There have been some problems with the UARTS. Here is an update on what we know.
UARTB (IMX31 UART 2) not working: Traced to an improper setting in the GPR register. Clear bit 0 of the GPR register. In lolo, use this command:
w /w 0x43FAC008 0x00000000
UART RTS/CTS not behaving as expected: We need to confirm with Freescale, but it appears the MX31 UARTs have a problem with the UFCR[DCEDTE] bit that allows RTS/CTS to be swapped on-chip. Because of this, the RTS/CTS signals are reversed from what you would expect. This does not affect RXD and TXD. For development, treat CTS as an output, and RTS as an input. If this is fixable, we will change RTS back to an output in the driver.