menu "Kernel hacking" source "lib/Kconfig.debug" config PRINT_STACK_DEPTH int "Stack depth to print" if DEBUG_KERNEL default 64 help This option allows you to set the stack depth that the kernel prints in stack traces. This can be useful if your display is too small and stack traces cause important information to scroll off the screen. 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 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 MSI_BITMAP_SELFTEST bool "Run self-tests of the MSI bitmap 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_BOOK3S 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