freebsd-nq/rescue
Ryan Moeller 94cba8034b Move ifconfig SFP status functionality into libifconfig
libifconfig_sfp.h provides an API in libifconfig for querying SFP module
properties, operational status, and vendor strings, as well as descriptions
of the various fields, string conversions, and other useful helpers for
implementing user interfaces.

SFP module status is obtained by reading registers via an I2C interface.
Descriptions of these registers and the values therein have been collected
in a Lua table which is used to generate all the boilerplace C headers and
source files for accessing these values, their names, and descriptions.
The generated code is fully commented and readable.

This is the first use of libifconfig in ifconfig itself.  For now, the
scope remains very limited.  Over time, more of ifconfig will be replaced
with libifconfig.

Some minor changes to the formatting of ifconfig output have been made:
- Module memory hex dumps are indented one extra space as a result of using
hexdump(3) instead of a bespoke hex dump function.
- Media descriptions have an added two-character short-name in parenthesis.
- QSFP modules were incorrectly displaying TX bias current as power.  Now
  TX channels display bias current, and this change has been made for both
  SFP and QSFP modules for consistency.

A Lua binding for libifconfig including this functionality is implemented
but has not been included in this commit.  The plan is for it to be
committed after dynamic module loading has been enabled in flua.

Reviewed by:	kp, melifaro
Relnotes:	yes
Differential Revision:	https://reviews.freebsd.org/D25494
2020-08-09 16:27:28 +00:00
..
librescue Make rescue use SRCTOP 2017-03-12 18:59:09 +00:00
rescue Move ifconfig SFP status functionality into libifconfig 2020-08-09 16:27:28 +00:00
Makefile
README rescue: say gbye to 'boot floppies' and moderize 2017-10-29 21:21:39 +00:00

The /rescue build system here has three goals:

1) Produce a reliable standalone set of /rescue tools.

The contents of /rescue are all statically linked and do not depend on
anything in /bin or /sbin.  In particular, they'll continue to
function even if you've hosed your dynamic /bin and /sbin.  For
example, note that /rescue/mount runs /rescue/mount_nfs and not
/sbin/mount_nfs.  This is more subtle than it looks.

As an added bonus, /rescue is fairly small (thanks to crunchgen) and
includes a number of tools (such as gzip, bzip2, vi) that are not
normally found in /bin and /sbin.

2) Demonstrate robust use of crunchgen.

These Makefiles recompile each of the crunchgen components and include
support for overriding specific library entries.  Such techniques
should be useful elsewhere.

3) Produce a toolkit suitable for small distributions.

Install /rescue on a CD or CompactFlash disk, and symlink /bin and
/sbin to /rescue to produce a small and fairly complete FreeBSD
system.

These tools have one big disadvantage: being statically linked, they
cannot use some advanced library functions that rely on dynamic
linking.  In particular, nsswitch, locales, and pam all
rely on dynamic linking.


To compile:

# cd /usr/src/rescue
# make obj
# make
# make install

Note that rebuilds don't always work correctly; if you run into
trouble, try 'make clean' before recompiling.

$FreeBSD$