Binary config and fork() ...

[shenson@nyx10.cs.du.edu (Stephen Henson)]

	Yes you can use the symbol table to implement binary configuration,
that's what my (unreleased) Minixfs binary config program does. It also why
I originally wrote nlist(). I think with arrays you can't really increase
their length safely by fiddling with the reloc table (what if the compiler
or code uses an offset as an optimisation to acces a later variable?). Anyway
I've written a short file which gives the basic idea and I'll send it when
I've checked out a couple of sample programs.
	Re non-blocking fork(). I think this could cause problems. At present
(or as far as I can gather without mem protection on my STE) the virtual
addresses are always the same as the physical ones. If you change this (and
it is compulsory for fork()) then you get DMA problems. E.g. suppose I make
a call to Fread. What address should the OS pass down? If the data is to be read
directly into the buffer via DMA then you need to pass the physical address, if
it goes via a cache you need the virtual address. If the hard disk software
uses an internal cache then it's even more fun ...
Steve.