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_DAVINCI_DA8XX_UART1 107 bool "Kernel low-level debugging on DaVinci DA8XX using UART1" 108 depends on ARCH_DAVINCI_DA8XX 109 help 110 Say Y here if you want the debug print routines to direct 111 their output to UART1 serial port on DaVinci DA8XX devices. 112 113 config DEBUG_DAVINCI_DA8XX_UART2 114 bool "Kernel low-level debugging on DaVinci DA8XX using UART2" 115 depends on ARCH_DAVINCI_DA8XX 116 help 117 Say Y here if you want the debug print routines to direct 118 their output to UART2 serial port on DaVinci DA8XX devices. 119 120 config DEBUG_DAVINCI_DMx_UART0 121 bool "Kernel low-level debugging on DaVinci DMx using UART0" 122 depends on ARCH_DAVINCI_DMx 123 help 124 Say Y here if you want the debug print routines to direct 125 their output to UART0 serial port on DaVinci DMx devices. 126 127 config DEBUG_DAVINCI_TNETV107X_UART1 128 bool "Kernel low-level debugging on DaVinci TNETV107x using UART1" 129 depends on ARCH_DAVINCI_TNETV107X 130 help 131 Say Y here if you want the debug print routines to direct 132 their output to UART1 serial port on DaVinci TNETV107X 133 devices. 134 135 config DEBUG_ZYNQ_UART0 136 bool "Kernel low-level debugging on Xilinx Zynq using UART0" 137 depends on ARCH_ZYNQ 138 help 139 Say Y here if you want the debug print routines to direct 140 their output to UART0 on the Zynq platform. 141 142 config DEBUG_ZYNQ_UART1 143 bool "Kernel low-level debugging on Xilinx Zynq using UART1" 144 depends on ARCH_ZYNQ 145 help 146 Say Y here if you want the debug print routines to direct 147 their output to UART1 on the Zynq platform. 148 149 If you have a ZC702 board and want early boot messages to 150 appear on the USB serial adaptor, select this option. 151 152 config DEBUG_DC21285_PORT 153 bool "Kernel low-level debugging messages via footbridge serial port" 154 depends on FOOTBRIDGE 155 help 156 Say Y here if you want the debug print routines to direct 157 their output to the serial port in the DC21285 (Footbridge). 158 159 config DEBUG_FOOTBRIDGE_COM1 160 bool "Kernel low-level debugging messages via footbridge 8250 at PCI COM1" 161 depends on FOOTBRIDGE 162 help 163 Say Y here if you want the debug print routines to direct 164 their output to the 8250 at PCI COM1. 165 166 config DEBUG_HIGHBANK_UART 167 bool "Kernel low-level debugging messages via Highbank UART" 168 depends on ARCH_HIGHBANK 169 help 170 Say Y here if you want the debug print routines to direct 171 their output to the UART on Highbank based devices. 172 173 config DEBUG_IMX1_UART 174 bool "i.MX1 Debug UART" 175 depends on SOC_IMX1 176 help 177 Say Y here if you want kernel low-level debugging support 178 on i.MX1. 179 180 config DEBUG_IMX23_UART 181 bool "i.MX23 Debug UART" 182 depends on SOC_IMX23 183 help 184 Say Y here if you want kernel low-level debugging support 185 on i.MX23. 186 187 config DEBUG_IMX25_UART 188 bool "i.MX25 Debug UART" 189 depends on SOC_IMX25 190 help 191 Say Y here if you want kernel low-level debugging support 192 on i.MX25. 193 194 config DEBUG_IMX21_IMX27_UART 195 bool "i.MX21 and i.MX27 Debug UART" 196 depends on SOC_IMX21 || SOC_IMX27 197 help 198 Say Y here if you want kernel low-level debugging support 199 on i.MX21 or i.MX27. 200 201 config DEBUG_IMX28_UART 202 bool "i.MX28 Debug UART" 203 depends on SOC_IMX28 204 help 205 Say Y here if you want kernel low-level debugging support 206 on i.MX28. 207 208 config DEBUG_IMX31_IMX35_UART 209 bool "i.MX31 and i.MX35 Debug UART" 210 depends on SOC_IMX31 || SOC_IMX35 211 help 212 Say Y here if you want kernel low-level debugging support 213 on i.MX31 or i.MX35. 214 215 config DEBUG_IMX51_UART 216 bool "i.MX51 Debug UART" 217 depends on SOC_IMX51 218 help 219 Say Y here if you want kernel low-level debugging support 220 on i.MX51. 221 222 config DEBUG_IMX50_IMX53_UART 223 bool "i.MX50 and i.MX53 Debug UART" 224 depends on SOC_IMX50 || SOC_IMX53 225 help 226 Say Y here if you want kernel low-level debugging support 227 on i.MX50 or i.MX53. 228 229 config DEBUG_IMX6Q_UART 230 bool "i.MX6Q Debug UART" 231 depends on SOC_IMX6Q 232 help 233 Say Y here if you want kernel low-level debugging support 234 on i.MX6Q. 235 236 config DEBUG_MMP_UART2 237 bool "Kernel low-level debugging message via MMP UART2" 238 depends on ARCH_MMP 239 help 240 Say Y here if you want kernel low-level debugging support 241 on MMP UART2. 242 243 config DEBUG_MMP_UART3 244 bool "Kernel low-level debugging message via MMP UART3" 245 depends on ARCH_MMP 246 help 247 Say Y here if you want kernel low-level debugging support 248 on MMP UART3. 249 250 config DEBUG_MSM_UART1 251 bool "Kernel low-level debugging messages via MSM UART1" 252 depends on ARCH_MSM7X00A || ARCH_MSM7X30 || ARCH_QSD8X50 253 help 254 Say Y here if you want the debug print routines to direct 255 their output to the first serial port on MSM devices. 256 257 config DEBUG_MSM_UART2 258 bool "Kernel low-level debugging messages via MSM UART2" 259 depends on ARCH_MSM7X00A || ARCH_MSM7X30 || ARCH_QSD8X50 260 help 261 Say Y here if you want the debug print routines to direct 262 their output to the second serial port on MSM devices. 263 264 config DEBUG_MSM_UART3 265 bool "Kernel low-level debugging messages via MSM UART3" 266 depends on ARCH_MSM7X00A || ARCH_MSM7X30 || ARCH_QSD8X50 267 help 268 Say Y here if you want the debug print routines to direct 269 their output to the third serial port on MSM devices. 270 271 config DEBUG_MSM8660_UART 272 bool "Kernel low-level debugging messages via MSM 8660 UART" 273 depends on ARCH_MSM8X60 274 select MSM_HAS_DEBUG_UART_HS 275 help 276 Say Y here if you want the debug print routines to direct 277 their output to the serial port on MSM 8660 devices. 278 279 config DEBUG_MSM8960_UART 280 bool "Kernel low-level debugging messages via MSM 8960 UART" 281 depends on ARCH_MSM8960 282 select MSM_HAS_DEBUG_UART_HS 283 help 284 Say Y here if you want the debug print routines to direct 285 their output to the serial port on MSM 8960 devices. 286 287 config DEBUG_MVEBU_UART 288 bool "Kernel low-level debugging messages via MVEBU UART" 289 depends on ARCH_MVEBU 290 help 291 Say Y here if you want kernel low-level debugging support 292 on MVEBU based platforms. 293 294 config DEBUG_PICOXCELL_UART 295 depends on ARCH_PICOXCELL 296 bool "Use PicoXcell UART for low-level debug" 297 help 298 Say Y here if you want kernel low-level debugging support 299 on PicoXcell based platforms. 300 301 config DEBUG_REALVIEW_STD_PORT 302 bool "RealView Default UART" 303 depends on ARCH_REALVIEW 304 help 305 Say Y here if you want the debug print routines to direct 306 their output to the serial port on RealView EB, PB11MP, PBA8 307 and PBX platforms. 308 309 config DEBUG_REALVIEW_PB1176_PORT 310 bool "RealView PB1176 UART" 311 depends on MACH_REALVIEW_PB1176 312 help 313 Say Y here if you want the debug print routines to direct 314 their output to the standard serial port on the RealView 315 PB1176 platform. 316 317 config DEBUG_S3C_UART0 318 depends on PLAT_SAMSUNG 319 bool "Use S3C UART 0 for low-level debug" 320 help 321 Say Y here if you want the debug print routines to direct 322 their output to UART 0. The port must have been initialised 323 by the boot-loader before use. 324 325 The uncompressor code port configuration is now handled 326 by CONFIG_S3C_LOWLEVEL_UART_PORT. 327 328 config DEBUG_S3C_UART1 329 depends on PLAT_SAMSUNG 330 bool "Use S3C UART 1 for low-level debug" 331 help 332 Say Y here if you want the debug print routines to direct 333 their output to UART 1. The port must have been initialised 334 by the boot-loader before use. 335 336 The uncompressor code port configuration is now handled 337 by CONFIG_S3C_LOWLEVEL_UART_PORT. 338 339 config DEBUG_S3C_UART2 340 depends on PLAT_SAMSUNG 341 bool "Use S3C UART 2 for low-level debug" 342 help 343 Say Y here if you want the debug print routines to direct 344 their output to UART 2. The port must have been initialised 345 by the boot-loader before use. 346 347 The uncompressor code port configuration is now handled 348 by CONFIG_S3C_LOWLEVEL_UART_PORT. 349 350 config DEBUG_S3C_UART3 351 depends on PLAT_SAMSUNG && ARCH_EXYNOS 352 bool "Use S3C UART 3 for low-level debug" 353 help 354 Say Y here if you want the debug print routines to direct 355 their output to UART 3. The port must have been initialised 356 by the boot-loader before use. 357 358 The uncompressor code port configuration is now handled 359 by CONFIG_S3C_LOWLEVEL_UART_PORT. 360 361 config DEBUG_SOCFPGA_UART 362 depends on ARCH_SOCFPGA 363 bool "Use SOCFPGA UART for low-level debug" 364 help 365 Say Y here if you want kernel low-level debugging support 366 on SOCFPGA based platforms. 367 368 config DEBUG_SUNXI_UART0 369 bool "Kernel low-level debugging messages via sunXi UART0" 370 depends on ARCH_SUNXI 371 help 372 Say Y here if you want kernel low-level debugging support 373 on Allwinner A1X based platforms on the UART0. 374 375 config DEBUG_SUNXI_UART1 376 bool "Kernel low-level debugging messages via sunXi UART1" 377 depends on ARCH_SUNXI 378 help 379 Say Y here if you want kernel low-level debugging support 380 on Allwinner A1X based platforms on the UART1. 381 382 config DEBUG_TEGRA_UART 383 depends on ARCH_TEGRA 384 bool "Use Tegra UART for low-level debug" 385 help 386 Say Y here if you want kernel low-level debugging support 387 on Tegra based platforms. 388 389 config DEBUG_VEXPRESS_UART0_DETECT 390 bool "Autodetect UART0 on Versatile Express Cortex-A core tiles" 391 depends on ARCH_VEXPRESS && CPU_CP15_MMU 392 help 393 This option enables a simple heuristic which tries to determine 394 the motherboard's memory map variant (original or RS1) and then 395 choose the relevant UART0 base address. 396 397 Note that this will only work with standard A-class core tiles, 398 and may fail with non-standard SMM or custom software models. 399 400 config DEBUG_VEXPRESS_UART0_CA9 401 bool "Use PL011 UART0 at 0x10009000 (V2P-CA9 core tile)" 402 depends on ARCH_VEXPRESS 403 help 404 This option selects UART0 at 0x10009000. Except for custom models, 405 this applies only to the V2P-CA9 tile. 406 407 config DEBUG_VEXPRESS_UART0_RS1 408 bool "Use PL011 UART0 at 0x1c090000 (RS1 complaint tiles)" 409 depends on ARCH_VEXPRESS 410 help 411 This option selects UART0 at 0x1c090000. This applies to most 412 of the tiles using the RS1 memory map, including all new A-class 413 core tiles, FPGA-based SMMs and software models. 414 415 config DEBUG_LL_UART_NONE 416 bool "No low-level debugging UART" 417 depends on !ARCH_MULTIPLATFORM 418 help 419 Say Y here if your platform doesn't provide a UART option 420 below. This relies on your platform choosing the right UART 421 definition internally in order for low-level debugging to 422 work. 423 424 config DEBUG_ICEDCC 425 bool "Kernel low-level debugging via EmbeddedICE DCC channel" 426 help 427 Say Y here if you want the debug print routines to direct 428 their output to the EmbeddedICE macrocell's DCC channel using 429 co-processor 14. This is known to work on the ARM9 style ICE 430 channel and on the XScale with the PEEDI. 431 432 Note that the system will appear to hang during boot if there 433 is nothing connected to read from the DCC. 434 435 config DEBUG_SEMIHOSTING 436 bool "Kernel low-level debug output via semihosting I/O" 437 help 438 Semihosting enables code running on an ARM target to use 439 the I/O facilities on a host debugger/emulator through a 440 simple SVC call. The host debugger or emulator must have 441 semihosting enabled for the special svc call to be trapped 442 otherwise the kernel will crash. 443 444 This is known to work with OpenOCD, as well as 445 ARM's Fast Models, or any other controlling environment 446 that implements semihosting. 447 448 For more details about semihosting, please see 449 chapter 8 of DUI0203I_rvct_developer_guide.pdf from ARM Ltd. 450 451endchoice 452 453config DEBUG_IMX6Q_UART_PORT 454 int "i.MX6Q Debug UART Port (1-5)" if DEBUG_IMX6Q_UART 455 range 1 5 456 default 1 457 depends on SOC_IMX6Q 458 help 459 Choose UART port on which kernel low-level debug messages 460 should be output. 461 462choice 463 prompt "Low-level debug console UART" 464 depends on DEBUG_LL && DEBUG_TEGRA_UART 465 466 config TEGRA_DEBUG_UART_AUTO_ODMDATA 467 bool "Via ODMDATA" 468 help 469 Automatically determines which UART to use for low-level debug based 470 on the ODMDATA value. This value is part of the BCT, and is written 471 to the boot memory device using nvflash, or other flashing tool. 472 When bits 19:18 are 3, then bits 17:15 indicate which UART to use; 473 0/1/2/3/4 are UART A/B/C/D/E. 474 475 config TEGRA_DEBUG_UARTA 476 bool "UART A" 477 478 config TEGRA_DEBUG_UARTB 479 bool "UART B" 480 481 config TEGRA_DEBUG_UARTC 482 bool "UART C" 483 484 config TEGRA_DEBUG_UARTD 485 bool "UART D" 486 487 config TEGRA_DEBUG_UARTE 488 bool "UART E" 489 490endchoice 491 492config DEBUG_LL_INCLUDE 493 string 494 default "debug/icedcc.S" if DEBUG_ICEDCC 495 default "debug/imx.S" if DEBUG_IMX1_UART || \ 496 DEBUG_IMX25_UART || \ 497 DEBUG_IMX21_IMX27_UART || \ 498 DEBUG_IMX31_IMX35_UART || \ 499 DEBUG_IMX51_UART || \ 500 DEBUG_IMX50_IMX53_UART ||\ 501 DEBUG_IMX6Q_UART 502 default "debug/highbank.S" if DEBUG_HIGHBANK_UART 503 default "debug/mvebu.S" if DEBUG_MVEBU_UART 504 default "debug/picoxcell.S" if DEBUG_PICOXCELL_UART 505 default "debug/socfpga.S" if DEBUG_SOCFPGA_UART 506 default "debug/sunxi.S" if DEBUG_SUNXI_UART0 || DEBUG_SUNXI_UART1 507 default "debug/vexpress.S" if DEBUG_VEXPRESS_UART0_DETECT || \ 508 DEBUG_VEXPRESS_UART0_CA9 || DEBUG_VEXPRESS_UART0_RS1 509 default "debug/tegra.S" if DEBUG_TEGRA_UART 510 default "debug/zynq.S" if DEBUG_ZYNQ_UART0 || DEBUG_ZYNQ_UART1 511 default "mach/debug-macro.S" 512 513config EARLY_PRINTK 514 bool "Early printk" 515 depends on DEBUG_LL 516 help 517 Say Y here if you want to have an early console using the 518 kernel low-level debugging functions. Add earlyprintk to your 519 kernel parameters to enable this console. 520 521config OC_ETM 522 bool "On-chip ETM and ETB" 523 depends on ARM_AMBA 524 help 525 Enables the on-chip embedded trace macrocell and embedded trace 526 buffer driver that will allow you to collect traces of the 527 kernel code. 528 529config ARM_KPROBES_TEST 530 tristate "Kprobes test module" 531 depends on KPROBES && MODULES 532 help 533 Perform tests of kprobes API and instruction set simulation. 534 535config PID_IN_CONTEXTIDR 536 bool "Write the current PID to the CONTEXTIDR register" 537 depends on CPU_COPY_V6 538 help 539 Enabling this option causes the kernel to write the current PID to 540 the PROCID field of the CONTEXTIDR register, at the expense of some 541 additional instructions during context switch. Say Y here only if you 542 are planning to use hardware trace tools with this kernel. 543 544endmenu 545