I *think* this board is getting the wrong fdtfile set:
U-Boot 2019.01+dfsg-1 (Jan 15 2019 - 00:36:19 +0000)
CPU: Freescale i.MX6Q rev1.5 996 MHz (running at 792 MHz) CPU: Extended Commercial temperature grade (-20C to 105C) at 37C Reset cause: WDOG Board: MX6 Cubox-i DRAM: 3.8 GiB MMC: FSL_SDHC: 0, FSL_SDHC: 1 Loading Environment from MMC... *** Warning - bad CRC, using default environment
No panel detected: default to HDMI Display: HDMI (1024x768) In: serial Out: serial Err: serial Card did not respond to voltage select! Net: FEC Hit any key to stop autoboot: 0 => printenv som_rev som_rev=undefined => printenv has_emmc has_emmc=undefined => printenv findfdt findfdt=if test ${board_rev} = MX6Q; then setenv fdtprefix imx6q; fi; if test ${board_rev} = MX6DL; then setenv fdtprefix imx6dl; fi; if test ${som_rev} = V15; then setenv fdtsuffix -som-v15; fi; if test ${has_emmc} = yes; then setenv emmcsuffix -emmc; fi; if test ${board_name} = HUMMINGBOARD2 ; then setenv fdtfile ${fdtprefix}-hummingboard2${emmcsuffix}${fdtsuffix}.dtb; fi; if test ${board_name} = HUMMINGBOARD ; then setenv fdtfile ${fdtprefix}-hummingboard${emmcsuffix}${fdtsuffix}.dtb; fi; if test ${board_name} = CUBOXI ; t=> => run findfdt => printenv fdtfile fdtfile=imx6q-cubox-i.dtb
It pretty clearly identifies itself as a rev1.5 in the boot message, but som_rev is set to undefined, and so it sets fdtfile to the default version.
I haven't had a chance to check a newer version of u-boot, but I don't see any obvious changes for this board since v2019.01.
My *hunch* is it's either of these two commits, since it was detecting it correctly in v2018.07:
19ed6063a567c6924dbfc358bf4ce9a60a31c567 mx6cuboxi: Use mmc_get_op_cond() to check for an eMMC
86e5a7fc13d4eb7e21630b9d421469c663dc8c77 mx6cuboxi: Add support for eMMC booting
live well, vagrant