[SOLVED] How to find the target triplet?

tcymtz · 11-01-2014, 07:32 PM

Hello, I am on step 5.2 of LFS and I have hit another snag. He wants me to find the target triplet before continuing:

Code:

Before continuing, be aware of the name of the working platform,
often referred to as the target triplet. A simple way to determine the
name of the target triplet is to run the config.guess script that comes
with the source for many packages. Unpack the Binutils sources and run
the script: ./config.guess and note the output. For example, for a modern
32-bit Intel processor the output will likely be i686-pc-linux-gnu.

I am unfamiliar with unpacking in linux, so I made a temp folder to practice in and copied the 3 binutils* files from sources into it. I looked up unpacking on Google but I am just getting errors. Not sure what I am doing wrong. Can someone tell me which of the following 3 files I need to unpack to get the target triplet:

binutils-2.24-load_gcc_lto_plugin_by_default-1.patch
binutils-2.24-lto_testsuite-1.patch
binutils-2.24.tar.bz2

And also, what is the command to unpack it/them?

Lastly, when I do unpack it/them, do I just type './config.guess' while I am in my 'temp' folder and I will see the target triplet?

Thank you.

stoat · 11-01-2014, 09:16 PM

The one to "unpack" is the tar.bz2 file (aka tarball). It contains the source code tree archived in a bzipped tarball. You unpack (or untar) it by opening a terminal, changing directories to where it's located, and using the tar command on it like this...

Code:

tar xf binutils-2.24.tar.bz2

After a few seconds, the prompt returns. Then change directories to the new directory created by untarring the tarball and run the config.guess command. Like this...

Code:

cd binutils-2.24
./config.guess
i686-pc-linux-gnu <--my result on this machine

All of this is just sort of educational. You don't do anything with this information. It's so you'll realize that the LFS_TGT variable is intentionally slightly different from the actual triplet name that you just discovered. That causes the first builds of Binutils and GCC to result in a cross-compiler which by definition is not linked to anything in the host system. It's the key strategy of the LFS method for distancing the tools built in chapter 5, and ultimately the finished LFS system, from the libraries and headers of the host system.

tcymtz · 11-01-2014, 10:07 PM

Cool. I got it all to work. Thanks for explaining that. It was very helpful.