PT_GNU_EH_FRAME semantics

[<heliosc at mindspring dot com>]

Hi, my name is Rayiner Hashem. I've been working on writing an ELF loader (for
use in a kernel) that will handle all of gcc generated code, including C++
exceptions. I'm having a little trouble figuring out the purpose and semantics
of the PT_GNU_EH_FRAME load flag. From what I gather, its there to allow the
EH frames to stay unloaded until an exception actually occurs. According to
posts on this mailing list, the linker is supposed to sort the eh_frame
sections in the object files and stuff them into a program segment and flag it
with PT_GNU_EH_FRAME. Is this description even close to being on track? I
would appreciate it if someone could give at least a general idea of how this
works, so I know what to look out for when wading through ld. 

PS> Is there anybody out there documenting all this? GCC used to be the most
well-documented compiler out there, but much of the current stuff isn't even
applicable anymore. Maybe after the flurry of activity with respect to C++ is
over?