A simple question about FreeBSD-ARM, thanks for reply

[PowerMan]

Dear sir or Madam:

    My first language is not English, please forgive me if I made
some bad expression or words.

    I am an embedded system engineer, I use ARM920T and linux in
my projects. I am familiar with ARM architecture and linux device
driver.

    Now I intend to study the principle of OS, but I find the linux
kernel is too large and complex, so I change to FreeBSD.

    Would the FreeBSD-ARM be very complex? How many lines would the
source code of the kernel (without device drivers, just the key modules
like FS, MM, porcess scheduler, TCP/IP and the others) be?

    I hope I could make some contribution to FreeBSD-ARM, to compete with
other OS like linux and vxWork (they are used widely in PR.China).

    It is nice of you to reply me. I would be admiring to receive your
reply.
Thank you.