menu "Kernel hacking"

source "lib/Kconfig.debug"

config DEBUG_STACKOVERFLOW
	bool "Check for stack overflows"
	depends on DEBUG_KERNEL
	help
	  This option will cause messages to be printed if free stack space
	  drops below a certain limit.

config DEBUG_STACK_USAGE
	bool "Stack utilization instrumentation"
	depends on DEBUG_KERNEL
	help
	  Enables the display of the minimum amount of free stack which each
	  task has ever had available in the sysrq-T and sysrq-P debug output.

	  This option will slow down process creation somewhat.

config DEBUG_PAGEALLOC
        bool "Debug page memory allocations"
        depends on DEBUG_KERNEL && !HIBERNATION
        help
          Unmap pages from the kernel linear mapping after free_pages().
          This results in a large slowdown, but helps to find certain types
          of memory corruptions.


config HCALL_STATS
	bool "Hypervisor call instrumentation"
	depends on PPC_PSERIES && DEBUG_FS
	help
	  Adds code to keep track of the number of hypervisor calls made and
	  the amount of time spent in hypervisor calls.  Wall time spent in
	  each call is always calculated, and if available CPU cycles spent
	  are also calculated.  A directory named hcall_inst is added at the
	  root of the debugfs filesystem.  Within the hcall_inst directory
	  are files that contain CPU specific call statistics.

	  This option will add a small amount of overhead to all hypervisor
	  calls.

config CODE_PATCHING_SELFTEST
	bool "Run self-tests of the code-patching code."
	depends on DEBUG_KERNEL
	default n

config FTR_FIXUP_SELFTEST
	bool "Run self-tests of the feature-fixup code."
	depends on DEBUG_KERNEL
	default n

config XMON
	bool "Include xmon kernel debugger"
	depends on DEBUG_KERNEL
	help
	  Include in-kernel hooks for the xmon kernel monitor/debugger.
	  Unless you are intending to debug the kernel, say N here.
	  Make sure to enable also CONFIG_BOOTX_TEXT on Macs. Otherwise
	  nothing will appear on the screen (xmon writes directly to the
	  framebuffer memory).
	  The cmdline option 'xmon' or 'xmon=early' will drop into xmon
	  very early during boot. 'xmon=on' will just enable the xmon
	  debugger hooks.  'xmon=off' will disable the debugger hooks
	  if CONFIG_XMON_DEFAULT is set.
	  xmon will print a backtrace on the very first invocation.
	  'xmon=nobt' will disable this autobacktrace.

config XMON_DEFAULT
	bool "Enable xmon by default"
	depends on XMON
	help
	  xmon is normally disabled unless booted with 'xmon=on'.
	  Use 'xmon=off' to disable xmon init during runtime.

config XMON_DISASSEMBLY
	bool "Include disassembly support in xmon"
	depends on XMON
	default y
	help
	  Include support for disassembling in xmon. You probably want
	  to say Y here, unless you're building for a memory-constrained
	  system.

config DEBUGGER
	bool
	depends on KGDB || XMON
	default y

config IRQSTACKS
	bool "Use separate kernel stacks when processing interrupts"
	help
	  If you say Y here the kernel will use separate kernel stacks
	  for handling hard and soft interrupts.  This can help avoid
	  overflowing the process kernel stacks.

config VIRQ_DEBUG
	bool "Expose hardware/virtual IRQ mapping via debugfs"
	depends on DEBUG_FS
	help
	  This option will show the mapping relationship between hardware irq
	  numbers and virtual irq numbers. The mapping is exposed via debugfs
	  in the file powerpc/virq_mapping.

	  If you don't know what this means you don't need it.

config BDI_SWITCH
	bool "Include BDI-2000 user context switcher"
	depends on DEBUG_KERNEL && PPC32
	help
	  Include in-kernel support for the Abatron BDI2000 debugger.
	  Unless you are intending to debug the kernel with one of these
	  machines, say N here.

config BOOTX_TEXT
	bool "Support for early boot text console (BootX or OpenFirmware only)"
	depends on PPC_OF && PPC_MULTIPLATFORM
	help
	  Say Y here to see progress messages from the boot firmware in text
	  mode. Requires either BootX or Open Firmware.

config PPC_EARLY_DEBUG
	bool "Early debugging (dangerous)"
	# PPC_EARLY_DEBUG on 440 leaves AS=1 mappings above the TLB high water
	# mark, which doesn't work with current 440 KVM.
	depends on !KVM
	help
	  Say Y to enable some early debugging facilities that may be available
	  for your processor/board combination. Those facilities are hacks
	  intended to debug problems early during boot, this should not be
	  enabled in a production kernel.
	  Note that enabling this will also cause the kernel default log level
	  to be pushed to max automatically very early during boot

choice
	prompt "Early debugging console"
	depends on PPC_EARLY_DEBUG
	help
	  Use the selected console for early debugging. Careful, if you
	  enable debugging for the wrong type of machine your kernel
	  _will not boot_.

config PPC_EARLY_DEBUG_LPAR
	bool "LPAR HV Console"
	depends on PPC_PSERIES
	help
	  Select this to enable early debugging for a machine with a HVC
	  console on vterm 0.

config PPC_EARLY_DEBUG_G5
	bool "Apple G5"
	depends on PPC_PMAC64
	help
	  Select this to enable early debugging for Apple G5 machines.

config PPC_EARLY_DEBUG_RTAS_PANEL
	bool "RTAS Panel"
	depends on PPC_RTAS
	help
	  Select this to enable early debugging via the RTAS panel.

config PPC_EARLY_DEBUG_RTAS_CONSOLE
	bool "RTAS Console"
	depends on PPC_RTAS
	select UDBG_RTAS_CONSOLE
	help
	  Select this to enable early debugging via the RTAS console.

config PPC_EARLY_DEBUG_MAPLE
	bool "Maple real mode"
	depends on PPC_MAPLE
	help
	  Select this to enable early debugging for Maple.

config PPC_EARLY_DEBUG_ISERIES
	bool "iSeries HV Console"
	depends on PPC_ISERIES
	help
	  Select this to enable early debugging for legacy iSeries. You need
	  to hit "Ctrl-x Ctrl-x" to see the messages on the console.

config PPC_EARLY_DEBUG_PAS_REALMODE
	bool "PA Semi real mode"
	depends on PPC_PASEMI
	help
	  Select this to enable early debugging for PA Semi.
	  Output will be on UART0.

config PPC_EARLY_DEBUG_BEAT
	bool "Beat HV Console"
	depends on PPC_CELLEB
	select PPC_UDBG_BEAT
	help
	  Select this to enable early debugging for Celleb with Beat.

config PPC_EARLY_DEBUG_44x
	bool "Early serial debugging for IBM/AMCC 44x CPUs"
	depends on 44x
	help
	  Select this to enable early debugging for IBM 44x chips via the
	  inbuilt serial port.  If you enable this, ensure you set
          PPC_EARLY_DEBUG_44x_PHYSLOW below to suit your target board.

config PPC_EARLY_DEBUG_40x
	bool "Early serial debugging for IBM/AMCC 40x CPUs"
	depends on 40x
	help
	  Select this to enable early debugging for IBM 40x chips via the
	  inbuilt serial port. This works on chips with a 16550 compatible
	  UART. Xilinx chips with uartlite cannot use this option.

config PPC_EARLY_DEBUG_CPM
	bool "Early serial debugging for Freescale CPM-based serial ports"
	depends on SERIAL_CPM
	select PIN_TLB if PPC_8xx
	help
	  Select this to enable early debugging for Freescale chips
	  using a CPM-based serial port.  This assumes that the bootwrapper
	  has run, and set up the CPM in a particular way.

endchoice

config PPC_EARLY_DEBUG_44x_PHYSLOW
	hex "Low 32 bits of early debug UART physical address"
	depends on PPC_EARLY_DEBUG_44x
	default "0x40000200"
	help
	  You probably want 0x40000200 for ebony boards and
          0x40000300 for taishan

config PPC_EARLY_DEBUG_44x_PHYSHIGH
	hex "EPRN of early debug UART physical address"
	depends on PPC_EARLY_DEBUG_44x
	default "0x1"

config PPC_EARLY_DEBUG_40x_PHYSADDR
	hex "Early debug UART physical address"
	depends on PPC_EARLY_DEBUG_40x
	default "0xef600300"

config PPC_EARLY_DEBUG_CPM_ADDR
	hex "CPM UART early debug transmit descriptor address"
	depends on PPC_EARLY_DEBUG_CPM
	default "0xfa202008" if PPC_EP88XC
	default "0xf0001ff8" if CPM2
	default "0xff002008" if CPM1
	help
	  This specifies the address of the transmit descriptor
	  used for early debug output.  Because it is needed before
	  platform probing is done, all platforms selected must
	  share the same address.

endmenu