[gentoo-user] crossdev setup questions for distcc usage

[gentoo-user] crossdev setup questions for distcc usage

[Walter Dnes]

  Probably the first of many.  I emerged crossdev on my 64-bit PC.  When
I ran "crossdev -t --help", it wanted an overlay, and pointed me to
https://wiki.gentoo.org/wiki/Overlay/Local_overlay which led me to...

mkdir -p /usr/local/portage/{metadata,profiles}
echo 'netbook' > /usr/local/portage/profiles/repo_name
echo 'masters = gentoo' > /usr/local/portage/metadata/layout.conf
chown -R portage:portage /usr/local/portage
echo 'PORTDIR_OVERLAY="/usr/local/portage ${PORTDIR_OVERLAY}"' >> /etc/portage/make.conf

  I now have a line...

PORTDIR_OVERLAY="/usr/local/portage ${PORTDIR_OVERLAY}"

...in /etc/portage/make.conf wich leads to a few questions...

1) Given that I don't have PORTDIR_OVERLAY previously defined, can I
safely cut down that line to...
PORTDIR_OVERLAY="/usr/local/portage"

2) Does this imply that one can have multiple, space-separated,  overlays
PORTDIR_OVERLAY="/usr/local/portage /fu/bar /whatever/wherever"

-- 
Walter Dnes <waltdnes@waltdnes.org>
I don't run "desktop environments"; I run useful applications

Re: [gentoo-user] crossdev setup questions for distcc usage

[Walter Dnes]

[-- Attachment #1: Type: text/plain, Size: 304 bytes --]

  Next step was "crossdev -t -S i686-pc-linux-gnu".  One thing I'm
worried about; the default is stage 4, but the output mentions...
"Emerging cross-gcc-stage2".  Is this a problem?  See attached file

-- 
Walter Dnes <waltdnes@waltdnes.org>
I don't run "desktop environments"; I run useful applications

[-- Attachment #2: x.txt --]
[-- Type: text/plain, Size: 1929 bytes --]

[d531][root][~] crossdev -t -S i686-pc-linux-gnu
--------------------------------------------------------------------------------
 * crossdev version:      20140917
 * Host Portage ARCH:     amd64
 * Target Portage ARCH:   x86
 * Target System:         i686-pc-linux-gnu
 * Stage:                 4 (C/C++ compiler)
 * ABIs:                  default

 * binutils:              binutils-[latest]
 * gcc:                   gcc-[latest]
 * headers:               linux-headers-[latest]
 * libc:                  glibc-[latest]

 * CROSSDEV_OVERLAY:      /usr/local/portage
 * PORT_LOGDIR:           /var/log/portage
 * PORTAGE_CONFIGROOT:    
 * Portage flags:         
  _  -  ~  -  _  -  ~  -  _  -  ~  -  _  -  ~  -  _  -  ~  -  _  -  ~  -  _  -  
 * leaving metadata/layout.conf alone in /usr/local/portage
  _  -  ~  -  _  -  ~  -  _  -  ~  -  _  -  ~  -  _  -  ~  -  _  -  ~  -  _  -  
 * Log: /var/log/portage/cross-i686-pc-linux-gnu-binutils.log
 * Emerging cross-binutils ...                                            [ ok ]
 * Log: /var/log/portage/cross-i686-pc-linux-gnu-linux-headers-quick.log
 * Emerging cross-linux-headers-quick ...                                 [ ok ]
 * Log: /var/log/portage/cross-i686-pc-linux-gnu-glibc-headers.log
 * Emerging cross-glibc-headers ...                                       [ ok ]
 * Log: /var/log/portage/cross-i686-pc-linux-gnu-gcc-stage1.log
 * Emerging cross-gcc-stage1 ...                                          [ ok ]
 * Log: /var/log/portage/cross-i686-pc-linux-gnu-linux-headers.log
 * Emerging cross-linux-headers ...                                       [ ok ]
 * Log: /var/log/portage/cross-i686-pc-linux-gnu-glibc.log
 * Emerging cross-glibc ...                                               [ ok ]
 * Log: /var/log/portage/cross-i686-pc-linux-gnu-gcc-stage2.log
 * Emerging cross-gcc-stage2 ...                                          [ ok ]
[d531][root][~] 

[gentoo-user] Re: crossdev setup questions for distcc usage

[James]

Walter Dnes <waltdnes <at> waltdnes.org> writes:



> PORTDIR_OVERLAY="/usr/local/portage ${PORTDIR_OVERLAY}"


PORTDIR is deprecated, from my understanding as to the new
schemes for repos and the namespaces[1]. We're in a transition,
so this might be an excellent issue to flush out  with the devs[2].


As soon as you (cross)compile with more than one
core, things that work and do not work seem to often be ambiguous
on the results. From what I've experienced over the years and read,
it may be best to keep the flag setting extremely conservative
and test your results before using more aggressively experimental
configurations. I have not done much of this since I built some
i586 (amd&intel) binaries for minimized gentoo systems quite a few
years ago.


I'm interested in exactly what you are doing, plus extending the 
cross compile to arm architectures and running on top of clusters
of gentoo systems; please continue to post back what you discover.
For this sort of (cluster compiling) experimentation, folks build custom
'frameworks' so you might have some luck adding 'framework' to your keyword
searches related to distributed compiling.

I have several old 586 and 686 based systems laying around,
so I can duplicate and verify your results if you like. Also, lots 
of linux distros compile for target 386 binaries so they run everywhere; it
might be a good resources if you can find where one of those niche linux
distros describe how they cross compile for their periodic releases.

ZeroChaos (gentoo dev) releases i686 codes for pentoo, so that might be
another source of expertise you can use as a guide.[3]


hth,
James


[1] {gentoo-dev} Naming of repositories (3/14/15)

[2] https://wiki.gentoo.org/wiki/Project:Portage/Sync

[3] http://www.pentoo.ch/download/tools_list_i686_2014_0_RC3_5

Re: [gentoo-user] Re: crossdev setup questions for distcc usage

[Walter Dnes]

On Fri, Mar 20, 2015 at 02:02:19PM +0000, James wrote

> I'm interested in exactly what you are doing, plus extending the
> cross compile to arm architectures and running on top of clusters
> of gentoo systems; please continue to post back what you discover.
> For this sort of (cluster compiling) experimentation, folks build
> custom 'frameworks' so you might have some luck adding 'framework'
> to your keyword searches related to distributed compiling.

  I'm simply trying to offload compiling from my ancient, underpowered
netbook (14 hours to build seamonkey!!!) to my desktop.  I'd like to be
able to transparently run "emerge" from the netbook, have the desktop
machine do the grunt work, and install the compiled binaries and
associated /etc/* files on the netbook.  This assumes both machines are
connected on my home LAN.

  Since you mentioned arm architectures, it's ironic that the wiki
crossdev instructions now point to the embedded cross-compiler site
http://www.gentoo.org/proj/en/base/embedded/handbook/

  I've followed the instructions chapter 2 for installing crossdev and
it appears to work.  Note that my desktop machine is a 64-bit install...

=======================================================================
[d531][root][~] i686-pc-linux-gnu-gcc --version
i686-pc-linux-gnu-gcc (Gentoo 4.9.2 p1.2, pie-0.6.2) 4.9.2
Copyright (C) 2014 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

[d531][root][~] echo 'int main(){return 0;}' > ctest.c
[d531][root][~] i686-pc-linux-gnu-gcc -Wall ctest.c -o ctest
[d531][root][~] file ctest
ctest: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux.so.2, for GNU/Linux 2.6.32, not stripped
[d531][root][~]
=======================================================================

  I'm now reading up on...
https://wiki.gentoo.org/wiki/Distcc/Cross-Compiling
https://wiki.gentoo.org/wiki/Distcc

...to figure out how to launch it from my netbook.

-- 
Walter Dnes <waltdnes@waltdnes.org>
I don't run "desktop environments"; I run useful applications