why conditional assignment of DEPLOY_DIR_IMAGE in bitbake.conf?
quite possibly another silly question, but i'm perusing poky's
version of bitbake.conf and i see this:
DEPLOY_DIR ?= "${TMPDIR}/deploy" DEPLOY_DIR_TAR = "${DEPLOY_DIR}/tar" DEPLOY_DIR_IPK = "${DEPLOY_DIR}/ipk" DEPLOY_DIR_RPM = "${DEPLOY_DIR}/rpm" DEPLOY_DIR_DEB = "${DEPLOY_DIR}/deb" DEPLOY_DIR_IMAGE ?= "${DEPLOY_DIR}/images/${MACHINE}" DEPLOY_DIR_TOOLS = "${DEPLOY_DIR}/tools"
now, what is the value of using "?=" to set DEPLOY_DIR_IMAGE, rather
than just "=". i know what "?=" represents, but i normally expect to see it in a context where someone might have set it earlier to some other value, but this is in bitbake.conf, before any of the "include" or "require" directives to pull in any of the other .conf files. so in the midst of all those other DEPLOY_DIR_* hard assignments, why is the images directory a conditional install?
rday
Signature · 7 lines
========================================================================
Robert P. J. Day Ottawa, Ontario, CANADA
http://crashcourse.ca
Twitter: http://twitter.com/rpjday
LinkedIn: http://ca.linkedin.com/in/rpjday
========================================================================Quoted 11 lines · Robert P. J. Day
quite possibly another silly question, but i'm perusing poky's
version of bitbake.conf and i see this:
DEPLOY_DIR?= "${TMPDIR}/deploy"DEPLOY_DIR_TAR= "${DEPLOY_DIR}/tar"DEPLOY_DIR_IPK= "${DEPLOY_DIR}/ipk"DEPLOY_DIR_RPM= "${DEPLOY_DIR}/rpm"DEPLOY_DIR_DEB= "${DEPLOY_DIR}/deb"DEPLOY_DIR_IMAGE?= "${DEPLOY_DIR}/images/${MACHINE}"DEPLOY_DIR_TOOLS= "${DEPLOY_DIR}/tools"
Quoted 8 lines
now, what is the value of using "?=" to set
DEPLOY_DIR_IMAGE, rather
than just "=". i know what "?=" represents, but i normally expect to see it in a context where someone might have set it earlier to some other value, but this is in bitbake.conf, before any of the "include" or "require" directives to pull in any of the other .conf files. so in the midst of all those other DEPLOY_DIR_* hard assignments, why is the images directory a conditional install?
s/install/define/
If there's a ?= done before any includes in bitbake.conf, either its position in the file has changed, or it's set that way to allow the user to add those variables to the env whitelist and set them in the environment, as the env is set before bitbake.conf is parsed.
Signature · 5 lines
Christopher Larson clarson at kergoth dot com Founder - BitBake, OpenEmbedded, OpenZaurus Maintainer - Tslib Senior Software Engineer, Mentor Graphics
Quoted 22 lines · Christopher Larson
On Tue, Jul 22, 2014 at 9:36 AM, Robert P. J. Day <[email protected]> wrote:
quite possibly another silly question, but i'm perusing poky's version of bitbake.conf and i see this:
DEPLOY_DIR?= "${TMPDIR}/deploy"DEPLOY_DIR_TAR= "${DEPLOY_DIR}/tar"DEPLOY_DIR_IPK= "${DEPLOY_DIR}/ipk"DEPLOY_DIR_RPM= "${DEPLOY_DIR}/rpm"DEPLOY_DIR_DEB= "${DEPLOY_DIR}/deb"DEPLOY_DIR_IMAGE?= "${DEPLOY_DIR}/images/${MACHINE}"DEPLOY_DIR_TOOLS= "${DEPLOY_DIR}/tools"now, what is the value of using "?=" to set
DEPLOY_DIR_IMAGE, rather than just "=". i know what "?=" represents, but i normally expect to see it in a context where someone might have set it earlier to some other value, but this is in bitbake.conf, before any of the "include" or "require" directives to pull in any of the other .conf files. so in the midst of all those other DEPLOY_DIR_* hard assignments, why is the images directory a conditional install?
Quoted 1 line
s/install/define/
um, quite so. :-P
Quoted 4 lines
If there's a ?= done before any includes in bitbake.conf, either its position in the file has changed, or it's set that way to allow the user to add those variables to the env whitelist and set them in the environment, as the env is set before bitbake.conf is parsed.
ah, gotcha. so the obvious question is, who decides which variables
merit this sort of behaviour and which don't? why two variables out of the DEPLOY_DIR_* variables and not the rest? seems sort of arbitrary.
rday
Signature · 7 lines
========================================================================
Robert P. J. Day Ottawa, Ontario, CANADA
http://crashcourse.ca
Twitter: http://twitter.com/rpjday
LinkedIn: http://ca.linkedin.com/in/rpjday
========================================================================Quoted 28 lines · Robert P. J. Day
Quoted 22 lines · Christopher Larson
On Tue, Jul 22, 2014 at 9:36 AM, Robert P. J. Day <[email protected]> wrote:
quite possibly another silly question, but i'm perusing poky's
version of bitbake.conf and i see this:
DEPLOY_DIR?= "${TMPDIR}/deploy"DEPLOY_DIR_TAR= "${DEPLOY_DIR}/tar"DEPLOY_DIR_IPK= "${DEPLOY_DIR}/ipk"DEPLOY_DIR_RPM= "${DEPLOY_DIR}/rpm"DEPLOY_DIR_DEB= "${DEPLOY_DIR}/deb"DEPLOY_DIR_IMAGE?= "${DEPLOY_DIR}/images/${MACHINE}"DEPLOY_DIR_TOOLS= "${DEPLOY_DIR}/tools"now, what is the value of using "?=" to set
DEPLOY_DIR_IMAGE, rather
than just "=". i know what "?=" represents, but i normally expect to see it in a context where someone might have set it earlier to some other value, but this is in bitbake.conf, before any of the "include" or "require" directives to pull in any of the other .conf files. so in the midst of all those other DEPLOY_DIR_* hard assignments, why is the images directory a conditional install?Quoted 1 line
s/install/define/
um, quite so. :-P
Quoted 8 lines
Quoted 4 lines
If there's a ?= done before any includes in bitbake.conf, either its position in the file has changed, or it's set that way to allow the user to add those variables to the env whitelist and set them in the environment, as the env is set before bitbake.conf is parsed.
ah, gotcha. so the obvious question is, who decides which variables
merit this sort of behaviour and which don't? why two variables out of the DEPLOY_DIR_* variables and not the rest? seems sort of arbitrary.
Who, whoever sends patches with a need.
I know I've used both the DEPLOY_DIR and DEPLOY_DIR_IMAGE before to simplify a few things on the command line.. (but I don't use them regularly).
The others being based on those have not caused me problems the few times I've wanted to override it from the command line.
--Mark
Quoted 4 lines
rday