Openembedded Core Discussions
 help / color / mirror / Atom feed
From: "Robert P. J. Day" <rpjday@crashcourse.ca>
To: OE Core mailing list <openembedded-core@lists.openembedded.org>
Subject: what is the value of 'BBPATH ?= ""' in layer.conf?
Date: Sun, 22 Nov 2015 04:10:51 -0500 (EST)	[thread overview]
Message-ID: <alpine.LFD.2.20.1511220407380.13727@localhost> (raw)


  perusing some wind river layers, and in the layer.conf file here:

https://github.com/WindRiver-OpenSourceLabs/wr-kernel/blob/LB21_7.0_RCPL0002/conf/layer.conf

i see the opening snippet:

  BBPATH ?= ""
  # We have a conf and classes directory, add to BBPATH
  BBPATH := "${LAYERDIR}:${BBPATH}"

what is the purpose of that initial assignment

  BBPATH ?= ""

if that variable has no value, won't it just expand to the empty
string so that the eventual effect is the same? or is there something
more subtle happening here?

rday

-- 

========================================================================
Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
LinkedIn:                               http://ca.linkedin.com/in/rpjday
========================================================================



             reply	other threads:[~2015-11-22  9:10 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-22  9:10 Robert P. J. Day [this message]
2015-11-22  9:17 ` what is the value of 'BBPATH ?= ""' in layer.conf? Robert Yang
2015-11-22  9:29   ` Robert P. J. Day
2015-11-22  9:38     ` Robert Yang
2015-11-23 14:16 ` Mark Hatle

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=alpine.LFD.2.20.1511220407380.13727@localhost \
    --to=rpjday@crashcourse.ca \
    --cc=openembedded-core@lists.openembedded.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox