xref: /openbmc/linux/arch/arm/Kconfig.debug (revision b627b4ed)
1menu "Kernel hacking"
2
3source "lib/Kconfig.debug"
4
5# RMK wants arm kernels compiled with frame pointers or stack unwinding.
6# If you know what you are doing and are willing to live without stack
7# traces, you can get a slightly smaller kernel by setting this option to
8# n, but then RMK will have to kill you ;).
9config FRAME_POINTER
10	bool
11	default y if !ARM_UNWIND
12	help
13	  If you say N here, the resulting kernel will be slightly smaller and
14	  faster. However, if neither FRAME_POINTER nor ARM_UNWIND are enabled,
15	  when a problem occurs with the kernel, the information that is
16	  reported is severely limited.
17
18config ARM_UNWIND
19	bool "Enable stack unwinding support"
20	depends on AEABI && EXPERIMENTAL
21	default y
22	help
23	  This option enables stack unwinding support in the kernel
24	  using the information automatically generated by the
25	  compiler. The resulting kernel image is slightly bigger but
26	  the performance is not affected. Currently, this feature
27	  only works with EABI compilers. If unsure say Y.
28
29config DEBUG_USER
30	bool "Verbose user fault messages"
31	help
32	  When a user program crashes due to an exception, the kernel can
33	  print a brief message explaining what the problem was. This is
34	  sometimes helpful for debugging but serves no purpose on a
35	  production system. Most people should say N here.
36
37	  In addition, you need to pass user_debug=N on the kernel command
38	  line to enable this feature.  N consists of the sum of:
39
40	      1 - undefined instruction events
41	      2 - system calls
42	      4 - invalid data aborts
43	      8 - SIGSEGV faults
44	     16 - SIGBUS faults
45
46config DEBUG_ERRORS
47	bool "Verbose kernel error messages"
48	depends on DEBUG_KERNEL
49	help
50	  This option controls verbose debugging information which can be
51	  printed when the kernel detects an internal error. This debugging
52	  information is useful to kernel hackers when tracking down problems,
53	  but mostly meaningless to other people. It's safe to say Y unless
54	  you are concerned with the code size or don't want to see these
55	  messages.
56
57config DEBUG_STACK_USAGE
58	bool "Enable stack utilization instrumentation"
59	depends on DEBUG_KERNEL
60	help
61	  Enables the display of the minimum amount of free stack which each
62	  task has ever had available in the sysrq-T output.
63
64# These options are only for real kernel hackers who want to get their hands dirty.
65config DEBUG_LL
66	bool "Kernel low-level debugging functions"
67	depends on DEBUG_KERNEL
68	help
69	  Say Y here to include definitions of printascii, printch, printhex
70	  in the kernel.  This is helpful if you are debugging code that
71	  executes before the console is initialized.
72
73config DEBUG_ICEDCC
74	bool "Kernel low-level debugging via EmbeddedICE DCC channel"
75	depends on DEBUG_LL
76	help
77	  Say Y here if you want the debug print routines to direct their
78	  output to the EmbeddedICE macrocell's DCC channel using
79	  co-processor 14. This is known to work on the ARM9 style ICE
80	  channel and on the XScale with the PEEDI.
81
82	  It does include a timeout to ensure that the system does not
83	  totally freeze when there is nothing connected to read.
84
85config DEBUG_DC21285_PORT
86	bool "Kernel low-level debugging messages via footbridge serial port"
87	depends on DEBUG_LL && FOOTBRIDGE
88	help
89	  Say Y here if you want the debug print routines to direct their
90	  output to the serial port in the DC21285 (Footbridge). Saying N
91	  will cause the debug messages to appear on the first 16550
92	  serial port.
93
94config DEBUG_CLPS711X_UART2
95	bool "Kernel low-level debugging messages via UART2"
96	depends on DEBUG_LL && ARCH_CLPS711X
97	help
98	  Say Y here if you want the debug print routines to direct their
99	  output to the second serial port on these devices.  Saying N will
100	  cause the debug messages to appear on the first serial port.
101
102config DEBUG_S3C_PORT
103	depends on DEBUG_LL && PLAT_S3C
104	bool "Kernel low-level debugging messages via S3C UART"
105	help
106	  Say Y here if you want debug print routines to go to one of the
107	  S3C internal UARTs. The chosen UART must have been configured
108	  before it is used.
109
110config DEBUG_S3C_UART
111	depends on PLAT_S3C
112	int "S3C UART to use for low-level debug"
113	default "0"
114	help
115	  Choice for UART for kernel low-level using S3C UARTS,
116	  should be between zero and two. The port must have been
117	  initialised by the boot-loader before use.
118
119	  The uncompressor code port configuration is now handled
120	  by CONFIG_S3C_LOWLEVEL_UART_PORT.
121
122endmenu
123