From: "Bryan O'Donoghue" <pure.logic@nexus-software.ie>
To: Pavel Machek <pavel@ucw.cz>
Cc: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com,
x86@kernel.org, dvhart@infradead.org, andy.shevchenko@gmail.com,
boon.leong.ong@intel.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 1/1] x86: Add Isolated Memory Regions for Quark X1000
Date: Tue, 24 Feb 2015 22:40:15 +0000 [thread overview]
Message-ID: <54ECFDCF.8040902@nexus-software.ie> (raw)
In-Reply-To: <20150223221847.GA5285@amd>
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.
next prev parent reply other threads:[~2015-02-24 22:40 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-26 14:15 [PATCH v3 0/1] x86: Add IMR support to Quark/Galileo Bryan O'Donoghue
2015-01-26 14:15 ` [PATCH v3 1/1] x86: Add Isolated Memory Regions for Quark X1000 Bryan O'Donoghue
2015-01-26 16:37 ` Andy Shevchenko
2015-01-26 16:43 ` Andy Shevchenko
2015-01-26 16:59 ` Bryan O'Donoghue
2015-01-26 17:23 ` Andy Shevchenko
2015-01-26 18:02 ` Bryan O'Donoghue
2015-01-26 18:04 ` Bryan O'Donoghue
2015-02-23 22:18 ` Pavel Machek
2015-02-24 22:40 ` Bryan O'Donoghue [this message]
2015-03-02 12:19 ` Pavel Machek
2015-01-26 14:37 ` [PATCH v3 0/1] x86: Add IMR support to Quark/Galileo Bryan O'Donoghue
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