CONFIG_KERNEL_VM_OFFSET¶
Kernel offset within address space
Type: hex
Help¶
Offset that the kernel image begins within its address space,
if this is not the same offset from the beginning of RAM.
Some care may need to be taken in selecting this value. In certain
build-time cases, or when a physical address cannot be looked up
in page tables, the equation:
virt = phys + ((KERNEL_VM_BASE + KERNEL_VM_OFFSET) -
(SRAM_BASE_ADDRESS + SRAM_OFFSET))
Will be used to convert between physical and virtual addresses for
memory that is mapped at boot.
This uncommon and is only necessary if the beginning of VM and
physical memory have dissimilar alignment.
Kconfig definitions¶
At <Zephyr>/arch/x86/Kconfig:190
Included via <Zephyr>/Kconfig:8 → <Zephyr>/Kconfig.zephyr:37 → <Zephyr>/arch/Kconfig:12
Menu path: (Top) → X86 Architecture Options
config KERNEL_VM_OFFSET
hex
default 0x100000 if MMU
depends on X86
At <Zephyr>/arch/Kconfig:642
Included via <Zephyr>/Kconfig:8 → <Zephyr>/Kconfig.zephyr:37
Menu path: (Top) → Enable MMU features
config KERNEL_VM_OFFSET
hex "Kernel offset within address space"
default 0
depends on MMU
help
Offset that the kernel image begins within its address space,
if this is not the same offset from the beginning of RAM.
Some care may need to be taken in selecting this value. In certain
build-time cases, or when a physical address cannot be looked up
in page tables, the equation:
virt = phys + ((KERNEL_VM_BASE + KERNEL_VM_OFFSET) -
(SRAM_BASE_ADDRESS + SRAM_OFFSET))
Will be used to convert between physical and virtual addresses for
memory that is mapped at boot.
This uncommon and is only necessary if the beginning of VM and
physical memory have dissimilar alignment.
(The ‘depends on’ condition includes propagated dependencies from ifs and menus.)