I've made a SD card image (.sdcard) using bitbake. I used Linux dd command to write it to SD card. I inserted the SD card to the SABRE board but it does not boot. It should not be SABRE board issue because it boots from another SD card which was bundled in the SABRE design package. My understanding is that the .sdcard contains U-boot even though I cannot read it by mounting /dev/mmcblk0p*.
Do you have any suggestion how I debug?