Gentoo Archives: gentoo-alt

From: Piergiorgio Beruto <piergiorgio.beruto@×××××.com>
To: gentoo-alt@l.g.o
Subject: Re: [gentoo-alt] prefixed gentoo for cross-compile (question)
Date: Wed, 27 Apr 2011 11:29:56
Message-Id: BANLkTikucv3BpZAasvFXOgU-8uJfujm4cg@mail.gmail.com
In Reply to: Re: [gentoo-alt] prefixed gentoo for cross-compile (question) by Michael Haubenwallner
1 Hello Michael,
2
3 2011/4/27 Michael Haubenwallner <haubi@g.o>:
4 > Hi Piergiorgio,
5 >
6 > On 04/26/11 18:10, Piergiorgio Beruto wrote:
7 >> Hi,
8 >> I'm an embedded sw developer already used to gentoo and portage.
9 >
10 > Is your gentoo and portage usage already related to your embedded development?
11 Actually yes, I've been using Gentoo for several years for a wide
12 range of applications (both for my company and on my own) like
13 routers, L2 switches, servers, multimedia and desktop applications. In
14 fact I love gentoo because of its fexibility, like many other users
15 :-)
16
17 Embedded development used to be a different kind of beast, but at
18 company level the requirements for "big" embedded projects are the
19 same as for traditional development and I think it's the time to
20 enhance our ways of working to speed up our daily work and meet the
21 requirements.
22
23 This is why I think portage might be a good solution: in embedded
24 development we're really missing a build system which allows you to
25 pick up traditional open source packages and your own packages
26 maximizing code reuse among projects. I believe portage has the degree
27 of modularity required, and since it's open source is much easier to
28 learn and to maintain.
29
30 >
31 >> I am wondering whether gentoo prefix could help me in the following: I
32 >> would like to use portage to cross compile some base linux packages
33 >> plus some board specific applications for a different number of boards
34 >> each requiring their own patches and packages, with a huge amount of
35 >> code to be shared among them.
36 >
37 > Basically yes, ...
38 >
39 >> I was lookong at crossdev but
40 >
41 > ... however I've not seen anyone trying to make crossdev working in Prefix.
42 >
43 > But I fail to see a reason for crossdev not to work in Prefix, even if
44 > I've not used crossdev myself. So IMO it just has To Be Done (tm).
45
46 Well, I've tried to have crossdev itself working in prefix and I
47 succeeded, the big problem was to cross-build the glibc, then I didnt
48 have the time to finish but maybe I could use some help?
49
50 >
51 >> the big problem is that I CAN'T get
52 >> administrative priviledges on the development machine, in fact each
53 >> user at the moment builds the packages in their own home.
54 >
55 > This is one of the reasons Gentoo Prefix was born.
56 >
57 >> To be more precise I wish I could use portage installed in my home
58 >> directory and have it use some cross-toolchain (either pre-built or
59 >> built through portage) to actually download, patch, configure, build
60 >> and install packages to some directory which will eventually be turned
61 >> into a target filesystem someway.
62 >> I've tried to use crossdev inside prefixed gentoo but failed to have
63 >> it working and I'm not sure it's the correct approach anyway.
64 >
65 > The special use case for Prefix here IMO is the combination of
66 > ROOT="/somewhere" with EPREFIX="" and non-Prefix profiles/keywords.
67 Yes, crossdev already uses the ROOT variable to specify the
68 installation path, I'm not yet very familiar with prefix related
69 variables so it might only be a matter of studying...
70 For instance what you mean exactly by "non-Prefix profiles/keywords"?
71 >
72 >> Have you guys any suggestion about my problem? That would save a lot
73 >> of users to keep developing new build systems and re-inventing the
74 >> wheel each time! Also they would never come to something as good and
75 >> featured as portage.
76 >
77 > For what I can say if I were in your situation:
78 >
79 > First, I'd try crossdev on some (virtualized) vanilla Gentoo Linux
80 > system, to see if crossdev /is/ the tool doing what I need, and to
81 > see how it works.
82 Yes, I'm already a crossdev user and I actually think it could be the
83 tool I am looking for, possibly with some tweaks.
84 >
85 > Then I'd try to fix crossdev to work within Gentoo Prefix, trying
86 > to get identical output as on the vanilla Gentoo Linux system.
87 That's the difficult part :)
88 >
89 > But I also would expect lots of work, resulting in patches for crossdev,
90 > ebuilds/eclasses, as well as (prefix-)portage.
91 That's what I am NOT familiar with, I am an experienced portage user
92 but not (yet) a good portage developer.
93 Maybe I could use a little help with this? Do you guys find this kind
94 of development useful/challenging? In which case, have you got a rough
95 idea about the effort in making a working prototype (your guess would
96 be much better then mine)?
97
98 Oh, one last thing: one of the big issues is about host machines... it
99 would be nice if the prefixed Gentoo could be portable across
100 different development machines / users. Do you think it's possible to
101 have a prefixed gentoo "relocatable"? I mean, I setup my prefixed
102 system, then i "tar cvj" the entire system then untar for a different
103 user / different machine, "change some config files / environment
104 variables" and have my prefixed system work without bootstrapping
105 again?
106
107 Thank you very much for your time and help,
108 Regards,
109
110 Piergiorgio
111
112 >
113 > HTH,
114 > /haubi/
115 > --
116 > Michael Haubenwallner
117 > Gentoo on a different level
118 >
119 >

Replies

Subject Author
Re: [gentoo-alt] prefixed gentoo for cross-compile (question) Ramon van Alteren <ramon@××××××××××.nl>
Re: [gentoo-alt] prefixed gentoo for cross-compile (question) Michael Haubenwallner <haubi@g.o>