Compiling the Amazon toolchain?

[katadelos]

I've been trying to follow these instructions from TOOLCHAIN_BUILD_HOW-TO.txt in order to build a toolchain that is able to compile kernel modules for my firmware:

Building the Toolchain

To build the toolchain, You need to setup a poky 1.8.1 environment

To setup environment:

Clone Poky 1.8.1 by following the instruction from https://www.yoctoproject.org/downloads/core/fido181

Execute the folling command to setup a environment
$ source poky/oe-init-build-env build
$ cd build

To build toolchain,execute the follwing command after setting up an environment

$ bitbake gcc-cross

The link to yoctoproject.org is dead but was archived by the Wayback Machine, which led me to a download link for poky-fido-13.0.1.tar.bz2. After decompressing the file, setting up an environment and running bitbake gcc-cross, bitbake throws this error:

WARNING: Host distribution "Ubuntu-18.04" has not been validated with this version of the build system; you may possibly experience unexpected failures. It is recommended that you use a tested distribution.
Parsing recipes: 100% |########################################| Time: 00:01:05
Parsing of 884 .bb files complete (0 cached, 884 parsed). 1285 targets, 41 skipped, 0 masked, 0 errors.
ERROR: Nothing PROVIDES 'gcc-cross'. Close matches:
gcc-cross-i586

Summary: There was 1 WARNING message shown.
Summary: There was 1 ERROR message shown, returning a non-zero exit code.

I tried bitbake gcc-cross-i586, but this seems to target a different architecture completely and fails when attempting to compile automake. Has anyone been able to compile a toolchain using the provided instructions?

[NiLuJe]

I don't think anyone here ever went with bitbake, but I did notice that file, and that it pointed to a wonderfully outdated yocto tag .

FWIW, the current link for that is probably on https://www.yoctoproject.org/softwar...ived-releases/

People building a whole bunch of stuff have gone with BuildRoot in the past, but I've personally only ever used crosstool-ng and then basically scripted stuff myself.

If you only need a TC, and not actually a giant "build-me-a-distro" machinery, c.f., https://github.com/koreader/koxtoolchain which is basically a frontend to my setup.

If you intend to build kernel modules (and only modules), you *may* need something using a GCC version closer to what's used to build your device's kernel. I personally don't have a config for that on Kindle (but I do for Kobos).

[katadelos]

Just following this up in case anyone else is interested: @NiLuJe's toolchain is suitable for compiling Linux kernel modules, but you need to make a small tweak to the Linux sources first (at least for 3.0.35).

When compiling a module for the first time, I encountered this error:

  CHK     include/linux/version.h
  CHK     include/generated/utsrelease.h
make[1]: 'include/generated/mach-types.h' is up to date.
  CC      kernel/bounds.s
In file included from include/linux/compiler.h:48:0,
                 from include/linux/stddef.h:4,
                 from include/linux/posix_types.h:4,
                 from include/linux/types.h:17,
                 from include/linux/page-flags.h:8,
                 from kernel/bounds.c:9:
include/linux/compiler-gcc.h:94:1: fatal error: linux/compiler-gcc7.h: No such file or directory
 #include gcc_header(__GNUC__)
 ^~~~
compilation terminated.
/home/ubuntu/linux3/./Kbuild:35: recipe for target 'kernel/bounds.s' failed
make[1]: *** [kernel/bounds.s] Error 1
Makefile:990: recipe for target 'prepare0' failed
make: *** [prepare0] Error 2

This is simple to fix - all you need to do is create a hard link to the file that the compiler is expecting to find:

ln include/linux/compiler-gcc4.h include/linux/compiler-gcc7.h

Once this is done, you should be good to go.

[NiLuJe]

Yeah, FWIW, I've had to jump through a few hoops with older kernel releases on Kobo, too, even when using a GCC 4.9 TC.

Mostly simple/stupid fixes which are usually pretty obvious once you grok the error message .

Good to know that modules built w/ GCC 7 worked out fine, though .

And that Amazon finally stopped shipping kernel sources with missing non-trivial headers (because that was a thing at one point ^^).