IMX Hello World

Hello, World!

Yocto references

- Yocto Project Application Developer's Guide 2.1
- See the "Build Yocto from source code" section in this Wiki website, for your appropriate board and Yocto release.

Sample C "Hello, world!" program

Create a file called myhello.c with the following content:

#include <stdio.h>

int main() {
	printf("Hello, World!\n");
	return 0;
}

Building out of Yocto

Toolchain installation for out of Yocto builds

To install the toolchain:
For Variscite's MX6 boards, follow VAR-SOM-MX6 Toolchain installation for out of Yocto Krogoth builds.
For DART-6UL, follow DART-6UL Toolchain installation for out of Yocto Krogoth builds.
For VAR-SOM-MX7, follow VAR-SOM-MX7 Toolchain installation for out of Yocto Krogoth builds.

Build

Source the environment setup script (see the previous "Toolchain installation" section)

Compile:
$ $CC $CFLAGS $LDFLAGS myhello.c -o myhello

Now you should have an app called myhello, that can be copied (using scp, for example) and run on your target board.

Building using Yocto

Sample bitbake recipe of an "Hello, world!" application

Create a file called myhello.bb with the following content:

DESCRIPTION = "Simple helloworld application"
LICENSE = "MIT"
LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"

SRC_URI = "file://myhello.c"

S = "${WORKDIR}"

do_compile() {
	${CC} ${CFLAGS} ${LDFLAGS} myhello.c -o myhello
}

do_install() {
	install -d ${D}${bindir}
	install -m 0755 myhello ${D}${bindir}
}

Create the following directory tree under your Yocto directory, and place in it the two files described above:

sources/meta-variscite-imx/recipes-examples/
└── myhello
    ├── files
    │   └── myhello.c
    └── myhello.bb

2 directories, 2 files

Build

Run the following in your Yocto build directory:

$ bitbake myhello

To find the location of the output package you can run the following in your Yocto build directory:

$ cd tmp/deploy/rpm
$ find -name myhello*

To add the output of this recipe to your output images, add the following to your conf/local.conf file in your Yocto build directory:

IMAGE_INSTALL_append = " myhello"

This will put the myhello app in your rootfs.