- whole nvram was erased in some conditions
- fix out of range accesses
- improve reading speed by keeping contents in memory
- rename capacity to chip_size
(Hervé Poussineau)
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4051 c046a42c-6fe2-441c-8c8c-71466251a162