My custom DM8148 board is not booting properly from an SD card. I'm using u-boot modified to use UART4 for console, and the board has 4 of MT41J64M16JT-15E (128Mx16) RAM chips. On release of reset, there's a 100ms burst of activity from the SD card, followed by the DDR clock starting (400MHz) and then a burst of activity on the DDR3, followed by nothing. I'm not seeing any output on the UART.
After running the DDR3 init scripts provided for DDR3 leveling, I can use CCS to access the RAM successfully (I can fill with 0s and Fs , and both read back properly), so the RAM appears to be working.
The one difference in SD card connections between my board and the EVM is that I don't have the SD write protect pin connected. Would that make u-boot halt? Does u-boot look at either the SDCD or SDWP pins?
Has anyone else had this problem? How would I go about debugging this?