1menu "Kernel hacking" 2 3source "lib/Kconfig.debug" 4 5config STRICT_DEVMEM 6 bool "Filter access to /dev/mem" 7 depends on MMU 8 ---help--- 9 If this option is disabled, you allow userspace (root) access to all 10 of memory, including kernel and userspace memory. Accidental 11 access to this is obviously disastrous, but specific access can 12 be used by people debugging the kernel. 13 14 If this option is switched on, the /dev/mem file only allows 15 userspace access to memory mapped peripherals. 16 17 If in doubt, say Y. 18 19# RMK wants arm kernels compiled with frame pointers or stack unwinding. 20# If you know what you are doing and are willing to live without stack 21# traces, you can get a slightly smaller kernel by setting this option to 22# n, but then RMK will have to kill you ;). 23config FRAME_POINTER 24 bool 25 depends on !THUMB2_KERNEL 26 default y if !ARM_UNWIND || FUNCTION_GRAPH_TRACER 27 help 28 If you say N here, the resulting kernel will be slightly smaller and 29 faster. However, if neither FRAME_POINTER nor ARM_UNWIND are enabled, 30 when a problem occurs with the kernel, the information that is 31 reported is severely limited. 32 33config ARM_UNWIND 34 bool "Enable stack unwinding support (EXPERIMENTAL)" 35 depends on AEABI && EXPERIMENTAL 36 default y 37 help 38 This option enables stack unwinding support in the kernel 39 using the information automatically generated by the 40 compiler. The resulting kernel image is slightly bigger but 41 the performance is not affected. Currently, this feature 42 only works with EABI compilers. If unsure say Y. 43 44config OLD_MCOUNT 45 bool 46 depends on FUNCTION_TRACER && FRAME_POINTER 47 default y 48 49config DEBUG_USER 50 bool "Verbose user fault messages" 51 help 52 When a user program crashes due to an exception, the kernel can 53 print a brief message explaining what the problem was. This is 54 sometimes helpful for debugging but serves no purpose on a 55 production system. Most people should say N here. 56 57 In addition, you need to pass user_debug=N on the kernel command 58 line to enable this feature. N consists of the sum of: 59 60 1 - undefined instruction events 61 2 - system calls 62 4 - invalid data aborts 63 8 - SIGSEGV faults 64 16 - SIGBUS faults 65 66# These options are only for real kernel hackers who want to get their hands dirty. 67config DEBUG_LL 68 bool "Kernel low-level debugging functions (read help!)" 69 depends on DEBUG_KERNEL 70 help 71 Say Y here to include definitions of printascii, printch, printhex 72 in the kernel. This is helpful if you are debugging code that 73 executes before the console is initialized. 74 75 Note that selecting this option will limit the kernel to a single 76 UART definition, as specified below. Attempting to boot the kernel 77 image on a different platform *will not work*, so this option should 78 not be enabled for kernels that are intended to be portable. 79 80choice 81 prompt "Kernel low-level debugging port" 82 depends on DEBUG_LL 83 84 config AT91_DEBUG_LL_DBGU0 85 bool "Kernel low-level debugging on rm9200, 9260/9g20, 9261/9g10 and 9rl" 86 depends on HAVE_AT91_DBGU0 87 88 config AT91_DEBUG_LL_DBGU1 89 bool "Kernel low-level debugging on 9263 and 9g45" 90 depends on HAVE_AT91_DBGU1 91 92 config DEBUG_CLPS711X_UART1 93 bool "Kernel low-level debugging messages via UART1" 94 depends on ARCH_CLPS711X 95 help 96 Say Y here if you want the debug print routines to direct 97 their output to the first serial port on these devices. 98 99 config DEBUG_CLPS711X_UART2 100 bool "Kernel low-level debugging messages via UART2" 101 depends on ARCH_CLPS711X 102 help 103 Say Y here if you want the debug print routines to direct 104 their output to the second serial port on these devices. 105 106 config DEBUG_DC21285_PORT 107 bool "Kernel low-level debugging messages via footbridge serial port" 108 depends on FOOTBRIDGE 109 help 110 Say Y here if you want the debug print routines to direct 111 their output to the serial port in the DC21285 (Footbridge). 112 113 config DEBUG_FOOTBRIDGE_COM1 114 bool "Kernel low-level debugging messages via footbridge 8250 at PCI COM1" 115 depends on FOOTBRIDGE 116 help 117 Say Y here if you want the debug print routines to direct 118 their output to the 8250 at PCI COM1. 119 120 config DEBUG_HIGHBANK_UART 121 bool "Kernel low-level debugging messages via Highbank UART" 122 depends on ARCH_HIGHBANK 123 help 124 Say Y here if you want the debug print routines to direct 125 their output to the UART on Highbank based devices. 126 127 config DEBUG_IMX1_UART 128 bool "i.MX1 Debug UART" 129 depends on SOC_IMX1 130 help 131 Say Y here if you want kernel low-level debugging support 132 on i.MX1. 133 134 config DEBUG_IMX23_UART 135 bool "i.MX23 Debug UART" 136 depends on SOC_IMX23 137 help 138 Say Y here if you want kernel low-level debugging support 139 on i.MX23. 140 141 config DEBUG_IMX25_UART 142 bool "i.MX25 Debug UART" 143 depends on SOC_IMX25 144 help 145 Say Y here if you want kernel low-level debugging support 146 on i.MX25. 147 148 config DEBUG_IMX21_IMX27_UART 149 bool "i.MX21 and i.MX27 Debug UART" 150 depends on SOC_IMX21 || SOC_IMX27 151 help 152 Say Y here if you want kernel low-level debugging support 153 on i.MX21 or i.MX27. 154 155 config DEBUG_IMX28_UART 156 bool "i.MX28 Debug UART" 157 depends on SOC_IMX28 158 help 159 Say Y here if you want kernel low-level debugging support 160 on i.MX28. 161 162 config DEBUG_IMX31_IMX35_UART 163 bool "i.MX31 and i.MX35 Debug UART" 164 depends on SOC_IMX31 || SOC_IMX35 165 help 166 Say Y here if you want kernel low-level debugging support 167 on i.MX31 or i.MX35. 168 169 config DEBUG_IMX51_UART 170 bool "i.MX51 Debug UART" 171 depends on SOC_IMX51 172 help 173 Say Y here if you want kernel low-level debugging support 174 on i.MX51. 175 176 config DEBUG_IMX50_IMX53_UART 177 bool "i.MX50 and i.MX53 Debug UART" 178 depends on SOC_IMX50 || SOC_IMX53 179 help 180 Say Y here if you want kernel low-level debugging support 181 on i.MX50 or i.MX53. 182 183 config DEBUG_IMX6Q_UART4 184 bool "i.MX6Q Debug UART4" 185 depends on SOC_IMX6Q 186 help 187 Say Y here if you want kernel low-level debugging support 188 on i.MX6Q UART4. 189 190 config DEBUG_MSM_UART1 191 bool "Kernel low-level debugging messages via MSM UART1" 192 depends on ARCH_MSM7X00A || ARCH_MSM7X30 || ARCH_QSD8X50 193 help 194 Say Y here if you want the debug print routines to direct 195 their output to the first serial port on MSM devices. 196 197 config DEBUG_MSM_UART2 198 bool "Kernel low-level debugging messages via MSM UART2" 199 depends on ARCH_MSM7X00A || ARCH_MSM7X30 || ARCH_QSD8X50 200 help 201 Say Y here if you want the debug print routines to direct 202 their output to the second serial port on MSM devices. 203 204 config DEBUG_MSM_UART3 205 bool "Kernel low-level debugging messages via MSM UART3" 206 depends on ARCH_MSM7X00A || ARCH_MSM7X30 || ARCH_QSD8X50 207 help 208 Say Y here if you want the debug print routines to direct 209 their output to the third serial port on MSM devices. 210 211 config DEBUG_MSM8660_UART 212 bool "Kernel low-level debugging messages via MSM 8660 UART" 213 depends on ARCH_MSM8X60 214 select MSM_HAS_DEBUG_UART_HS 215 help 216 Say Y here if you want the debug print routines to direct 217 their output to the serial port on MSM 8660 devices. 218 219 config DEBUG_MSM8960_UART 220 bool "Kernel low-level debugging messages via MSM 8960 UART" 221 depends on ARCH_MSM8960 222 select MSM_HAS_DEBUG_UART_HS 223 help 224 Say Y here if you want the debug print routines to direct 225 their output to the serial port on MSM 8960 devices. 226 227 config DEBUG_REALVIEW_STD_PORT 228 bool "RealView Default UART" 229 depends on ARCH_REALVIEW 230 help 231 Say Y here if you want the debug print routines to direct 232 their output to the serial port on RealView EB, PB11MP, PBA8 233 and PBX platforms. 234 235 config DEBUG_REALVIEW_PB1176_PORT 236 bool "RealView PB1176 UART" 237 depends on MACH_REALVIEW_PB1176 238 help 239 Say Y here if you want the debug print routines to direct 240 their output to the standard serial port on the RealView 241 PB1176 platform. 242 243 config DEBUG_S3C_UART0 244 depends on PLAT_SAMSUNG 245 bool "Use S3C UART 0 for low-level debug" 246 help 247 Say Y here if you want the debug print routines to direct 248 their output to UART 0. The port must have been initialised 249 by the boot-loader before use. 250 251 The uncompressor code port configuration is now handled 252 by CONFIG_S3C_LOWLEVEL_UART_PORT. 253 254 config DEBUG_S3C_UART1 255 depends on PLAT_SAMSUNG 256 bool "Use S3C UART 1 for low-level debug" 257 help 258 Say Y here if you want the debug print routines to direct 259 their output to UART 1. The port must have been initialised 260 by the boot-loader before use. 261 262 The uncompressor code port configuration is now handled 263 by CONFIG_S3C_LOWLEVEL_UART_PORT. 264 265 config DEBUG_S3C_UART2 266 depends on PLAT_SAMSUNG 267 bool "Use S3C UART 2 for low-level debug" 268 help 269 Say Y here if you want the debug print routines to direct 270 their output to UART 2. The port must have been initialised 271 by the boot-loader before use. 272 273 The uncompressor code port configuration is now handled 274 by CONFIG_S3C_LOWLEVEL_UART_PORT. 275 276 config DEBUG_LL_UART_NONE 277 bool "No low-level debugging UART" 278 help 279 Say Y here if your platform doesn't provide a UART option 280 below. This relies on your platform choosing the right UART 281 definition internally in order for low-level debugging to 282 work. 283 284 config DEBUG_ICEDCC 285 bool "Kernel low-level debugging via EmbeddedICE DCC channel" 286 help 287 Say Y here if you want the debug print routines to direct 288 their output to the EmbeddedICE macrocell's DCC channel using 289 co-processor 14. This is known to work on the ARM9 style ICE 290 channel and on the XScale with the PEEDI. 291 292 Note that the system will appear to hang during boot if there 293 is nothing connected to read from the DCC. 294 295 config DEBUG_SEMIHOSTING 296 bool "Kernel low-level debug output via semihosting I" 297 help 298 Semihosting enables code running on an ARM target to use 299 the I/O facilities on a host debugger/emulator through a 300 simple SVC calls. The host debugger or emulator must have 301 semihosting enabled for the special svc call to be trapped 302 otherwise the kernel will crash. 303 304 This is known to work with OpenOCD, as wellas 305 ARM's Fast Models, or any other controlling environment 306 that implements semihosting. 307 308 For more details about semihosting, please see 309 chapter 8 of DUI0203I_rvct_developer_guide.pdf from ARM Ltd. 310 311endchoice 312 313config EARLY_PRINTK 314 bool "Early printk" 315 depends on DEBUG_LL 316 help 317 Say Y here if you want to have an early console using the 318 kernel low-level debugging functions. Add earlyprintk to your 319 kernel parameters to enable this console. 320 321config OC_ETM 322 bool "On-chip ETM and ETB" 323 depends on ARM_AMBA 324 help 325 Enables the on-chip embedded trace macrocell and embedded trace 326 buffer driver that will allow you to collect traces of the 327 kernel code. 328 329config ARM_KPROBES_TEST 330 tristate "Kprobes test module" 331 depends on KPROBES && MODULES 332 help 333 Perform tests of kprobes API and instruction set simulation. 334 335endmenu 336