I have problems with settings for the CPM1 UART Serial driver
on MPC 880 custom board (with the custom bootloader) on Linux 2.6.10-rc3.
I could see that only 3 characters (see below) from the linux_banner are printed in __init start_kernel() (init/main.c) upon booting.
Then a lot of garbage is outputted and eventually kernel hangs ...
...
after gunzip
done.
Now booting the kernel
LinÿÿÿÿÿÿÿÿÀÿÿÿÿÿÿÿÿÀ8ÀÿÿÿÿÿÿÿÿÀXÀÿÿÿÿÿÿÿÿÀxÀÿÿÿÿÿÿÿÿÀ?ÀÿÿÿÿÿÿÿÿÀ¸ÀÿÿÿÿÿÿÿÿÀØÀÿÿ
<more garbage>
<hangs> ...
Slow debugging (via logbuf examination - no JTAG/BSD) shows that the kernel booting hangs (in the driver's ISR, which is cpm_uart_console_write - I suppose ) during the console_init() call
at about (or just soon after) console_drivers = console; statement in
register_console(struct console * console) function (in kernel/printk.c ).
I can not find (so far ) any specific error in values supplied via bd_info from the ("custom" modified pSOS bootloader) causing above problem. I have debug output showing my serial settings was saved into log buffer - if someone would dare to examine it - to see what is wrong there - I would be more than grateful to send it off-the-list !!!
Meanwhile - suppose I would disable (comment out in the main.c ) the console_init() call (is it "allowed" ???? ) and suppose (I do not know yet since I did not tried that) that the kernel booting
will continue without any additional problems and will successfully finish (just without the console ;-) )- is there any existant "non-standard" "debugging" "experimental" code, which I could integrate and execute with the aim to "late" launch my serial console at that point ?
Or may be someone is aware of some sort of "CPM diagnostic" software, that could be run upon kernel booting - (something developed by Motorola/FreeScale and posted as free software ?...)
Alternatively (or additionally) - why not (optionally) to
allow for the 8xx ppc kernel to use the simple serial console mechanism
(putc( ), puts( ), puthex( )), which is used (and, by the way, works in my case - as one could see from the quotted above booting output) in the "simple" bootloader (the 'middle-man' between the primary
bootloader and the kernel ) - may be by making it available to the kernel as a library ? Is such code available somewhere ?
Regards,
Alex
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