:orphan:

.. title:: CONFIG_X86_EXTRA_PAGE_TABLE_PAGES

.. kconfig:: CONFIG_X86_EXTRA_PAGE_TABLE_PAGES

CONFIG_X86_EXTRA_PAGE_TABLE_PAGES
#################################

*Reserve extra pages in page table*

Type: ``int``

Help
====

.. code-block:: none

    The whole page table is pre-allocated at build time and is
    dependent on the range of address space. This allows reserving
    extra pages (of size CONFIG_MMU_PAGE_SIZE) to the page table
    so that gen_mmu.py can make use of these extra pages.

    Says 0 unless absolutely sure that this is necessary.

Direct dependencies
===================

\ :kconfig:`BOARD_QEMU_X86_TINY <CONFIG_BOARD_QEMU_X86_TINY>` || (\ :kconfig:`X86_MMU <CONFIG_X86_MMU>` && \ :kconfig:`X86 <CONFIG_X86>`)

*(Includes any dependencies from ifs and menus.)*

Defaults
========

- 2 if \ :kconfig:`DEMAND_PAGING <CONFIG_DEMAND_PAGING>` && !\ :kconfig:`LINKER_GENERIC_SECTIONS_PRESENT_AT_BOOT <CONFIG_LINKER_GENERIC_SECTIONS_PRESENT_AT_BOOT>`
- 1 if \ :kconfig:`X86_PAE <CONFIG_X86_PAE>` && \ :kconfig:`KERNEL_VM_BASE <CONFIG_KERNEL_VM_BASE>` != \ :kconfig:`SRAM_BASE_ADDRESS <CONFIG_SRAM_BASE_ADDRESS>`
- 0

Kconfig definitions
===================



At ``<Zephyr Boards>/x86/qemu_x86/Kconfig.defconfig:103``

Included via ``Kconfig:8`` → ``Kconfig.zephyr:22``

Menu path: (Top)

.. code-block:: kconfig

    config X86_EXTRA_PAGE_TABLE_PAGES
    	int
    	default 2 if DEMAND_PAGING && !LINKER_GENERIC_SECTIONS_PRESENT_AT_BOOT
    	depends on BOARD_QEMU_X86_TINY

----

At ``<Zephyr Architecture>/x86/Kconfig:370``

Included via ``Kconfig:8`` → ``Kconfig.zephyr:39`` → ``<Zephyr Architecture>/Kconfig:12``

Menu path: (Top) → X86 Architecture Options

.. code-block:: kconfig

    config X86_EXTRA_PAGE_TABLE_PAGES
    	int "Reserve extra pages in page table"
    	default 1 if X86_PAE && KERNEL_VM_BASE != SRAM_BASE_ADDRESS
    	default 0
    	depends on X86_MMU && X86
    	help
    	  The whole page table is pre-allocated at build time and is
    	  dependent on the range of address space. This allows reserving
    	  extra pages (of size CONFIG_MMU_PAGE_SIZE) to the page table
    	  so that gen_mmu.py can make use of these extra pages.
	  
    	  Says 0 unless absolutely sure that this is necessary.

*(The 'depends on' condition includes propagated dependencies from ifs and menus.)*