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 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_UART 209 bool "i.MX31 Debug UART" 210 depends on SOC_IMX31 211 help 212 Say Y here if you want kernel low-level debugging support 213 on i.MX31. 214 215 config DEBUG_IMX35_UART 216 bool "i.MX35 Debug UART" 217 depends on SOC_IMX35 218 help 219 Say Y here if you want kernel low-level debugging support 220 on i.MX35. 221 222 config DEBUG_IMX51_UART 223 bool "i.MX51 Debug UART" 224 depends on SOC_IMX51 225 help 226 Say Y here if you want kernel low-level debugging support 227 on i.MX51. 228 229 config DEBUG_IMX53_UART 230 bool "i.MX53 Debug UART" 231 depends on SOC_IMX53 232 help 233 Say Y here if you want kernel low-level debugging support 234 on i.MX53. 235 236 config DEBUG_IMX6Q_UART 237 bool "i.MX6Q Debug UART" 238 depends on SOC_IMX6Q 239 help 240 Say Y here if you want kernel low-level debugging support 241 on i.MX6Q. 242 243 config DEBUG_MMP_UART2 244 bool "Kernel low-level debugging message via MMP UART2" 245 depends on ARCH_MMP 246 help 247 Say Y here if you want kernel low-level debugging support 248 on MMP UART2. 249 250 config DEBUG_MMP_UART3 251 bool "Kernel low-level debugging message via MMP UART3" 252 depends on ARCH_MMP 253 help 254 Say Y here if you want kernel low-level debugging support 255 on MMP UART3. 256 257 config DEBUG_MSM_UART1 258 bool "Kernel low-level debugging messages via MSM UART1" 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 first serial port on MSM devices. 263 264 config DEBUG_MSM_UART2 265 bool "Kernel low-level debugging messages via MSM UART2" 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 second serial port on MSM devices. 270 271 config DEBUG_MSM_UART3 272 bool "Kernel low-level debugging messages via MSM UART3" 273 depends on ARCH_MSM7X00A || ARCH_MSM7X30 || ARCH_QSD8X50 274 help 275 Say Y here if you want the debug print routines to direct 276 their output to the third serial port on MSM devices. 277 278 config DEBUG_MSM8660_UART 279 bool "Kernel low-level debugging messages via MSM 8660 UART" 280 depends on ARCH_MSM8X60 281 select MSM_HAS_DEBUG_UART_HS 282 help 283 Say Y here if you want the debug print routines to direct 284 their output to the serial port on MSM 8660 devices. 285 286 config DEBUG_MSM8960_UART 287 bool "Kernel low-level debugging messages via MSM 8960 UART" 288 depends on ARCH_MSM8960 289 select MSM_HAS_DEBUG_UART_HS 290 help 291 Say Y here if you want the debug print routines to direct 292 their output to the serial port on MSM 8960 devices. 293 294 config DEBUG_MVEBU_UART 295 bool "Kernel low-level debugging messages via MVEBU UART" 296 depends on ARCH_MVEBU 297 help 298 Say Y here if you want kernel low-level debugging support 299 on MVEBU based platforms. 300 301 config DEBUG_OMAP2PLUS_UART 302 bool "Kernel low-level debugging messages via OMAP2PLUS UART" 303 depends on ARCH_OMAP2PLUS 304 help 305 Say Y here if you want kernel low-level debugging support 306 on OMAP2PLUS based platforms. 307 308 config DEBUG_PICOXCELL_UART 309 depends on ARCH_PICOXCELL 310 bool "Use PicoXcell UART for low-level debug" 311 help 312 Say Y here if you want kernel low-level debugging support 313 on PicoXcell based platforms. 314 315 config DEBUG_REALVIEW_STD_PORT 316 bool "RealView Default UART" 317 depends on ARCH_REALVIEW 318 help 319 Say Y here if you want the debug print routines to direct 320 their output to the serial port on RealView EB, PB11MP, PBA8 321 and PBX platforms. 322 323 config DEBUG_REALVIEW_PB1176_PORT 324 bool "RealView PB1176 UART" 325 depends on MACH_REALVIEW_PB1176 326 help 327 Say Y here if you want the debug print routines to direct 328 their output to the standard serial port on the RealView 329 PB1176 platform. 330 331 config DEBUG_S3C_UART0 332 depends on PLAT_SAMSUNG 333 bool "Use S3C UART 0 for low-level debug" 334 help 335 Say Y here if you want the debug print routines to direct 336 their output to UART 0. The port must have been initialised 337 by the boot-loader before use. 338 339 The uncompressor code port configuration is now handled 340 by CONFIG_S3C_LOWLEVEL_UART_PORT. 341 342 config DEBUG_S3C_UART1 343 depends on PLAT_SAMSUNG 344 bool "Use S3C UART 1 for low-level debug" 345 help 346 Say Y here if you want the debug print routines to direct 347 their output to UART 1. The port must have been initialised 348 by the boot-loader before use. 349 350 The uncompressor code port configuration is now handled 351 by CONFIG_S3C_LOWLEVEL_UART_PORT. 352 353 config DEBUG_S3C_UART2 354 depends on PLAT_SAMSUNG 355 bool "Use S3C UART 2 for low-level debug" 356 help 357 Say Y here if you want the debug print routines to direct 358 their output to UART 2. The port must have been initialised 359 by the boot-loader before use. 360 361 The uncompressor code port configuration is now handled 362 by CONFIG_S3C_LOWLEVEL_UART_PORT. 363 364 config DEBUG_S3C_UART3 365 depends on PLAT_SAMSUNG && ARCH_EXYNOS 366 bool "Use S3C UART 3 for low-level debug" 367 help 368 Say Y here if you want the debug print routines to direct 369 their output to UART 3. The port must have been initialised 370 by the boot-loader before use. 371 372 The uncompressor code port configuration is now handled 373 by CONFIG_S3C_LOWLEVEL_UART_PORT. 374 375 config DEBUG_SOCFPGA_UART 376 depends on ARCH_SOCFPGA 377 bool "Use SOCFPGA UART for low-level debug" 378 help 379 Say Y here if you want kernel low-level debugging support 380 on SOCFPGA based platforms. 381 382 config DEBUG_SUNXI_UART0 383 bool "Kernel low-level debugging messages via sunXi UART0" 384 depends on ARCH_SUNXI 385 help 386 Say Y here if you want kernel low-level debugging support 387 on Allwinner A1X based platforms on the UART0. 388 389 config DEBUG_SUNXI_UART1 390 bool "Kernel low-level debugging messages via sunXi UART1" 391 depends on ARCH_SUNXI 392 help 393 Say Y here if you want kernel low-level debugging support 394 on Allwinner A1X based platforms on the UART1. 395 396 config DEBUG_TEGRA_UART 397 depends on ARCH_TEGRA 398 bool "Use Tegra UART for low-level debug" 399 help 400 Say Y here if you want kernel low-level debugging support 401 on Tegra based platforms. 402 403 config DEBUG_SIRFPRIMA2_UART1 404 bool "Kernel low-level debugging messages via SiRFprimaII UART1" 405 depends on ARCH_PRIMA2 406 help 407 Say Y here if you want the debug print routines to direct 408 their output to the uart1 port on SiRFprimaII devices. 409 410 config DEBUG_SIRFMARCO_UART1 411 bool "Kernel low-level debugging messages via SiRFmarco UART1" 412 depends on ARCH_MARCO 413 help 414 Say Y here if you want the debug print routines to direct 415 their output to the uart1 port on SiRFmarco devices. 416 417 config DEBUG_VEXPRESS_UART0_DETECT 418 bool "Autodetect UART0 on Versatile Express Cortex-A core tiles" 419 depends on ARCH_VEXPRESS && CPU_CP15_MMU 420 help 421 This option enables a simple heuristic which tries to determine 422 the motherboard's memory map variant (original or RS1) and then 423 choose the relevant UART0 base address. 424 425 Note that this will only work with standard A-class core tiles, 426 and may fail with non-standard SMM or custom software models. 427 428 config DEBUG_VEXPRESS_UART0_CA9 429 bool "Use PL011 UART0 at 0x10009000 (V2P-CA9 core tile)" 430 depends on ARCH_VEXPRESS 431 help 432 This option selects UART0 at 0x10009000. Except for custom models, 433 this applies only to the V2P-CA9 tile. 434 435 config DEBUG_VEXPRESS_UART0_RS1 436 bool "Use PL011 UART0 at 0x1c090000 (RS1 complaint tiles)" 437 depends on ARCH_VEXPRESS 438 help 439 This option selects UART0 at 0x1c090000. This applies to most 440 of the tiles using the RS1 memory map, including all new A-class 441 core tiles, FPGA-based SMMs and software models. 442 443 config DEBUG_VT8500_UART0 444 bool "Use UART0 on VIA/Wondermedia SoCs" 445 depends on ARCH_VT8500 446 help 447 This option selects UART0 on VIA/Wondermedia System-on-a-chip 448 devices, including VT8500, WM8505, WM8650 and WM8850. 449 450 config DEBUG_LL_UART_NONE 451 bool "No low-level debugging UART" 452 depends on !ARCH_MULTIPLATFORM 453 help 454 Say Y here if your platform doesn't provide a UART option 455 below. This relies on your platform choosing the right UART 456 definition internally in order for low-level debugging to 457 work. 458 459 config DEBUG_ICEDCC 460 bool "Kernel low-level debugging via EmbeddedICE DCC channel" 461 help 462 Say Y here if you want the debug print routines to direct 463 their output to the EmbeddedICE macrocell's DCC channel using 464 co-processor 14. This is known to work on the ARM9 style ICE 465 channel and on the XScale with the PEEDI. 466 467 Note that the system will appear to hang during boot if there 468 is nothing connected to read from the DCC. 469 470 config DEBUG_SEMIHOSTING 471 bool "Kernel low-level debug output via semihosting I/O" 472 help 473 Semihosting enables code running on an ARM target to use 474 the I/O facilities on a host debugger/emulator through a 475 simple SVC call. The host debugger or emulator must have 476 semihosting enabled for the special svc call to be trapped 477 otherwise the kernel will crash. 478 479 This is known to work with OpenOCD, as well as 480 ARM's Fast Models, or any other controlling environment 481 that implements semihosting. 482 483 For more details about semihosting, please see 484 chapter 8 of DUI0203I_rvct_developer_guide.pdf from ARM Ltd. 485 486endchoice 487 488config DEBUG_IMX_UART_PORT 489 int "i.MX Debug UART Port Selection" if DEBUG_IMX1_UART || \ 490 DEBUG_IMX25_UART || \ 491 DEBUG_IMX21_IMX27_UART || \ 492 DEBUG_IMX31_UART || \ 493 DEBUG_IMX35_UART || \ 494 DEBUG_IMX51_UART || \ 495 DEBUG_IMX53_UART || \ 496 DEBUG_IMX6Q_UART 497 default 1 498 depends on ARCH_MXC 499 help 500 Choose UART port on which kernel low-level debug messages 501 should be output. 502 503choice 504 prompt "Low-level debug console UART" 505 depends on DEBUG_OMAP2PLUS_UART 506 507 config DEBUG_OMAP2UART1 508 bool "OMAP2/3/4 UART1 (omap2/3 sdp boards and some omap3 boards)" 509 help 510 This covers at least h4, 2430sdp, 3430sdp, 3630sdp, 511 omap3 torpedo and 3530 lv som. 512 513 config DEBUG_OMAP2UART2 514 bool "OMAP2/3/4 UART2" 515 516 config DEBUG_OMAP2UART3 517 bool "OMAP2 UART3 (n8x0)" 518 519 config DEBUG_OMAP3UART3 520 bool "OMAP3 UART3 (most omap3 boards)" 521 help 522 This covers at least cm_t3x, beagle, crane, devkit8000, 523 igep00x0, ldp, n900, n9(50), pandora, overo, touchbook, 524 and 3517evm. 525 526 config DEBUG_OMAP4UART3 527 bool "OMAP4/5 UART3 (omap4 blaze, panda, omap5 sevm)" 528 529 config DEBUG_OMAP3UART4 530 bool "OMAP36XX UART4" 531 532 config DEBUG_OMAP4UART4 533 bool "OMAP4/5 UART4" 534 535 config DEBUG_TI81XXUART1 536 bool "TI81XX UART1 (ti8148evm)" 537 538 config DEBUG_TI81XXUART2 539 bool "TI81XX UART2" 540 541 config DEBUG_TI81XXUART3 542 bool "TI81XX UART3 (ti8168evm)" 543 544 config DEBUG_AM33XXUART1 545 bool "AM33XX UART1" 546 547 config DEBUG_ZOOM_UART 548 bool "Zoom2/3 UART" 549endchoice 550 551choice 552 prompt "Low-level debug console UART" 553 depends on DEBUG_LL && DEBUG_TEGRA_UART 554 555 config TEGRA_DEBUG_UART_AUTO_ODMDATA 556 bool "Via ODMDATA" 557 help 558 Automatically determines which UART to use for low-level debug based 559 on the ODMDATA value. This value is part of the BCT, and is written 560 to the boot memory device using nvflash, or other flashing tool. 561 When bits 19:18 are 3, then bits 17:15 indicate which UART to use; 562 0/1/2/3/4 are UART A/B/C/D/E. 563 564 config TEGRA_DEBUG_UARTA 565 bool "UART A" 566 567 config TEGRA_DEBUG_UARTB 568 bool "UART B" 569 570 config TEGRA_DEBUG_UARTC 571 bool "UART C" 572 573 config TEGRA_DEBUG_UARTD 574 bool "UART D" 575 576 config TEGRA_DEBUG_UARTE 577 bool "UART E" 578 579endchoice 580 581config DEBUG_LL_INCLUDE 582 string 583 default "debug/icedcc.S" if DEBUG_ICEDCC 584 default "debug/imx.S" if DEBUG_IMX1_UART || \ 585 DEBUG_IMX25_UART || \ 586 DEBUG_IMX21_IMX27_UART || \ 587 DEBUG_IMX31_UART || \ 588 DEBUG_IMX35_UART || \ 589 DEBUG_IMX51_UART || \ 590 DEBUG_IMX53_UART ||\ 591 DEBUG_IMX6Q_UART 592 default "debug/highbank.S" if DEBUG_HIGHBANK_UART 593 default "debug/mvebu.S" if DEBUG_MVEBU_UART 594 default "debug/omap2plus.S" if DEBUG_OMAP2PLUS_UART 595 default "debug/picoxcell.S" if DEBUG_PICOXCELL_UART 596 default "debug/socfpga.S" if DEBUG_SOCFPGA_UART 597 default "debug/sunxi.S" if DEBUG_SUNXI_UART0 || DEBUG_SUNXI_UART1 598 default "debug/vexpress.S" if DEBUG_VEXPRESS_UART0_DETECT || \ 599 DEBUG_VEXPRESS_UART0_CA9 || DEBUG_VEXPRESS_UART0_RS1 600 default "debug/vt8500.S" if DEBUG_VT8500_UART0 601 default "debug/tegra.S" if DEBUG_TEGRA_UART 602 default "debug/zynq.S" if DEBUG_ZYNQ_UART0 || DEBUG_ZYNQ_UART1 603 default "mach/debug-macro.S" 604 605config EARLY_PRINTK 606 bool "Early printk" 607 depends on DEBUG_LL 608 help 609 Say Y here if you want to have an early console using the 610 kernel low-level debugging functions. Add earlyprintk to your 611 kernel parameters to enable this console. 612 613config OC_ETM 614 bool "On-chip ETM and ETB" 615 depends on ARM_AMBA 616 help 617 Enables the on-chip embedded trace macrocell and embedded trace 618 buffer driver that will allow you to collect traces of the 619 kernel code. 620 621config ARM_KPROBES_TEST 622 tristate "Kprobes test module" 623 depends on KPROBES && MODULES 624 help 625 Perform tests of kprobes API and instruction set simulation. 626 627config PID_IN_CONTEXTIDR 628 bool "Write the current PID to the CONTEXTIDR register" 629 depends on CPU_COPY_V6 630 help 631 Enabling this option causes the kernel to write the current PID to 632 the PROCID field of the CONTEXTIDR register, at the expense of some 633 additional instructions during context switch. Say Y here only if you 634 are planning to use hardware trace tools with this kernel. 635 636endmenu 637