OpenE2K/qemu-e2k
13
4
Fork 0
Code Issues 4 Pull Requests Projects 2 Releases Activity

docs/system/arm/virt.rst: Improve 'highmem' option docs

Browse Source 
Improve the 'highmem' option docs to note that by default we assume
that a 32-bit kernel on an LPAE-capable CPU has LPAE enabled, and
what the consequences are.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Message-id: 20240109170834.1387457-1-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2024-01-09 17:08:34 +00:00
parent 71e269fb7b
commit 8cf1da7291
1 changed files with 7 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
docs/system/arm/virt.rst
View File

@ -96,7 +96,13 @@ mte
highmem
Set ``on``/``off`` to enable/disable placing devices and RAM in physical
address space above 32 bits. The default is ``on`` for machine types
later than ``virt-2.12``.
later than ``virt-2.12`` when the CPU supports an address space
bigger than 32 bits (i.e. 64-bit CPUs, and 32-bit CPUs with the
Large Physical Address Extension (LPAE) feature). If you want to
boot a 32-bit kernel which does not have ``CONFIG_LPAE`` enabled on
a CPU type which implements LPAE, you will need to manually set
this to ``off``; otherwise some devices, such as the PCI controller,
will not be accessible.
compact-highmem
Set ``on``/``off`` to enable/disable the compact layout for high memory regions.