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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_DC21285_PORT
136 bool "Kernel low-level debugging messages via footbridge serial port"
137 depends on FOOTBRIDGE
138 help
139 Say Y here if you want the debug print routines to direct
140 their output to the serial port in the DC21285 (Footbridge).
141
142 config DEBUG_FOOTBRIDGE_COM1
143 bool "Kernel low-level debugging messages via footbridge 8250 at PCI COM1"
144 depends on FOOTBRIDGE
145 help
146 Say Y here if you want the debug print routines to direct
147 their output to the 8250 at PCI COM1.
148
149 config DEBUG_HIGHBANK_UART
150 bool "Kernel low-level debugging messages via Highbank UART"
151 depends on ARCH_HIGHBANK
152 help
153 Say Y here if you want the debug print routines to direct
154 their output to the UART on Highbank based devices.
155
156 config DEBUG_IMX1_UART
157 bool "i.MX1 Debug UART"
158 depends on SOC_IMX1
159 help
160 Say Y here if you want kernel low-level debugging support
161 on i.MX1.
162
163 config DEBUG_IMX23_UART
164 bool "i.MX23 Debug UART"
165 depends on SOC_IMX23
166 help
167 Say Y here if you want kernel low-level debugging support
168 on i.MX23.
169
170 config DEBUG_IMX25_UART
171 bool "i.MX25 Debug UART"
172 depends on SOC_IMX25
173 help
174 Say Y here if you want kernel low-level debugging support
175 on i.MX25.
176
177 config DEBUG_IMX21_IMX27_UART
178 bool "i.MX21 and i.MX27 Debug UART"
179 depends on SOC_IMX21 || SOC_IMX27
180 help
181 Say Y here if you want kernel low-level debugging support
182 on i.MX21 or i.MX27.
183
184 config DEBUG_IMX28_UART
185 bool "i.MX28 Debug UART"
186 depends on SOC_IMX28
187 help
188 Say Y here if you want kernel low-level debugging support
189 on i.MX28.
190
191 config DEBUG_IMX31_IMX35_UART
192 bool "i.MX31 and i.MX35 Debug UART"
193 depends on SOC_IMX31 || SOC_IMX35
194 help
195 Say Y here if you want kernel low-level debugging support
196 on i.MX31 or i.MX35.
197
198 config DEBUG_IMX51_UART
199 bool "i.MX51 Debug UART"
200 depends on SOC_IMX51
201 help
202 Say Y here if you want kernel low-level debugging support
203 on i.MX51.
204
205 config DEBUG_IMX50_IMX53_UART
206 bool "i.MX50 and i.MX53 Debug UART"
207 depends on SOC_IMX50 || SOC_IMX53
208 help
209 Say Y here if you want kernel low-level debugging support
210 on i.MX50 or i.MX53.
211
212 config DEBUG_IMX6Q_UART2
213 bool "i.MX6Q Debug UART2"
214 depends on SOC_IMX6Q
215 help
216 Say Y here if you want kernel low-level debugging support
217 on i.MX6Q UART2. This is correct for e.g. the SabreLite
218 board.
219
220 config DEBUG_IMX6Q_UART4
221 bool "i.MX6Q Debug UART4"
222 depends on SOC_IMX6Q
223 help
224 Say Y here if you want kernel low-level debugging support
225 on i.MX6Q UART4.
226
227 config DEBUG_MSM_UART1
228 bool "Kernel low-level debugging messages via MSM UART1"
229 depends on ARCH_MSM7X00A || ARCH_MSM7X30 || ARCH_QSD8X50
230 help
231 Say Y here if you want the debug print routines to direct
232 their output to the first serial port on MSM devices.
233
234 config DEBUG_MSM_UART2
235 bool "Kernel low-level debugging messages via MSM UART2"
236 depends on ARCH_MSM7X00A || ARCH_MSM7X30 || ARCH_QSD8X50
237 help
238 Say Y here if you want the debug print routines to direct
239 their output to the second serial port on MSM devices.
240
241 config DEBUG_MSM_UART3
242 bool "Kernel low-level debugging messages via MSM UART3"
243 depends on ARCH_MSM7X00A || ARCH_MSM7X30 || ARCH_QSD8X50
244 help
245 Say Y here if you want the debug print routines to direct
246 their output to the third serial port on MSM devices.
247
248 config DEBUG_MSM8660_UART
249 bool "Kernel low-level debugging messages via MSM 8660 UART"
250 depends on ARCH_MSM8X60
251 select MSM_HAS_DEBUG_UART_HS
252 help
253 Say Y here if you want the debug print routines to direct
254 their output to the serial port on MSM 8660 devices.
255
256 config DEBUG_MSM8960_UART
257 bool "Kernel low-level debugging messages via MSM 8960 UART"
258 depends on ARCH_MSM8960
259 select MSM_HAS_DEBUG_UART_HS
260 help
261 Say Y here if you want the debug print routines to direct
262 their output to the serial port on MSM 8960 devices.
263
264 config DEBUG_REALVIEW_STD_PORT
265 bool "RealView Default UART"
266 depends on ARCH_REALVIEW
267 help
268 Say Y here if you want the debug print routines to direct
269 their output to the serial port on RealView EB, PB11MP, PBA8
270 and PBX platforms.
271
272 config DEBUG_REALVIEW_PB1176_PORT
273 bool "RealView PB1176 UART"
274 depends on MACH_REALVIEW_PB1176
275 help
276 Say Y here if you want the debug print routines to direct
277 their output to the standard serial port on the RealView
278 PB1176 platform.
279
280 config DEBUG_S3C_UART0
281 depends on PLAT_SAMSUNG
282 bool "Use S3C UART 0 for low-level debug"
283 help
284 Say Y here if you want the debug print routines to direct
285 their output to UART 0. The port must have been initialised
286 by the boot-loader before use.
287
288 The uncompressor code port configuration is now handled
289 by CONFIG_S3C_LOWLEVEL_UART_PORT.
290
291 config DEBUG_S3C_UART1
292 depends on PLAT_SAMSUNG
293 bool "Use S3C UART 1 for low-level debug"
294 help
295 Say Y here if you want the debug print routines to direct
296 their output to UART 1. The port must have been initialised
297 by the boot-loader before use.
298
299 The uncompressor code port configuration is now handled
300 by CONFIG_S3C_LOWLEVEL_UART_PORT.
301
302 config DEBUG_S3C_UART2
303 depends on PLAT_SAMSUNG
304 bool "Use S3C UART 2 for low-level debug"
305 help
306 Say Y here if you want the debug print routines to direct
307 their output to UART 2. The port must have been initialised
308 by the boot-loader before use.
309
310 The uncompressor code port configuration is now handled
311 by CONFIG_S3C_LOWLEVEL_UART_PORT.
312
313 config DEBUG_LL_UART_NONE
314 bool "No low-level debugging UART"
315 help
316 Say Y here if your platform doesn't provide a UART option
317 below. This relies on your platform choosing the right UART
318 definition internally in order for low-level debugging to
319 work.
320
321 config DEBUG_ICEDCC
322 bool "Kernel low-level debugging via EmbeddedICE DCC channel"
323 help
324 Say Y here if you want the debug print routines to direct
325 their output to the EmbeddedICE macrocell's DCC channel using
326 co-processor 14. This is known to work on the ARM9 style ICE
327 channel and on the XScale with the PEEDI.
328
329 Note that the system will appear to hang during boot if there
330 is nothing connected to read from the DCC.
331
332 config DEBUG_SEMIHOSTING
333 bool "Kernel low-level debug output via semihosting I"
334 help
335 Semihosting enables code running on an ARM target to use
336 the I/O facilities on a host debugger/emulator through a
337 simple SVC calls. The host debugger or emulator must have
338 semihosting enabled for the special svc call to be trapped
339 otherwise the kernel will crash.
340
341 This is known to work with OpenOCD, as wellas
342 ARM's Fast Models, or any other controlling environment
343 that implements semihosting.
344
345 For more details about semihosting, please see
346 chapter 8 of DUI0203I_rvct_developer_guide.pdf from ARM Ltd.
347
348endchoice
349
350config EARLY_PRINTK
351 bool "Early printk"
352 depends on DEBUG_LL
353 help
354 Say Y here if you want to have an early console using the
355 kernel low-level debugging functions. Add earlyprintk to your
356 kernel parameters to enable this console.
357
358config OC_ETM
359 bool "On-chip ETM and ETB"
360 depends on ARM_AMBA
361 help
362 Enables the on-chip embedded trace macrocell and embedded trace
363 buffer driver that will allow you to collect traces of the
364 kernel code.
365
366config ARM_KPROBES_TEST
367 tristate "Kprobes test module"
368 depends on KPROBES && MODULES
369 help
370 Perform tests of kprobes API and instruction set simulation.
371
372endmenu
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"
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
75config EARLY_PRINTK
76 bool "Early printk"
77 depends on DEBUG_LL
78 help
79 Say Y here if you want to have an early console using the
80 kernel low-level debugging functions. Add earlyprintk to your
81 kernel parameters to enable this console.
82
83config DEBUG_ICEDCC
84 bool "Kernel low-level debugging via EmbeddedICE DCC channel"
85 depends on DEBUG_LL
86 help
87 Say Y here if you want the debug print routines to direct their
88 output to the EmbeddedICE macrocell's DCC channel using
89 co-processor 14. This is known to work on the ARM9 style ICE
90 channel and on the XScale with the PEEDI.
91
92 It does include a timeout to ensure that the system does not
93 totally freeze when there is nothing connected to read.
94
95config OC_ETM
96 bool "On-chip ETM and ETB"
97 select ARM_AMBA
98 help
99 Enables the on-chip embedded trace macrocell and embedded trace
100 buffer driver that will allow you to collect traces of the
101 kernel code.
102
103config DEBUG_DC21285_PORT
104 bool "Kernel low-level debugging messages via footbridge serial port"
105 depends on DEBUG_LL && FOOTBRIDGE
106 help
107 Say Y here if you want the debug print routines to direct their
108 output to the serial port in the DC21285 (Footbridge). Saying N
109 will cause the debug messages to appear on the first 16550
110 serial port.
111
112config DEBUG_CLPS711X_UART2
113 bool "Kernel low-level debugging messages via UART2"
114 depends on DEBUG_LL && ARCH_CLPS711X
115 help
116 Say Y here if you want the debug print routines to direct their
117 output to the second serial port on these devices. Saying N will
118 cause the debug messages to appear on the first serial port.
119
120config DEBUG_S3C_UART
121 depends on PLAT_SAMSUNG
122 int "S3C UART to use for low-level debug"
123 default "0"
124 help
125 Choice for UART for kernel low-level using S3C UARTS,
126 should be between zero and two. The port must have been
127 initialised by the boot-loader before use.
128
129 The uncompressor code port configuration is now handled
130 by CONFIG_S3C_LOWLEVEL_UART_PORT.
131
132endmenu