Kconfig
# SPDX-License-Identifier: GPL-2.0
config NIOS2
def_bool y
select ARCH_HAS_SYNC_DMA_FOR_CPU
select ARCH_HAS_SYNC_DMA_FOR_DEVICE
select ARCH_NO_SWAP
select DMA_DIRECT_OPS
select TIMER_OF
select GENERIC_ATOMIC64
select GENERIC_CLOCKEVENTS
select GENERIC_CPU_DEVICES
select GENERIC_IRQ_PROBE
select GENERIC_IRQ_SHOW
select GENERIC_STRNCPY_FROM_USER
select GENERIC_STRNLEN_USER
select HAVE_ARCH_TRACEHOOK
select HAVE_ARCH_KGDB
select IRQ_DOMAIN
select MODULES_USE_ELF_RELA
select OF
select OF_EARLY_FLATTREE
select SOC_BUS
select SPARSE_IRQ
select USB_ARCH_HAS_HCD if USB_SUPPORT
select CPU_NO_EFFICIENT_FFS
select ARCH_DISCARD_MEMBLOCK
config GENERIC_CSUM
def_bool y
config GENERIC_HWEIGHT
def_bool y
config GENERIC_CALIBRATE_DELAY
def_bool y
config NO_IOPORT_MAP
def_bool y
config HAS_DMA
def_bool y
config FPU
def_bool n
config RWSEM_GENERIC_SPINLOCK
def_bool y
config TRACE_IRQFLAGS_SUPPORT
def_bool n
menu "Kernel features"
source "kernel/Kconfig.hz"
config FORCE_MAX_ZONEORDER
int "Maximum zone order"
range 9 20
default "11"
help
The kernel memory allocator divides physically contiguous memory
blocks into "zones", where each zone is a power of two number of
pages. This option selects the largest power of two that the kernel
keeps in the memory allocator. If you need to allocate very large
blocks of physically contiguous memory, then you may need to
increase this value.
This config option is actually maximum order plus one. For example,
a value of 11 means that the largest free memory block is 2^10 pages.
endmenu
source "arch/nios2/platform/Kconfig.platform"
menu "Processor type and features"
config MMU
def_bool y
config NR_CPUS
int
default "1"
config NIOS2_ALIGNMENT_TRAP
bool "Catch alignment trap"
default y
help
Nios II CPUs cannot fetch/store data which is not bus aligned,
i.e., a 2 or 4 byte fetch must start at an address divisible by
2 or 4. Any non-aligned load/store instructions will be trapped and
emulated in software if you say Y here, which has a performance
impact.
comment "Boot options"
config CMDLINE_BOOL
bool "Default bootloader kernel arguments"
default y
config CMDLINE
string "Default kernel command string"
default ""
depends on CMDLINE_BOOL
help
On some platforms, there is currently no way for the boot loader to
pass arguments to the kernel. For these platforms, you can supply
some command-line options at build time by entering them here. In
other cases you can specify kernel args so that you don't have
to set them up in board prom initialization routines.
config CMDLINE_FORCE
bool "Force default kernel command string"
depends on CMDLINE_BOOL
help
Set this to have arguments from the default kernel command string
override those passed by the boot loader.
config NIOS2_CMDLINE_IGNORE_DTB
bool "Ignore kernel command string from DTB"
depends on CMDLINE_BOOL
depends on !CMDLINE_FORCE
default y
help
Set this to ignore the bootargs property from the devicetree's
chosen node and fall back to CMDLINE if nothing is passed.
config NIOS2_PASS_CMDLINE
bool "Passed kernel command line from u-boot"
default n
help
Use bootargs env variable from u-boot for kernel command line.
will override "Default kernel command string".
Say N if you are unsure.
config NIOS2_BOOT_LINK_OFFSET
hex "Link address offset for booting"
default "0x00500000"
help
This option allows you to set the link address offset of the zImage.
This can be useful if you are on a board which has a small amount of
memory.
endmenu
menu "Advanced setup"
config ADVANCED_OPTIONS
bool "Prompt for advanced kernel configuration options"
comment "Default settings for advanced configuration options are used"
depends on !ADVANCED_OPTIONS
config NIOS2_KERNEL_MMU_REGION_BASE_BOOL
bool "Set custom kernel MMU region base address"
depends on ADVANCED_OPTIONS
help
This option allows you to set the virtual address of the kernel MMU region.
Say N here unless you know what you are doing.
config NIOS2_KERNEL_MMU_REGION_BASE
hex "Virtual base address of the kernel MMU region " if NIOS2_KERNEL_MMU_REGION_BASE_BOOL
default "0x80000000"
help
This option allows you to set the virtual base address of the kernel MMU region.
config NIOS2_KERNEL_REGION_BASE_BOOL
bool "Set custom kernel region base address"
depends on ADVANCED_OPTIONS
help
This option allows you to set the virtual address of the kernel region.
Say N here unless you know what you are doing.
config NIOS2_KERNEL_REGION_BASE
hex "Virtual base address of the kernel region " if NIOS2_KERNEL_REGION_BASE_BOOL
default "0xc0000000"
config NIOS2_IO_REGION_BASE_BOOL
bool "Set custom I/O region base address"
depends on ADVANCED_OPTIONS
help
This option allows you to set the virtual address of the I/O region.
Say N here unless you know what you are doing.
config NIOS2_IO_REGION_BASE
hex "Virtual base address of the I/O region" if NIOS2_IO_REGION_BASE_BOOL
default "0xe0000000"
endmenu