On Fri, Jan 29, 2016 at 10:22:34AM -0300, Ezequiel Garcia wrote: > On 28 January 2016 at 16:48, Brian Norris <[email protected]> wrote: > > On Thu, Jan 28, 2016 at 04:24:50PM -0300, Ezequiel Garcia wrote: > >> How about this: > >> > >> 1) ioctl(MEMLOCK) the entire flash (SR_SRWD is set) > >> 2) ioctl(MEMUNLOCK) partially (SW_SRWD keeps set) > >> 3) ioctl(MEMLOCK) the entire flash again
... > >> but would (3) be allowed given > >> SW_SRWD is set? > > > > Yes, if /WP=1 (high). > > > > Right. So, after giving some more thought do this, I'd say it might > make sense to clear SRWD only when unlocking the entire flash. If > anything else, it would allow a path to disable hardware protection on > the lock range? Yes, that sounds fine to me, as it does allow removal of the HW protection. So one could, for example, do: 0. bring /WP=1 (high) 1. unlock the whole flash 2. bring /WP=0 (low) -- flash is still unlocked 3. allow a one-time relocking of the flash via MEMLOCK 4. no more locking changes I'll send out v2. Brian
