[uClinux-dev] MCF5271EVB: console=ttyS2,115200 does not work

Greg Ungerer gerg at snapgear.com
Tue Feb 3 19:43:07 EST 2009

Hi Richard,

Richard Retanubun wrote:
> I am using a Motorola MCF5271EVB with U-boot 2009.01 and Linux 2.6.27 
> from kernel.org
> I customized the m5271evb_defconfig I got from the DENX linux-2.6 distro.
> I compiled in kernel bootargs with console=ttyS0,115200 and was able to 
> see the console output.
> Then I changed that line to console=ttyS2,115200, and am not able to get 
> the console output on any of the 3 UARTs.
> The deprecated mcfserial.c driver is limited to use ttyS0 or ttyS1. I am 
> able to crudely hack this to work with ttyS2.
> However, I am a bit lost with the newer mcf.c serial driver. What am I 
> missing that prevents me to use ttyS2 as my console?

Are the ttyS2 pins at the CPU multi-function (are they shared with
something else)?

It maybe that there is no appropriate setup to turn them into serial
lines in linux-2.6.x/arch/m68knommu/platform/527x/confnig.c. Look for
the m527x_uart_init_line() function.

This sort of setup used to be in the old mcfserial.c driver itself.
But the new style mcf.c is a true platform device, so the CPU/board
specific setup is now done in the platform code.


Greg Ungerer  --  Principal Engineer        EMAIL:     gerg at snapgear.com
SnapGear, a McAfee Company                  PHONE:       +61 7 3435 2888
825 Stanley St,                             FAX:         +61 7 3891 3630
Woolloongabba, QLD, 4102, Australia         WEB: http://www.SnapGear.com

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