Julius Werner 487f7f24a5 arm64: mmu: Spot check security state for TTB mapping
Since commit 372d0ff1d1 (arch/arm64: mmu: Spot check TTB memory
attributes), we already check the memory attributes that the TTB region
is mapped with to avoid configuration mistakes that cause weird issues
(because the MMU walks the page tables with different memory attributes
than they were written with). Unfortunately, we only checked
cachability, but the security state attribute is just as important for
this (because it is part of the cache tag, meaning that a cache entry
created by accessing the non-secure mapping won't be used when trying to
read the same address through a secure mapping... and since AArch64 page
table walks are cache snooping and we rely on that behavior, this can
lead to the MMU not seeing the new page table entries we just wrote).

This patch adds the check for security state and cleans up that code a
little.

Change-Id: I70cda4f76f201b03d69a9ece063a3830b15ac04b
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/28017
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
2018-08-13 12:24:56 +00:00
2016-10-29 01:35:03 +02:00
2012-11-01 23:13:39 +01:00
2006-08-12 22:03:36 +00:00
2017-06-27 17:04:32 +00:00

-------------------------------------------------------------------------------
coreboot README
-------------------------------------------------------------------------------

coreboot is a Free Software project aimed at replacing the proprietary BIOS
(firmware) found in most computers.  coreboot performs a little bit of
hardware initialization and then executes additional boot logic, called a
payload.

With the separation of hardware initialization and later boot logic,
coreboot can scale from specialized applications that run directly
firmware, run operating systems in flash, load custom
bootloaders, or implement firmware standards, like PC BIOS services or
UEFI. This allows for systems to only include the features necessary
in the target application, reducing the amount of code and flash space
required.

coreboot was formerly known as LinuxBIOS.


Payloads
--------

After the basic initialization of the hardware has been performed, any
desired "payload" can be started by coreboot.

See https://www.coreboot.org/Payloads for a list of supported payloads.


Supported Hardware
------------------

coreboot supports a wide range of chipsets, devices, and mainboards.

For details please consult:

 * https://www.coreboot.org/Supported_Motherboards
 * https://www.coreboot.org/Supported_Chipsets_and_Devices


Build Requirements
------------------

 * make
 * gcc / g++
   Because Linux distribution compilers tend to use lots of patches. coreboot
   does lots of "unusual" things in its build system, some of which break due
   to those patches, sometimes by gcc aborting, sometimes - and that's worse -
   by generating broken object code.
   Two options: use our toolchain (eg. make crosstools-i386) or enable the
   ANY_TOOLCHAIN Kconfig option if you're feeling lucky (no support in this
   case).
 * iasl (for targets with ACPI support)
 * pkg-config
 * libssl-dev (openssl)

Optional:

 * doxygen (for generating/viewing documentation)
 * gdb (for better debugging facilities on some targets)
 * ncurses (for 'make menuconfig' and 'make nconfig')
 * flex and bison (for regenerating parsers)


Building coreboot
-----------------

Please consult https://www.coreboot.org/Build_HOWTO for details.


Testing coreboot Without Modifying Your Hardware
------------------------------------------------

If you want to test coreboot without any risks before you really decide
to use it on your hardware, you can use the QEMU system emulator to run
coreboot virtually in QEMU.

Please see https://www.coreboot.org/QEMU for details.


Website and Mailing List
------------------------

Further details on the project, a FAQ, many HOWTOs, news, development
guidelines and more can be found on the coreboot website:

  https://www.coreboot.org

You can contact us directly on the coreboot mailing list:

  https://www.coreboot.org/Mailinglist


Copyright and License
---------------------

The copyright on coreboot is owned by quite a large number of individual
developers and companies. Please check the individual source files for details.

coreboot is licensed under the terms of the GNU General Public License (GPL).
Some files are licensed under the "GPL (version 2, or any later version)",
and some files are licensed under the "GPL, version 2". For some parts, which
were derived from other projects, other (GPL-compatible) licenses may apply.
Please check the individual source files for details.

This makes the resulting coreboot images licensed under the GPL, version 2.
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