zephyr/subsys/debug/Kconfig

# Kconfig - debug configuration options

#
# Copyright (c) 2015 Wind River Systems, Inc.
#
# SPDX-License-Identifier: Apache-2.0
#

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 STACK_SENTINEL
	bool "Enable stack sentinel"
	default n
	select THREAD_STACK_INFO
	depends on !USERSPACE
	help
	  Store a magic value at the lowest addresses of a thread's stack.
	  Periodically check that this value is still present and kill the
	  thread gracefully if it isn't. This is currently checked in four
	  places:

	  1) Upon any context switch for the outgoing thread
	  2) Any hardware interrupt that doesn't context switch, the check is
	     performed for the interrupted thread
	  3) When a thread returns from its entry point
	  4) When a thread calls k_yield() but doesn't context switch

	  This feature doesn't prevent corruption and the system may be
	  in an unusable state. However, given the bizarre behavior associated
	  with stack overflows, knowledge that this is happening is very
	  useful.

	  This feature is intended for those systems which lack hardware support
	  for stack overflow protection, or have insufficient system resources
	  to use that hardware support.

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 PRINTK_BUFFER_SIZE
	int
	prompt "printk() buffer size"
	depends on PRINTK
	depends on USERSPACE
	default 32
	help
	  If userspace is enabled, printk() calls are buffered so that we do
	  not have to make a system call for every character emitted. Specify
	  the size of this buffer.

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 y if TEST
	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 FORCE_NO_ASSERT
	bool
	prompt "Force-disable no assertions"
	default n
	help
	  This boolean option disables Zephyr assertion testing even
	  in circumstances (sanitycheck) where it is enabled via
	  CFLAGS and not Kconfig.  Added solely to be able to work
	  around compiler bugs for specific tests.

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.


#
# Generic Debugging Options
#
config DEBUG_INFO
	bool "Enable system debugging information"
	default n
	help
	  This option enables the addition of various information that can be
	  used by debuggers in debugging the system, or enable additional
	  debugging information to be reported at runtime.

config EXCEPTION_STACK_TRACE
	bool "Attempt to print stack traces upon exceptions"
	default y
	depends on PRINTK
	depends on DEBUG_INFO
	depends on !OMIT_FRAME_POINTER
	help
	  If the architecture fatal handling code supports it, attempt to
	  print a stack trace of function memory addresses when an
	  exception is reported.

#
# Miscellaneous debugging options
#

config OPENOCD_SUPPORT
	bool
	prompt "OpenOCD support [EXPERIMENTAL]"
	default n
	select THREAD_MONITOR
	help
	  This option exports an array of offsets to kernel structs, used by
	  OpenOCD to determine the state of running threads.  (This option
	  selects CONFIG_THREAD_MONITOR, so all of its caveats are implied.)

endmenu