zephyr/misc/Kconfig

366 lines
10 KiB
Plaintext

# Kconfig - miscellany configuration options
#
# Copyright (c) 2014-2015 Wind River Systems, Inc.
#
# SPDX-License-Identifier: Apache-2.0
#
menu "Compile and Link Features"
menu "Linker Options"
config HAS_FLASH_LOAD_OFFSET
bool
help
This option is selected by targets having a FLASH_LOAD_OFFSET
and FLASH_LOAD_SIZE.
config FLASH_LOAD_OFFSET
hex "Kernel load offset"
default 0
depends on HAS_FLASH_LOAD_OFFSET
help
This option specifies the byte offset from the beginning of flash that
the kernel should be loaded into. Changing this value from zero will
affect the Zephyr image's link, and will decrease the total amount of
flash available for use by application code.
If unsure, leave at the default value 0.
config FLASH_LOAD_SIZE
hex "Kernel load size"
default 0
depends on HAS_FLASH_LOAD_OFFSET
help
If non-zero, this option specifies the size, in bytes, of the flash
area that the Zephyr image will be allowed to occupy. If zero, the
image will be able to occupy from the FLASH_LOAD_OFFSET to the end of
the device.
If unsure, leave at the default value 0.
config TEXT_SECTION_OFFSET
hex "TEXT section offset"
default 0
help
This sets and offset before the text section and allows booting images
with custom headers that are inserted at the beginning of the image.
config HAVE_CUSTOM_LINKER_SCRIPT
prompt "Custom linker scripts provided"
def_bool n
help
Set this option if you have a custom linker script which needed to
be define in CUSTOM_LINKER_SCRIPT.
config CUSTOM_LINKER_SCRIPT
string "Path to custom linker script"
default ""
depends on HAVE_CUSTOM_LINKER_SCRIPT
help
Path to the linker script to be used instead of the one define by the
board.
The linker script must be based on a version provided by Zephyr since
the kernel can expect a certain layout/certain regions.
This is useful when an application needs to add sections into the
linker script and avoid having to change the script provided by
Zephyr.
config CUSTOM_RODATA_LD
bool "Include custom-rodata.ld"
default n
help
Include a customized linker script fragment for inserting additional
data and linker directives into the rodata section.
config CUSTOM_RWDATA_LD
bool "Include custom-rwdata.ld"
default n
help
Include a customized linker script fragment for inserting additional
data and linker directives into the data section.
config CUSTOM_SECTIONS_LD
bool "Include custom-sections.ld"
default n
help
Include a customized linker script fragment for inserting additional
arbitrary sections.
config LINK_WHOLE_ARCHIVE
bool "Allow linking with --whole-archive"
default n
help
This options allows linking external libraries with the
--whole-archive option to keep all symbols.
endmenu
menu "Compiler Options"
config CROSS_COMPILE
string "Cross-compiler tool prefix"
help
Same as running 'make CROSS_COMPILE=prefix-' but stored for
default make runs in this kernel build directory. You don't
need to set this unless you want the configured kernel build
directory to select the cross-compiler automatically.
config COMPILER_OPT
string
prompt "Custom compiler options"
default ""
help
This option is a free-form string that is passed to the compiler
when building all parts of a project (i.e. kernel).
The compiler options specified by this string supplement the
predefined set of compiler supplied by the build system,
and can be used to change compiler optimization, warning and error
messages, and so on.
config TOOLCHAIN_VARIANT
string "Cross-compiler variant name"
help
For optimized compilers with reduced features, specify the name
of the variant.
endmenu
config CPLUSPLUS
bool "Enable C++ support for the application"
default n
help
This option enables the use of applications built with C++.
config GDB_INFO
bool
prompt "Task-aware debugging with GDB"
default n
help
This option enables the kernel to collect additional information
during interrupts, exceptions, and context switches. This information
is required for task-aware debugging with GDB.
config KERNEL_BIN_NAME
string "The kernel binary name"
default "zephyr"
help
This option sets the name of the generated kernel binary.
endmenu
menu "Debugging Options"
config DEBUG
bool "Build kernel with debugging enabled"
default n
help
Build a kernel suitable for debugging. Right now, this option
only disables optimization, more debugging variants can be selected
from here to allow more debugging.
config STACK_USAGE
bool "Generate stack usage information"
default n
help
Generate an extra file that specifies the maximum amount of stack used,
on a per-function basis.
config PRINTK
bool
prompt "Send printk() to console"
depends on CONSOLE_HAS_DRIVER
default y
help
This option directs printk() debugging output to the supported
console device, rather than suppressing the generation
of printk() output entirely. Output is sent immediately, without
any mutual exclusion or buffering.
config STDOUT_CONSOLE
bool
prompt "Send stdout to console"
depends on CONSOLE_HAS_DRIVER
default n
help
This option directs standard output (e.g. printf) to the console
device, rather than suppressing it entirely.
config EARLY_CONSOLE
bool
prompt "Send stdout at the earliest stage possible"
default n
help
This option will enable stdout as early as possible, for debugging
purpose. For instance, in case of STDOUT_CONSOLE being set it will
initialize its driver earlier than normal, in order to get the stdout
sent through the console at the earliest stage possible.
config ASSERT
bool
prompt "Enable __ASSERT() macro"
default n
help
This enables the __ASSERT() macro in the kernel code. If an assertion
fails, the calling thread is put on an infinite tight loop. Since
enabling this adds a significant footprint, it should only be enabled
in a non-production system.
config ASSERT_LEVEL
int
prompt "__ASSERT() level"
default 2
range 0 2
depends on ASSERT
help
This option specifies the assertion level used by the __ASSERT()
macro. It can be set to one of three possible values:
Level 0: off
Level 1: on + warning in every file that includes __assert.h
Level 2: on + no warning
config DEBUG_TRACING_KERNEL_OBJECTS
bool "Kernel object tracing (deprecated)"
select OBJECT_TRACING
default n
help
For backward compatibility only
config OBJECT_TRACING
bool
prompt "Kernel object tracing"
default n
help
This option enable the feature for tracing kernel objects. This option
is for debug purposes and increases the memory footprint of the kernel.
config OVERRIDE_FRAME_POINTER_DEFAULT
bool
prompt "Override compiler defaults for -fomit-frame-pointer"
default n
help
Omitting the frame pointer prevents the compiler from putting the stack
frame pointer into a register. Saves a few instructions in function
prologues/epilogues and frees up a register for general-purpose use,
which can provide good performance improvements on register-constrained
architectures like x86. On some architectures (including x86) omitting
frame pointers impedes debugging as local variables are harder to
locate. At -O1 and above gcc will enable -fomit-frame-pointer
automatically but only if the architecture does not require if for
effective debugging.
Choose Y if you want to override the default frame pointer behavior
of your compiler, otherwise choose N.
config OMIT_FRAME_POINTER
bool
prompt "Omit frame pointer"
default n
depends on OVERRIDE_FRAME_POINTER_DEFAULT
help
Choose Y for best performance. On some architectures (including x86)
this will favor code size and performance over debugability.
Choose N in you wish to retain the frame pointer. This option may
be useful if your application uses runtime backtracing and does not
support parsing unwind tables.
If unsure, disable OVERRIDE_FRAME_POINTER_DEFAULT to allow the compiler
to adopt sensible defaults for your architecture.
endmenu
menu "System Monitoring Options"
config PERFORMANCE_METRICS
bool
prompt "Enable performance metrics [EXPERIMENTAL]"
default n
help
Enable Performance Metrics.
config BOOT_TIME_MEASUREMENT
bool
prompt "Boot time measurements [EXPERIMENTAL]"
default n
depends on PERFORMANCE_METRICS
help
This option enables the recording of timestamps during system start
up. The global variable __start_tsc records the time kernel begins
executing, while __main_tsc records when main() begins executing,
and __idle_tsc records when the CPU becomes idle. All values are
recorded in terms of CPU clock cycles since system reset.
config CPU_CLOCK_FREQ_MHZ
int
prompt "CPU CLock Frequency in MHz"
default 20
depends on BOOT_TIME_MEASUREMENT
help
This option specifies the CPU Clock Frequency in MHz in order to
convert Intel RDTSC timestamp to microseconds.
endmenu
menu "Boot Options"
config IS_BOOTLOADER
bool "Act as a bootloader"
default n
depends on XIP
depends on ARM
help
This option indicates that Zephyr will act as a bootloader to execute
a separate Zephyr image payload.
config BOOTLOADER_SRAM_SIZE
int "SRAM reserved for when Zephyr acts as a bootloader"
default 16
depends on !XIP || IS_BOOTLOADER
depends on ARM
help
This option specifies the amount of SRAM (measure in kB) reserved for
when Zephyr is to act as a bootloader.
config BOOTLOADER_KEXEC
bool
prompt "Boot using Linux kexec() system call"
depends on X86
default n
help
This option signifies that Linux boots the kernel using kexec system call
and utility. This method is used to boot the kernel over the network.
config BOOTLOADER_UNKNOWN
bool
prompt "Generic boot loader support"
default n
depends on X86
help
This option signifies that the target has a generic bootloader
or that it supports multiple ways of booting and it isn't clear
at build time which method is to be used. When this option is enabled
the board may have to do extra work to ensure a proper startup.
config BOOTLOADER_CONTEXT_RESTORE
bool
prompt "Boot loader has context restore support"
default y
depends on SYS_POWER_DEEP_SLEEP && BOOTLOADER_CONTEXT_RESTORE_SUPPORTED
help
This option signifies that the target has a bootloader
that restores CPU context upon resuming from deep sleep
power state.
config REBOOT
bool "Reboot functionality"
default n
select SYSTEM_CLOCK_DISABLE
help
Enable the sys_reboot() API. Enabling this can drag in other subsystems
needed to perform a "safe" reboot (e.g. SYSTEM_CLOCK_DISABLE, to stop the
system clock before issuing a reset).
endmenu