1menu "Kernel hacking" 2 3source "lib/Kconfig.debug" 4 5config PRINT_STACK_DEPTH 6 int "Stack depth to print" if DEBUG_KERNEL 7 default 64 8 help 9 This option allows you to set the stack depth that the kernel 10 prints in stack traces. This can be useful if your display is 11 too small and stack traces cause important information to 12 scroll off the screen. 13 14config DEBUG_STACKOVERFLOW 15 bool "Check for stack overflows" 16 depends on DEBUG_KERNEL 17 help 18 This option will cause messages to be printed if free stack space 19 drops below a certain limit. 20 21config DEBUG_STACK_USAGE 22 bool "Stack utilization instrumentation" 23 depends on DEBUG_KERNEL 24 help 25 Enables the display of the minimum amount of free stack which each 26 task has ever had available in the sysrq-T and sysrq-P debug output. 27 28 This option will slow down process creation somewhat. 29 30config DEBUG_PAGEALLOC 31 bool "Debug page memory allocations" 32 depends on DEBUG_KERNEL && !HIBERNATION 33 depends on ARCH_SUPPORTS_DEBUG_PAGEALLOC 34 help 35 Unmap pages from the kernel linear mapping after free_pages(). 36 This results in a large slowdown, but helps to find certain types 37 of memory corruptions. 38 39 40config HCALL_STATS 41 bool "Hypervisor call instrumentation" 42 depends on PPC_PSERIES && DEBUG_FS 43 help 44 Adds code to keep track of the number of hypervisor calls made and 45 the amount of time spent in hypervisor calls. Wall time spent in 46 each call is always calculated, and if available CPU cycles spent 47 are also calculated. A directory named hcall_inst is added at the 48 root of the debugfs filesystem. Within the hcall_inst directory 49 are files that contain CPU specific call statistics. 50 51 This option will add a small amount of overhead to all hypervisor 52 calls. 53 54config CODE_PATCHING_SELFTEST 55 bool "Run self-tests of the code-patching code." 56 depends on DEBUG_KERNEL 57 default n 58 59config FTR_FIXUP_SELFTEST 60 bool "Run self-tests of the feature-fixup code." 61 depends on DEBUG_KERNEL 62 default n 63 64config MSI_BITMAP_SELFTEST 65 bool "Run self-tests of the MSI bitmap code." 66 depends on DEBUG_KERNEL 67 default n 68 69config XMON 70 bool "Include xmon kernel debugger" 71 depends on DEBUG_KERNEL 72 help 73 Include in-kernel hooks for the xmon kernel monitor/debugger. 74 Unless you are intending to debug the kernel, say N here. 75 Make sure to enable also CONFIG_BOOTX_TEXT on Macs. Otherwise 76 nothing will appear on the screen (xmon writes directly to the 77 framebuffer memory). 78 The cmdline option 'xmon' or 'xmon=early' will drop into xmon 79 very early during boot. 'xmon=on' will just enable the xmon 80 debugger hooks. 'xmon=off' will disable the debugger hooks 81 if CONFIG_XMON_DEFAULT is set. 82 xmon will print a backtrace on the very first invocation. 83 'xmon=nobt' will disable this autobacktrace. 84 85config XMON_DEFAULT 86 bool "Enable xmon by default" 87 depends on XMON 88 help 89 xmon is normally disabled unless booted with 'xmon=on'. 90 Use 'xmon=off' to disable xmon init during runtime. 91 92config XMON_DISASSEMBLY 93 bool "Include disassembly support in xmon" 94 depends on XMON 95 default y 96 help 97 Include support for disassembling in xmon. You probably want 98 to say Y here, unless you're building for a memory-constrained 99 system. 100 101config DEBUGGER 102 bool 103 depends on KGDB || XMON 104 default y 105 106config IRQSTACKS 107 bool "Use separate kernel stacks when processing interrupts" 108 help 109 If you say Y here the kernel will use separate kernel stacks 110 for handling hard and soft interrupts. This can help avoid 111 overflowing the process kernel stacks. 112 113config VIRQ_DEBUG 114 bool "Expose hardware/virtual IRQ mapping via debugfs" 115 depends on DEBUG_FS 116 help 117 This option will show the mapping relationship between hardware irq 118 numbers and virtual irq numbers. The mapping is exposed via debugfs 119 in the file powerpc/virq_mapping. 120 121 If you don't know what this means you don't need it. 122 123config BDI_SWITCH 124 bool "Include BDI-2000 user context switcher" 125 depends on DEBUG_KERNEL && PPC32 126 help 127 Include in-kernel support for the Abatron BDI2000 debugger. 128 Unless you are intending to debug the kernel with one of these 129 machines, say N here. 130 131config BOOTX_TEXT 132 bool "Support for early boot text console (BootX or OpenFirmware only)" 133 depends on PPC_OF && PPC_BOOK3S 134 help 135 Say Y here to see progress messages from the boot firmware in text 136 mode. Requires either BootX or Open Firmware. 137 138config PPC_EARLY_DEBUG 139 bool "Early debugging (dangerous)" 140 # PPC_EARLY_DEBUG on 440 leaves AS=1 mappings above the TLB high water 141 # mark, which doesn't work with current 440 KVM. 142 depends on !KVM 143 help 144 Say Y to enable some early debugging facilities that may be available 145 for your processor/board combination. Those facilities are hacks 146 intended to debug problems early during boot, this should not be 147 enabled in a production kernel. 148 Note that enabling this will also cause the kernel default log level 149 to be pushed to max automatically very early during boot 150 151choice 152 prompt "Early debugging console" 153 depends on PPC_EARLY_DEBUG 154 help 155 Use the selected console for early debugging. Careful, if you 156 enable debugging for the wrong type of machine your kernel 157 _will not boot_. 158 159config PPC_EARLY_DEBUG_LPAR 160 bool "LPAR HV Console" 161 depends on PPC_PSERIES 162 help 163 Select this to enable early debugging for a machine with a HVC 164 console on vterm 0. 165 166config PPC_EARLY_DEBUG_G5 167 bool "Apple G5" 168 depends on PPC_PMAC64 169 help 170 Select this to enable early debugging for Apple G5 machines. 171 172config PPC_EARLY_DEBUG_RTAS_PANEL 173 bool "RTAS Panel" 174 depends on PPC_RTAS 175 help 176 Select this to enable early debugging via the RTAS panel. 177 178config PPC_EARLY_DEBUG_RTAS_CONSOLE 179 bool "RTAS Console" 180 depends on PPC_RTAS 181 select UDBG_RTAS_CONSOLE 182 help 183 Select this to enable early debugging via the RTAS console. 184 185config PPC_EARLY_DEBUG_MAPLE 186 bool "Maple real mode" 187 depends on PPC_MAPLE 188 help 189 Select this to enable early debugging for Maple. 190 191config PPC_EARLY_DEBUG_ISERIES 192 bool "iSeries HV Console" 193 depends on PPC_ISERIES 194 help 195 Select this to enable early debugging for legacy iSeries. You need 196 to hit "Ctrl-x Ctrl-x" to see the messages on the console. 197 198config PPC_EARLY_DEBUG_PAS_REALMODE 199 bool "PA Semi real mode" 200 depends on PPC_PASEMI 201 help 202 Select this to enable early debugging for PA Semi. 203 Output will be on UART0. 204 205config PPC_EARLY_DEBUG_BEAT 206 bool "Beat HV Console" 207 depends on PPC_CELLEB 208 select PPC_UDBG_BEAT 209 help 210 Select this to enable early debugging for Celleb with Beat. 211 212config PPC_EARLY_DEBUG_44x 213 bool "Early serial debugging for IBM/AMCC 44x CPUs" 214 depends on 44x 215 help 216 Select this to enable early debugging for IBM 44x chips via the 217 inbuilt serial port. If you enable this, ensure you set 218 PPC_EARLY_DEBUG_44x_PHYSLOW below to suit your target board. 219 220config PPC_EARLY_DEBUG_40x 221 bool "Early serial debugging for IBM/AMCC 40x CPUs" 222 depends on 40x 223 help 224 Select this to enable early debugging for IBM 40x chips via the 225 inbuilt serial port. This works on chips with a 16550 compatible 226 UART. Xilinx chips with uartlite cannot use this option. 227 228config PPC_EARLY_DEBUG_CPM 229 bool "Early serial debugging for Freescale CPM-based serial ports" 230 depends on SERIAL_CPM 231 select PIN_TLB if PPC_8xx 232 help 233 Select this to enable early debugging for Freescale chips 234 using a CPM-based serial port. This assumes that the bootwrapper 235 has run, and set up the CPM in a particular way. 236 237endchoice 238 239config PPC_EARLY_DEBUG_44x_PHYSLOW 240 hex "Low 32 bits of early debug UART physical address" 241 depends on PPC_EARLY_DEBUG_44x 242 default "0x40000200" 243 help 244 You probably want 0x40000200 for ebony boards and 245 0x40000300 for taishan 246 247config PPC_EARLY_DEBUG_44x_PHYSHIGH 248 hex "EPRN of early debug UART physical address" 249 depends on PPC_EARLY_DEBUG_44x 250 default "0x1" 251 252config PPC_EARLY_DEBUG_40x_PHYSADDR 253 hex "Early debug UART physical address" 254 depends on PPC_EARLY_DEBUG_40x 255 default "0xef600300" 256 257config PPC_EARLY_DEBUG_CPM_ADDR 258 hex "CPM UART early debug transmit descriptor address" 259 depends on PPC_EARLY_DEBUG_CPM 260 default "0xfa202008" if PPC_EP88XC 261 default "0xf0001ff8" if CPM2 262 default "0xff002008" if CPM1 263 help 264 This specifies the address of the transmit descriptor 265 used for early debug output. Because it is needed before 266 platform probing is done, all platforms selected must 267 share the same address. 268 269endmenu 270