Relevant references:
   http://www.tldp.org/HOWTO/KernelAnalysis-HOWTO-5.html#ss5.1%22 

The initial stack and register settings are from pages 54 and 55 of the i386 ABI

PDF documentation is available at:
http://www.x86-64.org/documentation/

Different ABI specs are available for each processor and operating system.

As part of a general stack frame issue there is a red zone defined on page 16:
   The 128-byte area beyond the location pointed to by %rsp is considered to
be reserved and shall not be modified by signal or interrupt handlers.8 Therefore,
functions may use this area for temporary data that is not needed across function
calls. In particular, leaf functions may use this area for their entire stack frame,
rather than adjusting the stack pointer in the prologue and epilogue. This area is
known as the red zone.

More information specific to PowerPC is available at:
   http://www-01.ibm.com/chips/techlib/techlib.nsf/techdocs/852569B20050FF7785256996007558C6/$file/cwg.pdf

Location of Intel Processor Manuals: http://www.intel.com/products/processor/manuals

