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 && !SOFTWARE_SUSPEND 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 callsr. 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 DEBUGGER bool "Enable debugger hooks" depends on DEBUG_KERNEL help Include in-kernel hooks for kernel debuggers. Unless you are intending to debug the kernel, say N here. config KGDB bool "Include kgdb kernel debugger" depends on DEBUGGER && (BROKEN || PPC_GEN550 || 4xx) select DEBUG_INFO help Include in-kernel hooks for kgdb, the Linux kernel source level debugger. See for more information. Unless you are intending to debug the kernel, say N here. choice prompt "Serial Port" depends on KGDB default KGDB_TTYS1 config KGDB_TTYS0 bool "ttyS0" config KGDB_TTYS1 bool "ttyS1" config KGDB_TTYS2 bool "ttyS2" config KGDB_TTYS3 bool "ttyS3" endchoice config KGDB_CONSOLE bool "Enable serial console thru kgdb port" depends on KGDB && 8xx || CPM2 help If you enable this, all serial console messages will be sent over the gdb stub. If unsure, say N. config XMON bool "Include xmon kernel debugger" depends on DEBUGGER 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 IRQSTACKS bool "Use separate kernel stacks when processing interrupts" depends on PPC64 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 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 PPC_OF 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)" 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 select PPC_UDBG_16550 help Select this to enable early debugging for IBM 44x chips via the inbuilt serial port. endchoice config PPC_EARLY_DEBUG_44x_PHYSLOW hex "Low 32 bits of early debug UART physical address" depends PPC_EARLY_DEBUG_44x default "0x40000200" config PPC_EARLY_DEBUG_44x_PHYSHIGH hex "EPRN of early debug UART physical address" depends PPC_EARLY_DEBUG_44x default "0x1" endmenu