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.
ODROIDC-UBOOT-CONFIG
setenv hdmimode "720p"
# HDMI BPP Mode
setenv m_bpp "32"
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=${hdmimode} m_bpp=${m_bpp} mac=${ethaddr}"
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
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.
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.