LXR linux/arch/arm/Kconfig.debug

   1menu "Kernel hacking"
   2
   3source "lib/Kconfig.debug"
   4
   5config STRICT_DEVMEM
   6        bool "Filter access to /dev/mem"
   7        depends on MMU
   8        ---help---
   9          If this option is disabled, you allow userspace (root) access to all
  10          of memory, including kernel and userspace memory. Accidental
  11          access to this is obviously disastrous, but specific access can
  12          be used by people debugging the kernel.
  13
  14          If this option is switched on, the /dev/mem file only allows
  15          userspace access to memory mapped peripherals.
  16
  17          If in doubt, say Y.
  18
  19# RMK wants arm kernels compiled with frame pointers or stack unwinding.
  20# If you know what you are doing and are willing to live without stack
  21# traces, you can get a slightly smaller kernel by setting this option to
  22# n, but then RMK will have to kill you ;).
  23config FRAME_POINTER
  24        bool
  25        depends on !THUMB2_KERNEL
  26        default y if !ARM_UNWIND || FUNCTION_GRAPH_TRACER
  27        help
  28          If you say N here, the resulting kernel will be slightly smaller and
  29          faster. However, if neither FRAME_POINTER nor ARM_UNWIND are enabled,
  30          when a problem occurs with the kernel, the information that is
  31          reported is severely limited.
  32
  33config ARM_UNWIND
  34        bool "Enable stack unwinding support (EXPERIMENTAL)"
  35        depends on AEABI && EXPERIMENTAL
  36        default y
  37        help
  38          This option enables stack unwinding support in the kernel
  39          using the information automatically generated by the
  40          compiler. The resulting kernel image is slightly bigger but
  41          the performance is not affected. Currently, this feature
  42          only works with EABI compilers. If unsure say Y.
  43
  44config OLD_MCOUNT
  45        bool
  46        depends on FUNCTION_TRACER && FRAME_POINTER
  47        default y
  48
  49config DEBUG_USER
  50        bool "Verbose user fault messages"
  51        help
  52          When a user program crashes due to an exception, the kernel can
  53          print a brief message explaining what the problem was. This is
  54          sometimes helpful for debugging but serves no purpose on a
  55          production system. Most people should say N here.
  56
  57          In addition, you need to pass user_debug=N on the kernel command
  58          line to enable this feature.  N consists of the sum of:
  59
  60              1 - undefined instruction events
  61              2 - system calls
  62              4 - invalid data aborts
  63              8 - SIGSEGV faults
  64             16 - SIGBUS faults
  65
  66# These options are only for real kernel hackers who want to get their hands dirty.
  67config DEBUG_LL
  68        bool "Kernel low-level debugging functions"
  69        depends on DEBUG_KERNEL
  70        help
  71          Say Y here to include definitions of printascii, printch, printhex
  72          in the kernel.  This is helpful if you are debugging code that
  73          executes before the console is initialized.
  74
  75config EARLY_PRINTK
  76        bool "Early printk"
  77        depends on DEBUG_LL
  78        help
  79          Say Y here if you want to have an early console using the
  80          kernel low-level debugging functions. Add earlyprintk to your
  81          kernel parameters to enable this console.
  82
  83config DEBUG_ICEDCC
  84        bool "Kernel low-level debugging via EmbeddedICE DCC channel"
  85        depends on DEBUG_LL
  86        help
  87          Say Y here if you want the debug print routines to direct their
  88          output to the EmbeddedICE macrocell's DCC channel using
  89          co-processor 14. This is known to work on the ARM9 style ICE
  90          channel and on the XScale with the PEEDI.
  91
  92          It does include a timeout to ensure that the system does not
  93          totally freeze when there is nothing connected to read.
  94
  95config OC_ETM
  96        bool "On-chip ETM and ETB"
  97        select ARM_AMBA
  98        help
  99          Enables the on-chip embedded trace macrocell and embedded trace
 100          buffer driver that will allow you to collect traces of the
 101          kernel code.
 102
 103config DEBUG_DC21285_PORT
 104        bool "Kernel low-level debugging messages via footbridge serial port"
 105        depends on DEBUG_LL && FOOTBRIDGE
 106        help
 107          Say Y here if you want the debug print routines to direct their
 108          output to the serial port in the DC21285 (Footbridge). Saying N
 109          will cause the debug messages to appear on the first 16550
 110          serial port.
 111
 112config DEBUG_CLPS711X_UART2
 113        bool "Kernel low-level debugging messages via UART2"
 114        depends on DEBUG_LL && ARCH_CLPS711X
 115        help
 116          Say Y here if you want the debug print routines to direct their
 117          output to the second serial port on these devices.  Saying N will
 118          cause the debug messages to appear on the first serial port.
 119
 120config DEBUG_S3C_UART
 121        depends on PLAT_SAMSUNG
 122        int "S3C UART to use for low-level debug"
 123        default "0"
 124        help
 125          Choice for UART for kernel low-level using S3C UARTS,
 126          should be between zero and two. The port must have been
 127          initialised by the boot-loader before use.
 128
 129          The uncompressor code port configuration is now handled
 130          by CONFIG_S3C_LOWLEVEL_UART_PORT.
 131
 132endmenu
 133