d72541f945
Debug areas can currently only be used after s390dbf initialization
which occurs as a postcore_initcall. This is too late for tracing
earlier code such as that related to console_init().
This patch introduces a macro for defining a statically initialized
debug area that can be used to trace very early code. The macro is made
available for built-in code only because modules are never running
during early boot.
Example usage:
1. Define static debug area:
DEFINE_STATIC_DEBUG_INFO(my_debug, "my_debug", 4, 1, 16,
&debug_hex_ascii_view);
2. Add trace entry:
debug_event(&my_debug, 0, "DATA", 4);
Note: The debug area is automatically registered in debugfs during boot.
A driver must not call any of the debug_register()/_unregister()
functions on a static debug_info_t!
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.