[U-Boot-Users] UART 16654

[Sam Song]

Wolfgang Denk <wd at denx.de> wrote：
> Jonas Dietsche <maillist at fsforth.de> wrote:
> > Using an u-boot with the NS16550 makes linux not
> > booting any more. The 
> > last message I get is "Starting kernel ...". It is

It seems that NS16550 driver in kernel wasn't enabled
or work right.

> The Linux drivers  must  not make any assumptions 
> about any initialization done or not done by any
> boot loader. Fix your Linux driver.

But one exception for serial console driver. I found
there wasn't enable control of UART receiver in 8xx
kerenl serial console driver uart.c. Maybe this driver
make a assumption that boot loader does this job? At
least I ported the driver work right on my 8xx custom
board without any change in it:-)

Also, sometimes we could initialize some status in
U-Boot for ready and then change it in kerenl to
finish some special work. I once made the LCD
backlight in boot process of my target like PC did to
aviod seeing the LCD screen flickering. First enable
and then shut down in u-boot, open it later in LCD
kernel driver:-)

IMHO, if one person did u-boot and kernel port both,
he would have the chance to consider the harmony
between U-Boot and Kernel. So some initialization like
receiver enable in kernel driver could be omitted. Is
this an informal idea?

Thanks for your nice time,

=====
Best regards,

Sam

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