关于全志V40 开机显示的选择HDMI、 VGA、 LCD、 AV
全志V40 接口非常丰富，显示支持以下接口（Supports Support RGB/LVDS/HDMI/MIPI DSI/TV Out），目前我们已经实现了双显输出，这些搭配通常的应用场景如广告机，收银机、自动售卖机等等，再通过系统api现实双屏异显，可以做很多延伸的项目，实用性还是非常强大的。因为V40属于4x核Quad-core ARM Cortex™-A7， Mali400 MP2 GPU，性能整体上比A20强。
1.HDMI + LVDS
2.HDMI + VGA
3.HDMI + AV OUT
以下是HDMI + AV OUT的配置，实现开机双屏显示。
;----------------------------------------------------------------------------------
;disp init configuration;
;disp_mode (0:screen0
;screenx_output_type (0:none; 1:lcd; 3:hdmi;)
;screenx_output_mode (used for hdmi output, 0:480i 1:576i 2:480p 3:576p 4:720p50)
; (5:720p60 6:1080i50 7:1080i60 8:1080p24 9:1080p50 10:1080p60)
;fbx format (4:RGB655 5:RGB565 6:RGB556 7:ARGB1555 8:RGBA5551 9:RGB888 10:ARGB8888 12:ARGB4444)
;fbx pixel sequence (0:ARGB 1:BGRA 2:ABGR 3:RGBA)
;fb0_scaler_mode_enable(scaler mode enable, used FE)
;fbx_width,fbx_height (framebuffer horizontal/vertical pixels, fix to output resolution while equal 0)
;lcdx_backlight (lcd init backlight,the range:[0,256],default:197
;lcdx_yy (lcd init screen bright/contrast/saturation/hue, value:0~100, default:50/50/57/50)
;lcd0_contrast (LCD contrast, 0~100)
;lcd0_saturation (LCD saturation, 0~100)
;lcd0_hue (LCD hue, 0~100)
;----------------------------------------------------------------------------------
[disp]
disp_init_enable = 1
disp_mode = 0
;uboot开机显示设置
;dev%d_output_type 1.LCD 2.TV 4.HDMI 8.VGA
dev0_output_type = 2
dev0_output_mode = 11
dev0_screen_id = 0
dev0_do_hpd = 1
def_output_dev = 0
hdmi_mode_check = 1
screen0_output_type = 2
screen0_output_mode = 11
screen1_output_type = 3
screen1_output_mode = 4
fb0_format = 0
fb0_width = 0
fb0_height = 0
fb1_format = 0
fb1_width = 0
fb1_height = 0
lcd0_backlight = 50
lcd1_backlight = 50
lcd0_bright = 50
lcd0_contrast = 50
lcd0_saturation = 57
lcd0_hue = 50
lcd1_bright = 50
lcd1_contrast = 50
lcd1_saturation = 57
lcd1_hue = 50
;----------------------------------------------------------------------------------
;lcd0 configuration
;lcd_if: 0:hv(sync+de); 1:8080; 2:ttl; 3:lvds; 4:dsi; 5:edp; 6:extend dsi
;lcd_x: lcd horizontal resolution
;lcd_y: lcd vertical resolution
;lcd_width: width of lcd in mm
;lcd_height: height of lcd in mm
;lcd_dclk_freq: in MHZ unit
;lcd_pwm_freq: in HZ unit
;lcd_pwm_pol: lcd backlight PWM polarity
;lcd_pwm_max_limit lcd backlight PWM max limit(<=255)
;lcd_hbp: hsync back porch
;lcd_ht: hsync total cycle
;lcd_vbp: vsync back porch
;lcd_vt: vysnc total cycle
;lcd_hspw: hsync plus width
;lcd_vspw: vysnc plus width
;lcd_lvds_if: 0:single link; 1:dual link
;lcd_lvds_colordepth: 0:8bit; 1:6bit
;lcd_lvds_mode: 0:NS mode; 1:JEIDA mode
;lcd_frm: 0:disable; 1:enable rgb666 dither; 2:enable rgb656 dither
;lcd_io_phase: 0:noraml; 1:intert phase(0~3bit: vsync phase; 4~7bit:hsync phase;
; 8~11bit:dclk phase; 12~15bit:de phase)
;lcd_gamma_en lcd gamma correction enable
;lcd_bright_curve_en lcd bright curve correction enable
;lcd_cmap_en lcd color map function enable
;deu_mode 0:smoll lcd screen; 1:large lcd screen(larger than 10inch)
;lcdgamma4iep: Smart Backlight parameter, lcd gamma vale * 10;
; decrease it while lcd is not bright enough; increase while lcd is too bright
;smart_color 90:normal lcd screen 65:retina lcd screen(9.7inch)
;----------------------------------------------------------------------------------
[lcd0]
lcd_used = 0
lcd_driver_name = "default_lcd"
lcd_backlight = 100
lcd_if = 3
lcd_x = 1920
lcd_y = 1080
lcd_width = 150
lcd_height = 94
lcd_dclk_freq = 150
lcd_pwm_used = 1
lcd_pwm_ch = 0
lcd_pwm_freq = 50000
lcd_pwm_pol = 1
lcd_pwm_max_limit = 255
lcd_hbp = 20
lcd_ht = 2200
lcd_hspw = 10
lcd_vbp = 10
lcd_vt = 2250
lcd_vspw = 5
lcd_lvds_if = 1
lcd_lvds_colordepth = 0
lcd_lvds_mode = 0
lcd_frm = 1
lcd_hv_clk_phase = 0
lcd_hv_sync_polarity= 0
lcd_gamma_en = 0
lcd_bright_curve_en = 0
lcd_cmap_en = 0
deu_mode = 1
lcdgamma4iep = 22
smart_color = 90
lcd_bl_en = 1
lcd_bl_en_used =1
lcd_bl_en =port:PB09<1><0>
lcd_power = "vcc-lcd"
lcdd0 = port:PD00<3><0>
lcdd1 = port:PD01<3><0>
lcdd2 = port:PD02<3><0>
lcdd3 = port:PD03<3><0>
lcdd4 = port:PD04<3><0>
lcdd5 = port:PD05<3><0>
lcdd6 = port:PD06<3><0>
lcdd7 = port:PD07<3><0>
lcdd8 = port:PD08<3><0>
lcdd9 = port:PD09<3><0>
lcdd10 = port:PD10<3><0>
lcdd11 = port:PD11<3><0>
lcdd12 = port:PD12<3><0>
lcdd13 = port:PD13<3><0>
lcdd14 = port:PD14<3><0>
lcdd15 = port:PD15<3><0>
lcdd16 = port:PD16<3><0>
lcdd17 = port:PD17<3><0>
lcdd18 = port:PD18<3><0>
lcdd19 = port:PD19<3><0>
lcd_pin_power = "vcc-pd"
[lcd0_suspend]
lcdd0 = port:PD00<7><0>
lcdd1 = port:PD01<7><0>
lcdd2 = port:PD02<7><0>
lcdd3 = port:PD03<7><0>
lcdd4 = port:PD04<7><0>
lcdd5 = port:PD05<7><0>
lcdd6 = port:PD06<7><0>
lcdd7 = port:PD07<7><0>
lcdd8 = port:PD08<7><0>
lcdd9 = port:PD09<7><0>
lcdd10 = port:PD10<7><0>
lcdd11 = port:PD11<7><0>
lcdd12 = port:PD12<7><0>
lcdd13 = port:PD13<7><0>
lcdd14 = port:PD14<7><0>
lcdd15 = port:PD15<7><0>
lcdd16 = port:PD16<7><0>
lcdd17 = port:PD17<7><0>
lcdd18 = port:PD18<7><0>
lcdd19 = port:PD19<7><0>
;----------------------------------------------------------------------------------
;pwm config
;----------------------------------------------------------------------------------
[pwm0]
pwm_used = 1
pwm_positive = port:PB2<3><0>
[pwm0_suspend]
pwm_positive = port:PB2<7><0>
;----------------------------------------------------------------------------------
;hdmi configuration
;hdmi_used: if hdmi is used
;hdmi_hdcp_enable: if hdmi hdcp function enable
;hdmi_cts_compatibility:if hdmi cts test compatibility enable
;hdmi_power: power name for hdmi
;----------------------------------------------------------------------------------
[hdmi]
hdmi_used = 1
hdmi_hdcp_enable = 0
hdmi_cts_compatibility = 0
;----------------------------------------------------------------------------------
;tv configuration
;dac_src (dac no,support dac_src0~dac_src3,dac num max is 4)
;interface (interface type,1<->cvbs,2<->YPBPR,4<->SVIDEO)
;NOTE: tv0,tv1 can not use the same dac_src.
;----------------------------------------------------------------------------------
[tv0]
used = 1
dac_src0 = 3
dac_type0 = 0
interface = 1
以下是VGA 1080P的显示效果，实际屏幕我们没有去设置为1080P显示，只是驱动实际输出1080P数据
