I have successfully managed to boot an i.MX28 CPU (TQMa28 module) with u-boot 13.04. I have also ported an AUART driver that works with U-Boot 2009.08 to have the U-Boot output be sent to AUART3 instead of DUART. The issue though is that if I do not print anything at all to the DUART the AUART will fail to print anything. If I, during the initialization of the AUART driver, call pl01x_serial_putc(" "), then the AUART driver will work fine and all output will go to the correct AUART. If I omit that call to the pl01x_serial_putc the AUART will output nothing.
Are there any known problems with AUART during U-Boot or anything such? Or am I missing something cruical?