[LinuxBIOS] uart_init hangs?

Corey Osgood corey_osgood at verizon.net
Mon Mar 26 08:10:20 CEST 2007

Alright, I know I ask too many questions, but what would cause uart_init
to hang? I'm trying to get serial output on ite it8705f, and my POST
card tells me that it's hanging during uart_init. I've made a bunch of
changes to it8705f_early_serial.c, mainly to set up serial port 1
manually, but nothing seems to help. Also, there's one small error in
the last line of that file, according to the datasheet:

    it8705f_sio_write(0x00, IT8705F_CONFIG_REG_CC, 0x02); //need to
change 0x02 to 0x01

Before I "fixed" that, LB got clear to the jump to RAM (according to the
POST card), but I had no serial output. Now I still have no serial
output and a hang at some point during uart_init. My mainboard code is
mostly a copy-and-paste of Via Epia-M, with the vga init code ripped out
for now. I'm using the "normal" 115200 baud and 8-N-1 settings, and I've
already checked that my serial setup is working, and according to linux,
the serial header  is actually COM1/ttyS0.

The other question is, does anything have to be done to the via vt8235
before serial setup?

Just for reference, if anyone wants them, datasheets:
ITE IT8705f: http://www.iteusa.com/product_info/file/pc/IT8705F_V.0.4.1.pdf
Via vt8235m: http://www.datasheetarchive.com/datasheet.php?article=3833808


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