I have no control over the bootloader but I would like to hardcode the kernel to output printk messages to serial console. Any advise where to insert such hardcoded behaviour ?

That's already the default for most platforms - what are you trying to do?

Thank you for your response.

I am currently working on a RTL8186 platform, using the sources on www.sourceforge.net/projects/rtl8186. Below is the output of the serial console, I don't see anything after "On node 0 totalpages: 16384", I suspect serial console is not the default behaviour.

UART1 output test ok
Uart init
mfid=000000c2 devid=00002249
Found 1 x 2M flash memory

---RealTek(RTL8186)at 2005.09.14-18:49+0800 version 1.3b [32bit](180MHz)

---Escape booting by user
<AboCom>
**TFTP Client Upload, File Name: root.bin
-
**TFTP Client Upload File Size = 000E1012 Bytes at 80300000

Success!
<RealTek>
Root filesystem upgrade.
checksum Ok !
burn Addr =0x00100000! srcAddr=0x80300010 len =0x000e1000
...............
Flash Write Successed!
<RealTek>
**TFTP Client Upload, File Name: linux.bin
\
**TFTP Client Upload File Size = 000CF012 Bytes at 80300000

Success!

<RealTek>
Linux kernel upgrade.
checksum Ok !
burn Addr =0x00010000! srcAddr=0x80300000 len =0x000cf012
.............
Flash Write Successed!
<RealTek>
reboot.......

UART1 output test ok
Uart init
mfid=000000c2 devid=00002249
Found 1 x 2M flash memory

---RealTek(RTL8186)at 2005.09.14-18:49+0800 version 1.3b [32bit](180MHz)
Jump to image start=0x80300000...
early printk enabled
Determined physical RAM map:
memory: 04000000 @ 00000000 (usable)
Initial ramdisk at: 0x80239000 (22522 bytes)
On node 0 totalpages: 16384

After checking the sources I think it's unlikely that it is because the serial console problem. It's likely that the system has gottened into unrecoverable state running certain code dealling with paging and/or memory. Otherwise, it should at least print "Kernel commandl line ....".

Cheers.