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plaes | 7 years ago

Why bother?

  apt install gcc-arm-linux-gnueabihf # Debian / Ubuntu
  dnf install gcc-arm-linux-gnu # Fedora

discuss

order

yorwba|7 years ago

I recently built a cross-compiler for a used Kindle 3 I got from a friend. Its kernel is from 2008, but you can still read books with it just fine. I was thinking about turning it into a mobile terminal I can use in full sunshine (e-ink is rad) and using precompiled hacks from the mobilereads forums, I got ssh on the device pretty quickly.

But as soon as I wanted to compile my own binaries, things weren't so easy anymore. The glibc on there is too ancient for modern cross-compilers (like the one installed by apt). It can't be replaced because the kernel is too ancient for a modern glibc. Replacing the kernel would probably fail due to lack of compatible drivers.

The sources for the original cross-compiler, the kernel and various libraries were actually quite easy to find on Amazon's website, but they were incredibly difficult to build. Because that GCC used some GNU C extensions that changed semantics in modern GCCs, it didn't even compile without patching the source. The build step for glibc involved filtering the assembly produced by the compiler through a sed script, which of course silently failed when the newer compiler produced different output.

All in all, it took me about two weeks of experimentation until I had a working cross-toolchain.

stuaxo|7 years ago

Did you put this up somewhere ?

There are probably at least a couple of other people who might find it usefl.

alex7o|7 years ago

I did something similar for kindle 4, and it wasn't that hard, i just had to patch a few of the makefiles and i got gcc, but i was unable to then build that to run on the kindle.

nerdponx|7 years ago

Wouldn't this madness be solved by documenting the versions of the various required tools?

lisper|7 years ago

Give me a binary and I hack for a day. Teach me to build a binary and I code for a lifetime.

(Just in case you didn't get the allusion: https://quoteinvestigator.com/2015/08/28/fish/)

amelius|7 years ago

You mean:

Teach me how to build a compiler binary, and I'll be building compiler binaries for a lifetime.

which is somewhat less inspirational. Even less so when replacing "compiler binary" by "other people's code".

I think the main problem with your analogy is that in IT, the "fish" are free.

ggm|7 years ago

Give me a binary and I run it. Teach me to build the binary and I am fixing bugs for a lifetime.

HankB99|7 years ago

Unrelated variant: Give a man fire and he'll be warm for a night. Set a man on fire and he'll be warm the rest of his life.

;)

efficax|7 years ago

lol you explained the fishing proverb

jimmies|7 years ago

I found cross-compiling makes linking with weird stuff, for example, the raspberry pi's proprietary Broadcom libs hard. You can chroot directly to a raspberry pi image using a simple script with qemu-user-static-arm, and that will guarantee 100% linking compatibility.

0xfeba|7 years ago

I found the same for anything remotely complicated. I prefer just using a VM.

nightcracker|7 years ago

If you need any configuration options different than the packages provide, or a version later than the packages provide.

ufo|7 years ago

The article mentions the need to account for a different version of glibc in Raspbian. Does this solution also solve this problem, or do you need to also use the same version of Debian on your main machine?

pletnes|7 years ago

From my experience, compiling on a machine with an older version of linux/glibc should work fine. The other way, not so much.

mmphosis|7 years ago

Now I need to install apt and whatever dnf is and whatever dependencies they have and so on...

fragmede|7 years ago

Do people still fight with dependencies?

Apt or dnf or some other package manager (like yum or pacman) comes preconfigured and preinstalled on all but the most esoteric Linux distros, so unless you're doing some really esoteric stuff, if you're fighting with dependencies, I would assume something's gone wrong.

Which is to say, it still certainly possible to fall into dependency hell in this day and age, but the parent response belies a certain level of fear of installing things on Linux because of dependencies. I hear Windows still has this problem, decades later, and while Linux has it's own share of foibles, installing pre-packaged software is generally not the exciting/frustrating part. (Which Docker has made even easier!)

auscompgeek|7 years ago

Uh, why would you install a system package manager when you already have one?