From 72a1bcfc28a6bc9afbd50dd3fc4c76d5aed44812 Mon Sep 17 00:00:00 2001 From: Benjamin Kaduk Date: Fri, 28 Jul 2017 21:22:11 +0000 Subject: [PATCH] Add 2017Q2 arm64 entry from andrew --- .../news/status/report-2017-04-2017-06.xml | 55 +++++++++++++++++++ 1 file changed, 55 insertions(+) diff --git a/en_US.ISO8859-1/htdocs/news/status/report-2017-04-2017-06.xml b/en_US.ISO8859-1/htdocs/news/status/report-2017-04-2017-06.xml index b4fc8ec2c0..35666a3872 100644 --- a/en_US.ISO8859-1/htdocs/news/status/report-2017-04-2017-06.xml +++ b/en_US.ISO8859-1/htdocs/news/status/report-2017-04-2017-06.xml @@ -1699,4 +1699,59 @@ and net/coda_server). + + + &os;/arm64 + + + + + Andrew + Turner + + andrew@FreeBSD.org + + + + + &os; arm64 Wiki Page + + + +

Support for the Privilege Access Never (PAN) feature was + added. This stops the kernel from accessing userspace + memory, except through specific instructions. This helps + security by only allowing access to userspace via the + correct accessor functions. This is enabled on all + supported CPUs that implement ARMv8.1 or later.

+ +

The pmap code now supports the Unprivileged + execute-never (UXN) and Privileged execute-never (PXN) bits + in the page tables. These bits stop userspace and the + kernel, respectively, from executing instructions on any + marked page.

+ +

The performance of the pmap layer has been improved. Many + of the cache handling function calls have been removed. + Some were needed early on to work around other bugs that + have now been fixed. The removal of these calls has led to + a large performance improvement.

+ +

The kernel now uses crc32c instructions where + appropriate. These are an optional set of instructions to + perform crc32c quickly without using a lookup + table.c

+ +

The VM_MEMATTR_WRITE_THROUGH memory attribute is + now supported. This is used to allocate memory for the + framebuffer. Previously, the kernel would use cached + memory; however, this leads to visual artifacts. The + write-through flag fixes these by writing data out to + RAM.

+ +

The default linker on arm64 is now lld. This + means &os; is able to built itsself with just the components + in the base system, a big milestone!

+ +