NanoBSD 6.2 Stable fails to mount filesystem on MikroTik RouterBOARD 230

[M. Warner Losh]

In message: <45D8E3B0.6080909 at hockingits.com>
            Phill Hocking <phocking at hockingits.com> writes:
: Greetings. I am having issues with my NanoBSD images failing to boot 
: that seemed to start in 6.1.
: 
: RTC BIOS diagnostic error 20<config_unit>
: 
: Timecounters tick every 1.000 msec
: 
: ad0: 488MB <SanDisk SDCFB-512 HDX 3.15> at ata0-masstray irq7
: 
: ad0: TIMEOUT - READ_DMA retrying (1 retry left) LBA=0
: ad0: TIMEOUT - READ_DMA retrying (0 retries left) LBA=0
: ad0: FAILURE - READ_DMA timed out LBA=0
: ad0: TIMEOUT - READ_DMA retrying (1 retry left) LBA=0
: ad0: TIMEOUT - READ_DMA retrying (0 retries left) LBA=0
: ad0: FAILURE - READ_DMA timed out LBA=0
: ad0: TIMEOUT - READ_DMA retrying (1 retry left) LBA=1
: ad0: TIMEOUT - READ_DMA retrying (0 retries left) LBA=1
: ad0: FAILURE - READ_DMA timed out LBA=1
: ad0: TIMEOUT - READ_DMA retrying (1 retry left) LBA=0
: ad0: TIMEOUT - READ_DMA retrying (0 retries left) LBA=0
: ad0: FAILURE - READ_DMA timed out LBA=0
: Trying to mount root from ufs:/dev/ad0s1a
: 
: I've tried several different flash carts, and my old 5x images work, so 
: what should I do?

Add:
hw.ata.ata_dma=0
to /boot/loader.conf

This may be a case where a new DMA CF part is in an old non-DMA
adapter...  But I'd expect to see that with 4.x and 5.x too, but it
can't hurt to try.

Warner