UEFI BIOS: eMMC initialization incomplete?

I am using the UEFI BIOS to boot NetBSD on my HoneyComb LX2. NetBSD attaches two SD/MMC buses at two individual SDHC controllers, sdmmc0 at sdhc0 and sdmmc1 at sdhc1. At sdmmc1 it attaches a logical disk for my micro SD card.

I have surmised that the onboard 64GB eMMC storage should attach at sdmmc0, however, NetBSD attaches no logical disk there. Is it possible that the UEFI BIOS has not activated and/or forced the assertion of some media-detect pin? I ask because I understand that in Linux there may be patches to support a quick of the HoneyComb’s configuration.

There is no media-detect pin for eMMC. It is non-removable storage. It is up to the host OS driver to detect and initialize the device.