[Aboriginal] [landley/aboriginal] cross-compile for ARM based embedded system running busybox (#4)

[Rob Landley]

On 11/29/2016 03:24 PM, erdosnew wrote:
> hi, i found about aboriginal through busybox,
> https://busybox.net/FAQ.html#build

Hello.

> i've got an ARM-based system running busybox. and i'm trying to learn
> how to compile simple programs for it. the examples i use were from
> busybox-tiny utilities (i.e. Dropbear SMTP, ntpclient).
> 
> i downloaded prebuilt compiler for arm to my linux machine
> (http://landley.net/aboriginal/downloads/binaries/cross-compiler-armv6l.tar.gz)
> and unzipped into a working directory.

Use armv5l, it's backwards compatibleand the system image works. The
armv6l target won't boot under qemu due to kernel version skew. (The
kernel needed a patch I stopped forward porting.)

> what i'm not sure is how to cross compile the program on my linux machine.
> i navigated to directory containing 'ntpclient' and run the following:
> 
> CROSS_COMPILE="$PWD/cross-compiler-armv5l/bin/armv6l-"

v5 vs v6 doesn't match?

> CROSS_COMPILE="$CROSS_COMPILE" make

You could should need to set it to itself, you can just do:

  CROSS_COMPILE="$PWD/cross-compiler-armv6l/bin/armv6l-" make

> but the resulted 'ntpclient' executable seems still is for linux instead
> of 'arm' (it won't run on my embedded system).

I dunno what ntpclient package you're trying to build. In theory if it's
listening to CROSS_COMPILE the build should die if you point it at a
nonexistent file. So possibly that package doesn't know about the
CROSS_COMPILE variable?

> need some pointers on how to use aborginal Prebuilt Binaries.

These days I'm migrating to http://github.com/richfelker/musl-cross-make
toolchains, but haven't had time to work on this recently. ($DAYJOB is
in frantic deadline mode, I'm a week into a 2-week stay in san
francisco, then I head to san diego for 2 weeks, then I get back to
austin long enough to start a road trip to visit family for christmas...)

Rob