mirror of
https://github.com/apache/nuttx.git
synced 2026-10-08 06:45:19 +00:00
f6ecf80ebb
The documentation grew one page at a time, so the tree follows the
history of who wrote what and not the shape of NuttX. Scheduling is
spread over three places, a driver page can sit above the subsystem
that owns it, and the front page lists everything at the same level.
That is a lot to face when all you want to know is where the scheduler
lives.
This change files every page under the code it describes. It is a move,
not a rewrite: outside the ten pages named below, every page keeps the
text that is already in master, and no page's text is deleted.
What it does:
* Groups the table of contents into nine chapters.
* Moves the OS subsystems under os/: scheduling, memory, drivers,
filesystem, networking, IPC, interrupts, libs, time.
* Renames the platform pages to the names the source tree uses, and
derives their tags from the tree instead of by hand.
* Splits guides/ by subject.
* Adds Documentation/redirects.py, with a rule for every page that left
its old path, so old URLs keep working. The redirect page also carries
a link's #anchor across to the new page.
Ten pages have text that is new or rewritten. Nine of them are the
landing page of a chapter, which has to exist for the new structure:
index the front page
os/index OS Design
os/scheduling/index Scheduling
os/interrupts/index Interrupts
os/ipc/index IPC
os/time/index Time and timers
about/index About
developing/index Developing NuttX
ReleaseNotes/index Release notes
The tenth is os/libs/libbuiltin, the only page here with technical
content: libs/libbuiltin/ had no page at all. Five SVG diagrams come
with these pages, hand-written XML with no editor metadata.
Nothing outside Documentation/ is touched.
How it was checked:
* Sphinx builds with -W: no warnings, and no document left outside a
toctree.
* A script, offered in the PR, proves the narrow claim this rests on.
For every page outside the ten named above it erases what a move
touches -- link target, path, tag line, toctree block, table border --
from the whole old text and the whole new text, and requires the two
to be byte for byte identical. It also requires every sentence of a
deleted page to turn up somewhere, and every page that left its old
path to have a redirect, from a URL that existed, to where its content
went. It exits non-zero and names the page if any of that is not true,
and it tests added pages too, so forgetting to declare one cannot make
it pass.
* An independent audit checked 133 factual claims on these ten pages
against the tree, one shell command per claim: 130 confirmed, 1
refuted and fixed here, 2 not checkable.
* tools/checkpatch.sh is clean over the range.
The diff is large because moving a page changes every link that points
to it. Most of it is pure renames, and board pages that gained one tag
line.
Assisted-by: Claude:claude-opus-5
95 lines
No EOL
3.1 KiB
ReStructuredText
95 lines
No EOL
3.1 KiB
ReStructuredText
=======
|
|
Logging
|
|
=======
|
|
|
|
NuttX provides the SYSLOG for application and OS logging, which can be
|
|
configured in various ways to select how these messages are displayed
|
|
(see details :doc:`here </os/drivers/special/syslog>`).
|
|
|
|
Applications can emit logging messages using the standard :c:func:`syslog`
|
|
interface.
|
|
|
|
.. note:: The standard :c:func:`openlog` and :c:func:`closelog`
|
|
are not currently supported.
|
|
|
|
.. c:function:: void syslog(int priority, const char *fmt, ...)
|
|
|
|
This interface allows to send messages to SYSLOG using standard
|
|
:c:func:`printf` formatting.
|
|
|
|
Each message sent to SYSLOG is assigned a priority. Depending
|
|
on system configuration this message may or not appear in the
|
|
output.
|
|
|
|
:param priority: A priority given by ``LOG_*`` family of
|
|
definitions.
|
|
|
|
:param fmt: The format string
|
|
|
|
.. c:function:: void vsyslog(int priority, const char *fmt, va_list ap)
|
|
|
|
Performs the same task as :c:func:`syslog` with the
|
|
difference that it takes a set of arguments which have been obtained
|
|
using the :file:`include/stdarg.h` variable argument list macros.
|
|
|
|
.. c:function:: int setlogmask(int mask)
|
|
|
|
Sets the logging mask which controls which messages appear on SYSLOG
|
|
output. :c:func:`setlogmask` is not a thread-safe, re-entrant function.
|
|
Concurrent use will have undefined behavior.
|
|
|
|
:param mask: The new mask to set.
|
|
See :c:macro:`LOG_MASK` and :c:macro:`LOG_UPTO`.
|
|
Per OpenGroup.org "If the maskpri argument is 0, the current log mask
|
|
is not modified." In this implementation, the value zero is permitted
|
|
in order to disable all syslog levels.
|
|
|
|
:returns: The previous mask.
|
|
|
|
.. warning:: Per POSIX the syslog mask should be a per-process value but in
|
|
NuttX, the scope of the mask is dependent on the nature of the build:
|
|
|
|
* Flat Build: There is one, global SYSLOG mask that controls all output.
|
|
* Protected Build: There are two SYSLOG masks. One within the kernel
|
|
that controls only kernel output. And one in user-space that controls
|
|
only user SYSLOG output.
|
|
* Kernel Build: The kernel build is compliant with the POSIX requirement:
|
|
There will be one mask for each user process, controlling the SYSLOG
|
|
output only form that process. There will be a separate mask
|
|
accessible only in the kernel code to control kernel SYSLOG output.
|
|
|
|
Priority Levels
|
|
===============
|
|
|
|
The following levels are defined:
|
|
|
|
================ ===========
|
|
Priority (macro) Description
|
|
================ ===========
|
|
``LOG_EMERG`` System is unusable
|
|
``LOG_ALERT`` Action must be taken immediately
|
|
``LOG_CRIT`` Critical conditions
|
|
``LOG_ERR`` Error conditions
|
|
``LOG_WARNING`` Warning conditions
|
|
``LOG_NOTICE`` Normal, but significant, condition
|
|
``LOG_INFO`` Informational message
|
|
``LOG_DEBUG`` Debug-level message
|
|
================ ===========
|
|
|
|
Priority mask
|
|
=============
|
|
|
|
The following macros can be used with :c:func:`setlogmask`:
|
|
|
|
.. c:macro:: LOG_MASK(p)
|
|
|
|
Returns the logmask corresponding priority ``p``
|
|
|
|
.. c:macro:: LOG_UPTO(p)
|
|
|
|
Returns the logmask of all SYSLOG priorities
|
|
up to and including ``p``.
|
|
|
|
.. c:macro:: LOG_ALL
|
|
|
|
Mask corresponding to all priorities enabled |