is there any docs/manuals for linker scripts symbols

[<ik@cyberspace.org>]

Hi All,

Is there any documentation for the symbols in the ld.script linker
scripts for the linux kernel. 

I'm porting Linux kernel to a mips board for which I need to understand
the various symbols used in the kernel.

For example what is the use of the following symbols
`__init_begin'
`__init_end'
`__initcall_start
`__initcall_end'
`_ftext'
`__setup_start'
`__setup_end'

I'm not good in these linker scripts... any help pointers would be of
great help to me ! (I'm referrring gnu ld  manual pages ... still have a
long way to go :(

Thanks in advance !
Indu