Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

menu "Kernel hacking"

config TRACE_IRQFLAGS_SUPPORT
        def_bool y

source "lib/Kconfig.debug"

config EARLY_PRINTK
        bool "Early printk" if EMBEDDED && DEBUG_KERNEL && X86_32
        default y
        help
          Write kernel log output directly into the VGA buffer or to a serial
          port.

          This is useful for kernel debugging when your machine crashes very
          early before the console code is initialized. For normal operation
          it is not recommended because it looks ugly and doesn't cooperate
          with klogd/syslogd or the X server. You should normally N here,
          unless you want to debug such a crash.

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.

comment "Page alloc debug is incompatible with Software Suspend on i386"
        depends on DEBUG_KERNEL && HIBERNATION
        depends on X86_32

config DEBUG_PAGEALLOC
        bool "Debug page memory allocations"
        depends on DEBUG_KERNEL && !HIBERNATION && !HUGETLBFS
        depends on X86_32
        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 DEBUG_RODATA
        bool "Write protect kernel read-only data structures"
        depends on DEBUG_KERNEL
        help
          Mark the kernel read-only data as write-protected in the pagetables,
          in order to catch accidental (and incorrect) writes to such const
          data. This option may have a slight performance impact because a
          portion of the kernel code won't be covered by a 2MB TLB anymore.
          If in doubt, say "N".

config 4KSTACKS
        bool "Use 4Kb for kernel stacks instead of 8Kb"
        depends on DEBUG_KERNEL
        depends on X86_32
        help
          If you say Y here the kernel will use a 4Kb stacksize for the
          kernel stack attached to each process/thread. This facilitates
          running more threads on a system and also reduces the pressure
          on the VM subsystem for higher order allocations. This option
          will also use IRQ stacks to compensate for the reduced stackspace.

config X86_FIND_SMP_CONFIG
        def_bool y
        depends on X86_LOCAL_APIC || X86_VOYAGER
        depends on X86_32

config X86_MPPARSE
        def_bool y
        depends on X86_LOCAL_APIC && !X86_VISWS
        depends on X86_32

config DOUBLEFAULT
        default y
        bool "Enable doublefault exception handler" if EMBEDDED
        depends on X86_32
        help
          This option allows trapping of rare doublefault exceptions that
          would otherwise cause a system to silently reboot. Disabling this
          option saves about 4k and might cause you much additional grey
          hair.

config IOMMU_DEBUG
        bool "Enable IOMMU debugging"
        depends on GART_IOMMU && DEBUG_KERNEL
        depends on X86_64
        help
          Force the IOMMU to on even when you have less than 4GB of
          memory and add debugging code. On overflow always panic. And
          allow to enable IOMMU leak tracing. Can be disabled at boot
          time with iommu=noforce. This will also enable scatter gather
          list merging.  Currently not recommended for production
          code. When you use it make sure you have a big enough
          IOMMU/AGP aperture.  Most of the options enabled by this can
          be set more finegrained using the iommu= command line
          options. See Documentation/x86_64/boot-options.txt for more
          details.

config IOMMU_LEAK
        bool "IOMMU leak tracing"
        depends on DEBUG_KERNEL
        depends on IOMMU_DEBUG
        help
          Add a simple leak tracer to the IOMMU code. This is useful when you
          are debugging a buggy device driver that leaks IOMMU mappings.

endmenu