OMAPL-138 UART0 don't work in linux

Dear All:

I have got a SEED-DEC138board.

it use UART2 as debug console,

and now,i use UART0 for communication in linux,but it don't work at all,

i saw the questions in the forums:

http://e2e.ti.com/support/embedded/f/354/p/59241/212795.aspx#212795

http://e2e.ti.com/support/dsp/omap_applications_processors/f/42/t/36701.aspx

Could someone point it out for me?

Thanks a lot.