Thanks for the reply. I do have CONFIG_SERIAL_8250_CONSOLE enabled.
The console does work once the kernel boots and the driver init routines
However, if the kernel crashes before the driver init routines are run,
then I wasn't
getting any output. The old au1x00_uart.c driver was able to support an
console_init() in start_kernel(), on the Alchemy uart. However, after
looking at the new
8250 driver more closely, I see that it can not support the Alchemy uart
until after the
driver init routines are run.
I finally wrote a simple early console driver that relied on the boot
monitor setting up
the uart. This enabled me to figure out why the kernel was crashing
Jon Anders Haugum wrote:
On Wed, 22 Mar 2006, Mark Schank wrote:
I am working with a Au1550 based system an am trying to upgrade
from the 2.6.12 kernel to the 2.6.16 kernel . I have noticed that the
au1x00_uart.c driver has been remove and replaced with functionality in
8250.c and 8250_au1x00.c. So far, I have been unable to get the early
console running. Under this new driver model, what is the proper
way to bring up an early console on a Au1550 internal serial port?
Have you enabled the console for 8250-based serial ports?
Another issue might be if you have got some PCI-based serial ports in
the system, because they will be assigned before the internal ones. So
you might end up having the console on a PCI serial port.
Third: There is a bug in the new driver regarding divisor settings,
but the console should still be working since the boot loader will
init the uart properly. (I've posted a patch for this bug earlier: