Messages in this thread | | | Date | Mon, 2 Mar 2015 13:19:19 +0100 | From | Pavel Machek <> | Subject | Re: [PATCH v3 1/1] x86: Add Isolated Memory Regions for Quark X1000 |
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On Tue 2015-02-24 22:40:15, Bryan O'Donoghue wrote: > On 23/02/15 22:18, Pavel Machek wrote: > >On Mon 2015-01-26 14:15:27, Bryan O'Donoghue wrote: > > > > >Do the applications normally need to manipulate IMRs? > > > Applications could in theory manipulate IMRs - you might want to place an > IMR around an EFI capsule in memory for example - before calling a capsule > update. > > This code will place an IMR around the kernel .text - .rodata which ensures > that no unwarranted DMA access can rewrite write-only kernel addresses - > something the MMU would not fault on - on non-IMR enabled processors. > > >Would it be > >possible to do all IMR manipulations in the bootloader? > > > > Possible yes - in practical terms for Galileo or the SMARC+Quark from > Kontron for example - you'd be forcing a bootloader change - which most > users will not pick up. > > > Considering IMRs can reset the system if they aren't sanitized, it's good > practice for the kernel to go and make sure that every unlocked IMR is > torn-down and reset.
Ok, makes sense. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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