How the kernel printk works before do console_setup.

[Johnny Hung]

Hi All:
    I have a powerpc arch platform. The default console is ttyS1 not
ttyS0 in the platform. My question is how the kernel print debug
message
like DBG before parse kernel command line and do console_setup
function. The command line passed to kernel about console info is
console=ttyS1.
So kernel can not print anything before parse cmd line and initial
console but the result is against. Anyone point me or give me a clue
is appreciate.

BR, H. Johnny