en:u3_tips [ODROID Wiki]

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====== Tips for ODROID-U3 ======
This page introduce you an useful tips to use **ODROID-U3**.
----
====== How to change HDMI output resolution ======
**ODROID-U3** can support various resolution on HDMI output, you can select one of supported resolutions for your display (LCD monitor or TV).
<WRAP left round tip 100%>
Please make sure the resolution you select can be supported by your display before you start. Otherwise you would be hard to recover the resolution again.
</WRAP>
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Supported resolutions
  - 1920x1080 (1080p)
  - 1280x720 (720p)
</WRAP>



===== Android =====
We provide you a simple but useful application, **ODROID Utility**. This helps you to change the resolution by menu as below and you can select one of them for your display. Once you select one, click the button **Apply and Reboot**. Then your **ODROID-U3** will restart with new resolution.
{{:en:utility_resolution.png?640|}}
===== Linux / Ubuntu =====
Coming soon...
===== Lowlevel Change =====
This section introduce you to change the resolution by manual, this would be helpful if you are failure to change the resolution and not able to sett the face of **ODROID-C1**.

The fact what initiate the resolution is from **U-boot** and the environment key is **hdmimode**. Probably your U-boot would have the one like this by default.
<code>
odroidc#print hdmimode
hdmimode=720p
</code>
This will be passed to Linux kernel by **bootargs** just before Linux kernel is started. Here is the default value of **bootcmd** which starts Linux kernel. As you see, **hdmimode** is passing as boot argument.
<code>
odroidc#print bootcmd
bootcmd=cfgload;setenv bootargs root=/dev/mmcblk0p2 rw console=ttyS0,115200n8 no_console_suspend vd
accfg=${vdac_config} logo=osd1,loaded,${fb_addr},${outputmode},full hdmimode=${hdmimode} cvbsmode=$
{cvbsmode} hdmitx=${cecconfig} androidboot.serialno=${fbt_id#}; movi read boot 0 0x12000000;movi re
ad dtb 0 0x12800000;bootm 0x12000000 - 0x12800000
</code>
==== How to change the value of hdmimode ====
There are three ways to change **hdmimode** to change the resolution, you can replace **1080p** with the other resolution you wish to change for your display.
=== U-boot ===
If you are able to get into U-boot, this is simply possible with 3 commands below. This will change the resolution value and restart the board.
<code>
setenv hdmimode 1080p
saveenv
reset
</code>
=== Android shell ===
If you are able to use **adb shell**, then you can do these command to change **hdmimode**. This will change the resolution value and restart the board as well.
<code>
# fw_setenv hdmimode 1080p
# reboot
</code>
=== Boot.ini ===
You also can boot with **boot.ini** without changing U-boot environment values permanently. If **boot.ini** is existed in FAT partition **ODROID-C1** does boot with it first, unless boot with default setting stored in U-boot environment. You can download the file below and copy into your FAT partition.
<file ini boot.ini>
ODROIDC-UBOOT-CONFIG

setenv hdmimode 1080p
setenv bootargs "root=/dev/mmcblk0p2 rw console=ttyS0,115200n8 no_console_suspend vdaccfg=${vdac_config} logo=osd1,loaded,${fb_addr},${outputmode},full hdmimode=${hdmimode} cvbsmode=${cvbsmode} hdmitx=${cecconfig} androidboot.serialno=${fbt_id#}"
setenv bootcmd "movi read boot 0 0x12000000; movi read dtb 0 0x12800000; bootm 0x12000000 - 0x12800000"
run bootcmd
</file>
====== How to change U-boot configuration by BOOT.INI ======
----
In order to support easy boot loader setup, ODROID-C1 also support **boot.ini** as well as previous ODROID boards. So you can easily list up the commands what you want to executed in U-boot rather than the default. Here is the example to boot Ubuntu.
<file ini boot.ini>
ODROIDC-UBOOT-CONFIG

# Possible screen resolutions
# Uncomment only a single Line! The line with setenv written.
# At least one mode must be selected.

# setenv m "vga"          # VGA 640x480
# setenv m "480p"         # 480p 720x480
# setenv m "576p"         # 576p 720x576
# setenv m "800x480p60hz" # WVGA 800x480
# setenv m "720p"         # 720p 1280x720
# setenv m "800p"         # 800p(WXGA) 1280x800
# setenv m "sxga"         # SXGA 1280x1024
setenv m "1080p"        # 1080P 1920x1080
# setenv m "1920x1200"    # 1920x1200

# HDMI/DVI Mode Configuration
setenv vout_mode "hdmi"
# setenv vout_mode "dvi"

# HDMI BPP Mode
setenv m_bpp "32"
# setenv m_bpp "16"

# UHS Card Configuration
# Uncomment the line below to __DISABLE__ UHS-1 MicroSD support
# This might break boot for some brand/models of cards.
setenv disableuhs "disableuhs"

setenv bootargs "console=ttyS0,115200n8 root=UUID=e139ce78-9841-40fe-8823-96a304a09859 rootwait ro no_console_suspend vdaccfg=0xa000 logo=osd1,loaded,0x7900000,720p,full dmfc=3 cvbsmode=576cvbs hdmimode=${m} m_bpp=${m_bpp} vout=${vout_mode} ${disableuhs}"
setenv bootcmd "fatload mmc 0:1 0x21000000 uImage; fatload mmc 0:1 0x22000000 uInitrd; fatload mmc 0:1 0x21800000 meson8b_odroidc.dtb; bootm 0x21000000 0x22000000 0x21800000"
run bootcmd
</file>
===== Board Identifier =====
This is the keyword to identify the correct **BOOT.INI** as per board. For **ODROID-C1**, any **BOOT.INI** must contain **ODROIDC-UBOOT-CONFIG** and other commands must be below this.
===== U-boot commands =====
You can describe multiple commands of U-boot from the next line of **ODROIDC-UBOOT-CONFIG**. The commands are only restricted within the commands enabled by the running U-boot.