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hey everyone, |
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I know i've been lurking as of late, but i'm going to try and get some |
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more time to put into gentoo soon. For now I thought i'd actually |
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submit some documentation pieces I've been saying I'd submit for a |
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long time ;-) |
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|
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About 6 months ago I submitted some patches to catalyst that lets you |
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perform basic tasks to get a minimal gentoo image. I didn't submit |
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any documentation, but I did submit a simple spec file. |
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|
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I'm not sure if this is enough for people or not, but I'll explain |
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things further here. |
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|
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Make sure you have read all the catalyst information thoroughly before |
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you read this. |
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|
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Using Catalyst for Embedded System Building |
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|
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Catalyst spec files for livecd's and stages are almost identical to |
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the embedded spec files. |
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|
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The immediate difference is that there is no dependancy checking for |
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embedded spec files. The decision was made to not calculate |
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dependancies because the 'embedded' ebuilds don't have a real |
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dependancy tree. This may change in the future as we hopefully move |
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to cascading profiles, so currently do all the dependancy checking |
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yourself. Secondly, when packages are emerged inside the build |
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enviornment they are emerged into a subdirectory of that enviornment |
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using the ROOT enviornment variable. This has problems of it's own |
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which I will not discuss here. |
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|
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A simple embedded spec file might look something like this: |
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|
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subarch: x86 |
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version_stamp: embedded |
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target: embedded |
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rel_type: embedded |
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rel_version: 1.4 |
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snapshot: embedded |
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source_subpath: default-x86-1.4/stage1-x86-1.4 |
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|
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embedded/runscript: scripts/initrd.sh |
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embedded/use: |
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static |
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links |
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-devfs |
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initrd |
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embedded/rm: |
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/usr/share/doc |
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/usr/share/man |
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/var/db/pkg |
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/var/edb |
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embedded/packages: |
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sys-apps/baselayout-lite |
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=sys-apps/busybox-0.60.5-r2 |
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|
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The top portion of the file looks similar to a standard catalyst |
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file, that specifies the starting stage and what kind of profile you |
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are building. The other lines represent: |
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|
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embedded/runscript: This specifies a script to be run after the bulid |
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process is complete. Included with catalyst, is this script |
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initrd.sh which puts the system into an ext2 filesystem and gzip's |
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it. |
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|
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embedded/use: Specifies all the use variables for this build. |
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|
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embedded/rm: Tells catalyst which directories to remove after |
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building is complete. Great for getting rid of include headers and |
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man pages. |
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|
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embedded/packages: Specifies which packages and package versions to |
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install on the image |
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|
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--------- |
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|
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Well that's most of what I had lying around in terms of |
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documentation. It is definatly far from complete, but suggestions and |
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comments are welcome. Eventually this should make it to guide xml! |
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