| | 1 | # SPDX-License-Identifier: GPL-2.0 |
| | 2 | |
| | 3 | config EARLY_PRINTK_USB |
| | 4 | bool |
| | 5 | |
| | 6 | config X86_VERBOSE_BOOTUP |
| | 7 | bool "Enable verbose x86 bootup info messages" |
| | 8 | default y |
| | 9 | help |
| | 10 | Enables the informational output from the decompression stage |
| | 11 | (e.g. bzImage) of the boot. If you disable this you will still |
| | 12 | see errors. Disable this if you want silent bootup. |
| | 13 | |
| | 14 | config EARLY_PRINTK |
| | 15 | bool "Early printk" if EXPERT |
| | 16 | default y |
| | 17 | help |
| | 18 | Write kernel log output directly into the VGA buffer or to a serial |
| | 19 | port. |
| | 20 | |
| | 21 | This is useful for kernel debugging when your machine crashes very |
| | 22 | early before the console code is initialized. For normal operation |
| | 23 | it is not recommended because it looks ugly and doesn't cooperate |
| | 24 | with klogd/syslogd or the X server. You should normally say N here, |
| | 25 | unless you want to debug such a crash. |
| | 26 | |
| | 27 | config EARLY_PRINTK_DBGP |
| | 28 | bool "Early printk via EHCI debug port" |
| | 29 | depends on EARLY_PRINTK && PCI |
| | 30 | select EARLY_PRINTK_USB |
| | 31 | help |
| | 32 | Write kernel log output directly into the EHCI debug port. |
| | 33 | |
| | 34 | This is useful for kernel debugging when your machine crashes very |
| | 35 | early before the console code is initialized. For normal operation |
| | 36 | it is not recommended because it looks ugly and doesn't cooperate |
| | 37 | with klogd/syslogd or the X server. You should normally say N here, |
| | 38 | unless you want to debug such a crash. You need usb debug device. |
| | 39 | |
| | 40 | config EARLY_PRINTK_USB_XDBC |
| | 41 | bool "Early printk via the xHCI debug port" |
| | 42 | depends on EARLY_PRINTK && PCI |
| | 43 | select EARLY_PRINTK_USB |
| | 44 | help |
| | 45 | Write kernel log output directly into the xHCI debug port. |
| | 46 | |
| | 47 | One use for this feature is kernel debugging, for example when your |
| | 48 | machine crashes very early before the regular console code is |
| | 49 | initialized. Other uses include simpler, lockless logging instead of |
| | 50 | a full-blown printk console driver + klogd. |
| | 51 | |
| | 52 | For normal production environments this is normally not recommended, |
| | 53 | because it doesn't feed events into klogd/syslogd and doesn't try to |
| | 54 | print anything on the screen. |
| | 55 | |
| | 56 | You should normally say N here, unless you want to debug early |
| | 57 | crashes or need a very simple printk logging facility. |
| | 58 | |
| | 59 | config EFI_PGT_DUMP |
| | 60 | bool "Dump the EFI pagetable" |
| | 61 | depends on EFI |
| | 62 | select PTDUMP |
| | 63 | help |
| | 64 | Enable this if you want to dump the EFI page table before |
| | 65 | enabling virtual mode. This can be used to debug miscellaneous |
| | 66 | issues with the mapping of the EFI runtime regions into that |
| | 67 | table. |
| | 68 | |
| | 69 | config DEBUG_TLBFLUSH |
| | 70 | bool "Set upper limit of TLB entries to flush one-by-one" |
| | 71 | depends on DEBUG_KERNEL |
| | 72 | help |
| | 73 | X86-only for now. |
| | 74 | |
| | 75 | This option allows the user to tune the amount of TLB entries the |
| | 76 | kernel flushes one-by-one instead of doing a full TLB flush. In |
| | 77 | certain situations, the former is cheaper. This is controlled by the |
| | 78 | tlb_flushall_shift knob under /sys/kernel/debug/x86. If you set it |
| | 79 | to -1, the code flushes the whole TLB unconditionally. Otherwise, |
| | 80 | for positive values of it, the kernel will use single TLB entry |
| | 81 | invalidating instructions according to the following formula: |
| | 82 | |
| | 83 | flush_entries <= active_tlb_entries / 2^tlb_flushall_shift |
| | 84 | |
| | 85 | If in doubt, say "N". |
| | 86 | |
| | 87 | config IOMMU_DEBUG |
| | 88 | bool "Enable IOMMU debugging" |
| | 89 | depends on GART_IOMMU && DEBUG_KERNEL |
| | 90 | depends on X86_64 |
| | 91 | help |
| | 92 | Force the IOMMU to on even when you have less than 4GB of |
| | 93 | memory and add debugging code. On overflow always panic. And |
| | 94 | allow to enable IOMMU leak tracing. Can be disabled at boot |
| | 95 | time with iommu=noforce. This will also enable scatter gather |
| | 96 | list merging. Currently not recommended for production |
| | 97 | code. When you use it make sure you have a big enough |
| | 98 | IOMMU/AGP aperture. Most of the options enabled by this can |
| | 99 | be set more finegrained using the iommu= command line |
| | 100 | options. See Documentation/admin-guide/kernel-parameters.txt for more |
| | 101 | details. |
| | 102 | |
| | 103 | config IOMMU_LEAK |
| | 104 | bool "IOMMU leak tracing" |
| | 105 | depends on IOMMU_DEBUG && DMA_API_DEBUG |
| | 106 | help |
| | 107 | Add a simple leak tracer to the IOMMU code. This is useful when you |
| | 108 | are debugging a buggy device driver that leaks IOMMU mappings. |
| | 109 | |
| | 110 | config HAVE_MMIOTRACE_SUPPORT |
| | 111 | def_bool y |
| | 112 | |
| | 113 | config X86_DECODER_SELFTEST |
| | 114 | bool "x86 instruction decoder selftest" |
| | 115 | depends on DEBUG_KERNEL && INSTRUCTION_DECODER |
| | 116 | depends on !COMPILE_TEST |
| | 117 | help |
| | 118 | Perform x86 instruction decoder selftests at build time. |
| | 119 | This option is useful for checking the sanity of x86 instruction |
| | 120 | decoder code. |
| | 121 | If unsure, say "N". |
| | 122 | |
| | 123 | choice |
| | 124 | prompt "IO delay type" |
| | 125 | default IO_DELAY_0X80 |
| | 126 | |
| | 127 | config IO_DELAY_0X80 |
| | 128 | bool "port 0x80 based port-IO delay [recommended]" |
| | 129 | help |
| | 130 | This is the traditional Linux IO delay used for in/out_p. |
| | 131 | It is the most tested hence safest selection here. |
| | 132 | |
| | 133 | config IO_DELAY_0XED |
| | 134 | bool "port 0xed based port-IO delay" |
| | 135 | help |
| | 136 | Use port 0xed as the IO delay. This frees up port 0x80 which is |
| | 137 | often used as a hardware-debug port. |
| | 138 | |
| | 139 | config IO_DELAY_UDELAY |
| | 140 | bool "udelay based port-IO delay" |
| | 141 | help |
| | 142 | Use udelay(2) as the IO delay method. This provides the delay |
| | 143 | while not having any side-effect on the IO port space. |
| | 144 | |
| | 145 | config IO_DELAY_NONE |
| | 146 | bool "no port-IO delay" |
| | 147 | help |
| | 148 | No port-IO delay. Will break on old boxes that require port-IO |
| | 149 | delay for certain operations. Should work on most new machines. |
| | 150 | |
| | 151 | endchoice |
| | 152 | |
| | 153 | config DEBUG_BOOT_PARAMS |
| | 154 | bool "Debug boot parameters" |
| | 155 | depends on DEBUG_KERNEL |
| | 156 | depends on DEBUG_FS |
| | 157 | help |
| | 158 | This option will cause struct boot_params to be exported via debugfs. |
| | 159 | |
| | 160 | config CPA_DEBUG |
| | 161 | bool "CPA self-test code" |
| | 162 | depends on DEBUG_KERNEL |
| | 163 | help |
| | 164 | Do change_page_attr() self-tests every 30 seconds. |
| | 165 | |
| | 166 | config DEBUG_ENTRY |
| | 167 | bool "Debug low-level entry code" |
| | 168 | depends on DEBUG_KERNEL |
| | 169 | help |
| | 170 | This option enables sanity checks in x86's low-level entry code. |
| | 171 | Some of these sanity checks may slow down kernel entries and |
| | 172 | exits or otherwise impact performance. |
| | 173 | |
| | 174 | If unsure, say N. |
| | 175 | |
| | 176 | config DEBUG_NMI_SELFTEST |
| | 177 | bool "NMI Selftest" |
| | 178 | depends on DEBUG_KERNEL && X86_LOCAL_APIC |
| | 179 | help |
| | 180 | Enabling this option turns on a quick NMI selftest to verify |
| | 181 | that the NMI behaves correctly. |
| | 182 | |
| | 183 | This might help diagnose strange hangs that rely on NMI to |
| | 184 | function properly. |
| | 185 | |
| | 186 | If unsure, say N. |
| | 187 | |
| | 188 | config DEBUG_IMR_SELFTEST |
| | 189 | bool "Isolated Memory Region self test" |
| | 190 | depends on INTEL_IMR |
| | 191 | help |
| | 192 | This option enables automated sanity testing of the IMR code. |
| | 193 | Some simple tests are run to verify IMR bounds checking, alignment |
| | 194 | and overlapping. This option is really only useful if you are |
| | 195 | debugging an IMR memory map or are modifying the IMR code and want to |
| | 196 | test your changes. |
| | 197 | |
| | 198 | If unsure say N here. |
| | 199 | |
| | 200 | config X86_DEBUG_FPU |
| | 201 | bool "Debug the x86 FPU code" |
| | 202 | depends on DEBUG_KERNEL |
| | 203 | default y |
| | 204 | help |
| | 205 | If this option is enabled then there will be extra sanity |
| | 206 | checks and (boot time) debug printouts added to the kernel. |
| | 207 | This debugging adds some small amount of runtime overhead |
| | 208 | to the kernel. |
| | 209 | |
| | 210 | If unsure, say N. |
| | 211 | |
| | 212 | config PUNIT_ATOM_DEBUG |
| | 213 | tristate "ATOM Punit debug driver" |
| | 214 | depends on PCI |
| | 215 | select DEBUG_FS |
| | 216 | select IOSF_MBI |
| | 217 | help |
| | 218 | This is a debug driver, which gets the power states |
| | 219 | of all Punit North Complex devices. The power states of |
| | 220 | each device is exposed as part of the debugfs interface. |
| | 221 | The current power state can be read from |
| | 222 | /sys/kernel/debug/punit_atom/dev_power_state |
| | 223 | |
| | 224 | choice |
| | 225 | prompt "Choose kernel unwinder" |
| | 226 | default UNWINDER_ORC if X86_64 |
| | 227 | default UNWINDER_FRAME_POINTER if X86_32 |
| | 228 | help |
| | 229 | This determines which method will be used for unwinding kernel stack |
| | 230 | traces for panics, oopses, bugs, warnings, perf, /proc/<pid>/stack, |
| | 231 | livepatch, lockdep, and more. |
| | 232 | |
| | 233 | config UNWINDER_ORC |
| | 234 | bool "ORC unwinder" |
| | 235 | depends on X86_64 |
| | 236 | select OBJTOOL |
| | 237 | help |
| | 238 | This option enables the ORC (Oops Rewind Capability) unwinder for |
| | 239 | unwinding kernel stack traces. It uses a custom data format which is |
| | 240 | a simplified version of the DWARF Call Frame Information standard. |
| | 241 | |
| | 242 | This unwinder is more accurate across interrupt entry frames than the |
| | 243 | frame pointer unwinder. It also enables a 5-10% performance |
| | 244 | improvement across the entire kernel compared to frame pointers. |
| | 245 | |
| | 246 | Enabling this option will increase the kernel's runtime memory usage |
| | 247 | by roughly 2-4MB, depending on your kernel config. |
| | 248 | |
| | 249 | config UNWINDER_FRAME_POINTER |
| | 250 | bool "Frame pointer unwinder" |
| | 251 | select ARCH_WANT_FRAME_POINTERS |
| | 252 | select FRAME_POINTER |
| | 253 | help |
| | 254 | This option enables the frame pointer unwinder for unwinding kernel |
| | 255 | stack traces. |
| | 256 | |
| | 257 | The unwinder itself is fast and it uses less RAM than the ORC |
| | 258 | unwinder, but the kernel text size will grow by ~3% and the kernel's |
| | 259 | overall performance will degrade by roughly 5-10%. |
| | 260 | |
| | 261 | config UNWINDER_GUESS |
| | 262 | bool "Guess unwinder" |
| | 263 | depends on EXPERT |
| | 264 | depends on !STACKDEPOT |
| | 265 | help |
| | 266 | This option enables the "guess" unwinder for unwinding kernel stack |
| | 267 | traces. It scans the stack and reports every kernel text address it |
| | 268 | finds. Some of the addresses it reports may be incorrect. |
| | 269 | |
| | 270 | While this option often produces false positives, it can still be |
| | 271 | useful in many cases. Unlike the other unwinders, it has no runtime |
| | 272 | overhead. |
| | 273 | |
| | 274 | endchoice |
projects / linux-2.6-block.git / blame_incremental