If this option is disabled, you allow userspace (root) access to all of memory, including kernel and userspace memory. Accidental access to this is obviously disastrous, but specific access can be used by people debugging the kernel. If this option is switched on, the /dev/mem file only allows userspace access to memory mapped peripherals. If in doubt, say Y.
If you say N here, the resulting kernel will be slightly smaller and faster. However, if neither FRAME_POINTER nor ARM_UNWIND are enabled, when a problem occurs with the kernel, the information that is reported is severely limited.
This option enables stack unwinding support in the kernel using the information automatically generated by the compiler. The resulting kernel image is slightly bigger but the performance is not affected. Currently, this feature only works with EABI compilers. If unsure say Y.
When a user program crashes due to an exception, the kernel can print a brief message explaining what the problem was. This is sometimes helpful for debugging but serves no purpose on a production system. Most people should say N here. In addition, you need to pass user_debug=N on the kernel command line to enable this feature. N consists of the sum of: 1 - undefined instruction events 2 - system calls 4 - invalid data aborts 8 - SIGSEGV faults 16 - SIGBUS faults
Say Y here to include definitions of printascii, printch, printhex in the kernel. This is helpful if you are debugging code that executes before the console is initialized.
Say Y here if you want to have an early console using the kernel low-level debugging functions. Add earlyprintk to your kernel parameters to enable this console.
Say Y here if you want the debug print routines to direct their output to the EmbeddedICE macrocell's DCC channel using co-processor 14. This is known to work on the ARM9 style ICE channel and on the XScale with the PEEDI. It does include a timeout to ensure that the system does not totally freeze when there is nothing connected to read.
Enables the on-chip embedded trace macrocell and embedded trace buffer driver that will allow you to collect traces of the kernel code.
Say Y here if you want the debug print routines to direct their output to the serial port in the DC21285 (Footbridge). Saying N will cause the debug messages to appear on the first 16550 serial port.
Say Y here if you want the debug print routines to direct their output to the second serial port on these devices. Saying N will cause the debug messages to appear on the first serial port.
Choice for UART for kernel low-level using S3C UARTS, should be between zero and two. The port must have been initialised by the boot-loader before use. The uncompressor code port configuration is now handled by CONFIG_S3C_LOWLEVEL_UART_PORT.