arch/arm/Kconfig.debug - kernel/msm-4.19 - Gitiles

 menu "Kernel hacking"

 source "lib/Kconfig.debug"

 config STRICT_DEVMEM
 	bool "Filter access to /dev/mem"
 	depends on MMU
 	---help---
 	  If this option is disabled, you allow userspace (root) access to all
 	  of memory, including kernel and userspace memory. Accidental
 	  access to this is obviously disastrous, but specific access can
 	  be used by people debugging the kernel.

 	  If this option is switched on, the /dev/mem file only allows
 	  userspace access to memory mapped peripherals.

           If in doubt, say Y.

 # RMK wants arm kernels compiled with frame pointers or stack unwinding.
 # If you know what you are doing and are willing to live without stack
 # traces, you can get a slightly smaller kernel by setting this option to
 # n, but then RMK will have to kill you ;).
 config FRAME_POINTER
 	bool
 	depends on !THUMB2_KERNEL
 	default y if !ARM_UNWIND || FUNCTION_GRAPH_TRACER
 	help
 	  If you say N here, the resulting kernel will be slightly smaller and
 	  faster. However, if neither FRAME_POINTER nor ARM_UNWIND are enabled,
 	  when a problem occurs with the kernel, the information that is
 	  reported is severely limited.

 config ARM_UNWIND
 	bool "Enable stack unwinding support (EXPERIMENTAL)"
 	depends on AEABI && EXPERIMENTAL
 	default y
 	help
 	  This option enables stack unwinding support in the kernel
 	  using the information automatically generated by the
 	  compiler. The resulting kernel image is slightly bigger but
 	  the performance is not affected. Currently, this feature
 	  only works with EABI compilers. If unsure say Y.

 config OLD_MCOUNT
 	bool
 	depends on FUNCTION_TRACER && FRAME_POINTER
 	default y

 config DEBUG_USER
 	bool "Verbose user fault messages"
 	help
 	  When a user program crashes due to an exception, the kernel can
 	  print a brief message explaining what the problem was. This is
 	  sometimes helpful for debugging but serves no purpose on a
 	  production system. Most people should say N here.

 	  In addition, you need to pass user_debug=N on the kernel command
 	  line to enable this feature.  N consists of the sum of:

 	      1 - undefined instruction events
 	      2 - system calls
 	      4 - invalid data aborts
 	      8 - SIGSEGV faults
 	     16 - SIGBUS faults

 # These options are only for real kernel hackers who want to get their hands dirty.
 config DEBUG_LL
 	bool "Kernel low-level debugging functions (read help!)"
 	depends on DEBUG_KERNEL
 	help
 	  Say Y here to include definitions of printascii, printch, printhex
 	  in the kernel.  This is helpful if you are debugging code that
 	  executes before the console is initialized.

 	  Note that selecting this option will limit the kernel to a single
 	  UART definition, as specified below. Attempting to boot the kernel
 	  image on a different platform *will not work*, so this option should
 	  not be enabled for kernels that are intended to be portable.

 choice
 	prompt "Kernel low-level debugging port"
 	depends on DEBUG_LL

 	config DEBUG_LL_UART_NONE
 		bool "No low-level debugging UART"
 		help
 		  Say Y here if your platform doesn't provide a UART option
 		  below. This relies on your platform choosing the right UART
 		  definition internally in order for low-level debugging to
 		  work.

 	config DEBUG_ICEDCC
 		bool "Kernel low-level debugging via EmbeddedICE DCC channel"
 		help
 		  Say Y here if you want the debug print routines to direct
 		  their output to the EmbeddedICE macrocell's DCC channel using
 		  co-processor 14. This is known to work on the ARM9 style ICE
 		  channel and on the XScale with the PEEDI.

 		  Note that the system will appear to hang during boot if there
 		  is nothing connected to read from the DCC.

 	config DEBUG_FOOTBRIDGE_COM1
 		bool "Kernel low-level debugging messages via footbridge 8250 at PCI COM1"
 		depends on FOOTBRIDGE
 		help
 		  Say Y here if you want the debug print routines to direct
 		  their output to the 8250 at PCI COM1.

 	config DEBUG_DC21285_PORT
 		bool "Kernel low-level debugging messages via footbridge serial port"
 		depends on FOOTBRIDGE
 		help
 		  Say Y here if you want the debug print routines to direct
 		  their output to the serial port in the DC21285 (Footbridge).

 	config DEBUG_CLPS711X_UART1
 		bool "Kernel low-level debugging messages via UART1"
 		depends on ARCH_CLPS711X
 		help
 		  Say Y here if you want the debug print routines to direct
 		  their output to the first serial port on these devices.

 	config DEBUG_CLPS711X_UART2
 		bool "Kernel low-level debugging messages via UART2"
 		depends on ARCH_CLPS711X
 		help
 		  Say Y here if you want the debug print routines to direct
 		  their output to the second serial port on these devices.

 	config DEBUG_S3C_UART0
 		depends on PLAT_SAMSUNG
 		bool "Use S3C UART 0 for low-level debug"
 		help
 		  Say Y here if you want the debug print routines to direct
 		  their output to UART 0. The port must have been initialised
 		  by the boot-loader before use.

 		  The uncompressor code port configuration is now handled
 		  by CONFIG_S3C_LOWLEVEL_UART_PORT.

 	config DEBUG_S3C_UART1
 		depends on PLAT_SAMSUNG
 		bool "Use S3C UART 1 for low-level debug"
 		help
 		  Say Y here if you want the debug print routines to direct
 		  their output to UART 1. The port must have been initialised
 		  by the boot-loader before use.

 		  The uncompressor code port configuration is now handled
 		  by CONFIG_S3C_LOWLEVEL_UART_PORT.

 	config DEBUG_S3C_UART2
 		depends on PLAT_SAMSUNG
 		bool "Use S3C UART 2 for low-level debug"
 		help
 		  Say Y here if you want the debug print routines to direct
 		  their output to UART 2. The port must have been initialised
 		  by the boot-loader before use.

 		  The uncompressor code port configuration is now handled
 		  by CONFIG_S3C_LOWLEVEL_UART_PORT.

 endchoice

 config EARLY_PRINTK
 	bool "Early printk"
 	depends on DEBUG_LL
 	help
 	  Say Y here if you want to have an early console using the
 	  kernel low-level debugging functions. Add earlyprintk to your
 	  kernel parameters to enable this console.

 config OC_ETM
 	bool "On-chip ETM and ETB"
 	select ARM_AMBA
 	help
 	  Enables the on-chip embedded trace macrocell and embedded trace
 	  buffer driver that will allow you to collect traces of the
 	  kernel code.

 endmenu
	menu "Kernel hacking"

	source "lib/Kconfig.debug"

	config STRICT_DEVMEM
	bool "Filter access to /dev/mem"
	depends on MMU
	---help---
	If this option is disabled, you allow userspace (root) access to all
	of memory, including kernel and userspace memory. Accidental
	access to this is obviously disastrous, but specific access can
	be used by people debugging the kernel.

	If this option is switched on, the /dev/mem file only allows
	userspace access to memory mapped peripherals.

	If in doubt, say Y.

	# RMK wants arm kernels compiled with frame pointers or stack unwinding.
	# If you know what you are doing and are willing to live without stack
	# traces, you can get a slightly smaller kernel by setting this option to
	# n, but then RMK will have to kill you ;).
	config FRAME_POINTER
	bool
	depends on !THUMB2_KERNEL
	default y if !ARM_UNWIND \|\| FUNCTION_GRAPH_TRACER
	help
	If you say N here, the resulting kernel will be slightly smaller and
	faster. However, if neither FRAME_POINTER nor ARM_UNWIND are enabled,
	when a problem occurs with the kernel, the information that is
	reported is severely limited.

	config ARM_UNWIND
	bool "Enable stack unwinding support (EXPERIMENTAL)"
	depends on AEABI && EXPERIMENTAL
	default y
	help
	This option enables stack unwinding support in the kernel
	using the information automatically generated by the
	compiler. The resulting kernel image is slightly bigger but
	the performance is not affected. Currently, this feature
	only works with EABI compilers. If unsure say Y.

	config OLD_MCOUNT
	bool
	depends on FUNCTION_TRACER && FRAME_POINTER
	default y

	config DEBUG_USER
	bool "Verbose user fault messages"
	help
	When a user program crashes due to an exception, the kernel can
	print a brief message explaining what the problem was. This is
	sometimes helpful for debugging but serves no purpose on a
	production system. Most people should say N here.

	In addition, you need to pass user_debug=N on the kernel command
	line to enable this feature. N consists of the sum of:

	1 - undefined instruction events
	2 - system calls
	4 - invalid data aborts
	8 - SIGSEGV faults
	16 - SIGBUS faults

	# These options are only for real kernel hackers who want to get their hands dirty.
	config DEBUG_LL
	bool "Kernel low-level debugging functions (read help!)"
	depends on DEBUG_KERNEL
	help
	Say Y here to include definitions of printascii, printch, printhex
	in the kernel. This is helpful if you are debugging code that
	executes before the console is initialized.

	Note that selecting this option will limit the kernel to a single
	UART definition, as specified below. Attempting to boot the kernel
	image on a different platform will not work, so this option should
	not be enabled for kernels that are intended to be portable.

	choice
	prompt "Kernel low-level debugging port"
	depends on DEBUG_LL

	config DEBUG_LL_UART_NONE
	bool "No low-level debugging UART"
	help
	Say Y here if your platform doesn't provide a UART option
	below. This relies on your platform choosing the right UART
	definition internally in order for low-level debugging to
	work.

	config DEBUG_ICEDCC
	bool "Kernel low-level debugging via EmbeddedICE DCC channel"
	help
	Say Y here if you want the debug print routines to direct
	their output to the EmbeddedICE macrocell's DCC channel using
	co-processor 14. This is known to work on the ARM9 style ICE
	channel and on the XScale with the PEEDI.

	Note that the system will appear to hang during boot if there
	is nothing connected to read from the DCC.

	config DEBUG_FOOTBRIDGE_COM1
	bool "Kernel low-level debugging messages via footbridge 8250 at PCI COM1"
	depends on FOOTBRIDGE
	help
	Say Y here if you want the debug print routines to direct
	their output to the 8250 at PCI COM1.

	config DEBUG_DC21285_PORT
	bool "Kernel low-level debugging messages via footbridge serial port"
	depends on FOOTBRIDGE
	help
	Say Y here if you want the debug print routines to direct
	their output to the serial port in the DC21285 (Footbridge).

	config DEBUG_CLPS711X_UART1
	bool "Kernel low-level debugging messages via UART1"
	depends on ARCH_CLPS711X
	help
	Say Y here if you want the debug print routines to direct
	their output to the first serial port on these devices.

	config DEBUG_CLPS711X_UART2
	bool "Kernel low-level debugging messages via UART2"
	depends on ARCH_CLPS711X
	help
	Say Y here if you want the debug print routines to direct
	their output to the second serial port on these devices.

	config DEBUG_S3C_UART0
	depends on PLAT_SAMSUNG
	bool "Use S3C UART 0 for low-level debug"
	help
	Say Y here if you want the debug print routines to direct
	their output to UART 0. The port must have been initialised
	by the boot-loader before use.

	The uncompressor code port configuration is now handled
	by CONFIG_S3C_LOWLEVEL_UART_PORT.

	config DEBUG_S3C_UART1
	depends on PLAT_SAMSUNG
	bool "Use S3C UART 1 for low-level debug"
	help
	Say Y here if you want the debug print routines to direct
	their output to UART 1. The port must have been initialised
	by the boot-loader before use.

	The uncompressor code port configuration is now handled
	by CONFIG_S3C_LOWLEVEL_UART_PORT.

	config DEBUG_S3C_UART2
	depends on PLAT_SAMSUNG
	bool "Use S3C UART 2 for low-level debug"
	help
	Say Y here if you want the debug print routines to direct
	their output to UART 2. The port must have been initialised
	by the boot-loader before use.

	The uncompressor code port configuration is now handled
	by CONFIG_S3C_LOWLEVEL_UART_PORT.

	endchoice

	config EARLY_PRINTK
	bool "Early printk"
	depends on DEBUG_LL
	help
	Say Y here if you want to have an early console using the
	kernel low-level debugging functions. Add earlyprintk to your
	kernel parameters to enable this console.

	config OC_ETM
	bool "On-chip ETM and ETB"
	select ARM_AMBA
	help
	Enables the on-chip embedded trace macrocell and embedded trace
	buffer driver that will allow you to collect traces of the
	kernel code.

	endmenu