出
    //"bootargs=console=ttymxc0,115200 init=/init video=mxcfb0:dev=ldb,800x480M@60,if=RGB666,bpp=32 video=mxcfb1:dev=hdmi,1920x1080M@60,if=RGB24,bpp=32 video=mxcfb2:off ldb=dul1 fbmem=10M,30M vmalloc=400M androidboot.console=ttymxc0 androidboot.hardware=freescale\0"     //"bootargs=console=ttymxc0,115200 init=/init video=mxcfb0:dev=ldb,LDB-XGA,bpp=32 video=mxcfb1:dev=hdmi,640x480M@60,if=RGB24,bpp=32 video=mxcfb2:off ldb=dul1 fbmem=10M,30M vmalloc=400M androidboot.console=ttymxc0 androidboot.hardware=freescale\0" \
    
    6. use for lvds with hdmi 800*600
    //"bootargs=console=ttymxc0,115200 init=/init video=mxcfb0:dev=ldb,800x600M@60,if=RGB666,bpp=32 video=mxcfb1:dev=hdmi,800x600M@60,if=RGB24,bpp=32 video=mxcfb2:off ldb=dul1 fbmem=10M,10M vmalloc=400M androidboot.console=ttymxc0 androidboot.hardware=freescale\0" \
    
    7. use for lvds with hdmi 1920*1080
    //"bootargs=console=ttymxc0,115200 init=/init video=mxcfb0:dev=ldb,800x480M@60,if=RGB666,bpp=32 video=mxcfb1:dev=hdmi,1920x1080M@60,if=RGB24,bpp=32 video=mxcfb2:off ldb=dul1 fbmem=10M,30M vmalloc=400M androidboot.console=ttymxc0 androidboot.hardware=freescale\0" \
    
    8. use for two lvds display
    //"bootargs=console=ttymxc0,115200 init=/init video=mxcfb0:dev=ldb,bpp=32,LDB-XGA ldb=dul0 video=mxcfb1:dev=ldb,bpp=32,LDB-XGA video=mxcfb2:off fbmem=10M fb0base=0x27b00000 vmalloc=400M androidboot.console=ttymxc0 androidboot.hardware=freescale\0" \
    
    9. use for 24bit lvds display 
    //"bootargs=console=ttymxc0,115200 init=/init video=mxcfb0:dev=ldb,LDB-XGA,if=RGB24,fbpix=RGB32 video=mxcfb1:off video=mxcfb2:off fbmem=40M fb0base=0x27b00000 vmalloc=400M androidboot.console=ttymxc0 androidboot.hardware=freescale\0" \