xref: /openbmc/linux/arch/arm/Kconfig.debug (revision 4bdf0bb7)
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	depends on !THUMB2_KERNEL
12	default y if !ARM_UNWIND
13	help
14	  If you say N here, the resulting kernel will be slightly smaller and
15	  faster. However, if neither FRAME_POINTER nor ARM_UNWIND are enabled,
16	  when a problem occurs with the kernel, the information that is
17	  reported is severely limited.
18
19config ARM_UNWIND
20	bool "Enable stack unwinding support"
21	depends on AEABI && EXPERIMENTAL
22	default y
23	help
24	  This option enables stack unwinding support in the kernel
25	  using the information automatically generated by the
26	  compiler. The resulting kernel image is slightly bigger but
27	  the performance is not affected. Currently, this feature
28	  only works with EABI compilers. If unsure say Y.
29
30config DEBUG_USER
31	bool "Verbose user fault messages"
32	help
33	  When a user program crashes due to an exception, the kernel can
34	  print a brief message explaining what the problem was. This is
35	  sometimes helpful for debugging but serves no purpose on a
36	  production system. Most people should say N here.
37
38	  In addition, you need to pass user_debug=N on the kernel command
39	  line to enable this feature.  N consists of the sum of:
40
41	      1 - undefined instruction events
42	      2 - system calls
43	      4 - invalid data aborts
44	      8 - SIGSEGV faults
45	     16 - SIGBUS faults
46
47config DEBUG_ERRORS
48	bool "Verbose kernel error messages"
49	depends on DEBUG_KERNEL
50	help
51	  This option controls verbose debugging information which can be
52	  printed when the kernel detects an internal error. This debugging
53	  information is useful to kernel hackers when tracking down problems,
54	  but mostly meaningless to other people. It's safe to say Y unless
55	  you are concerned with the code size or don't want to see these
56	  messages.
57
58config DEBUG_STACK_USAGE
59	bool "Enable stack utilization instrumentation"
60	depends on DEBUG_KERNEL
61	help
62	  Enables the display of the minimum amount of free stack which each
63	  task has ever had available in the sysrq-T output.
64
65# These options are only for real kernel hackers who want to get their hands dirty.
66config DEBUG_LL
67	bool "Kernel low-level debugging functions"
68	depends on DEBUG_KERNEL
69	help
70	  Say Y here to include definitions of printascii, printch, printhex
71	  in the kernel.  This is helpful if you are debugging code that
72	  executes before the console is initialized.
73
74config DEBUG_ICEDCC
75	bool "Kernel low-level debugging via EmbeddedICE DCC channel"
76	depends on DEBUG_LL
77	help
78	  Say Y here if you want the debug print routines to direct their
79	  output to the EmbeddedICE macrocell's DCC channel using
80	  co-processor 14. This is known to work on the ARM9 style ICE
81	  channel and on the XScale with the PEEDI.
82
83	  It does include a timeout to ensure that the system does not
84	  totally freeze when there is nothing connected to read.
85
86config DEBUG_DC21285_PORT
87	bool "Kernel low-level debugging messages via footbridge serial port"
88	depends on DEBUG_LL && FOOTBRIDGE
89	help
90	  Say Y here if you want the debug print routines to direct their
91	  output to the serial port in the DC21285 (Footbridge). Saying N
92	  will cause the debug messages to appear on the first 16550
93	  serial port.
94
95config DEBUG_CLPS711X_UART2
96	bool "Kernel low-level debugging messages via UART2"
97	depends on DEBUG_LL && ARCH_CLPS711X
98	help
99	  Say Y here if you want the debug print routines to direct their
100	  output to the second serial port on these devices.  Saying N will
101	  cause the debug messages to appear on the first serial port.
102
103config DEBUG_S3C_UART
104	depends on PLAT_S3C
105	int "S3C UART to use for low-level debug"
106	default "0"
107	help
108	  Choice for UART for kernel low-level using S3C UARTS,
109	  should be between zero and two. The port must have been
110	  initialised by the boot-loader before use.
111
112	  The uncompressor code port configuration is now handled
113	  by CONFIG_S3C_LOWLEVEL_UART_PORT.
114
115endmenu
116