For a real toaster with an ARM chip, Alex changed MACHINE = "raspberrypi4" in local.conf . For a custom driver, Alex wrote a new recipe (a .bb file) telling Yocto how to fetch, compile, and install that driver.
NOTE: Tasks Summary: Attempted 1243 tasks of which 0 didn't need to be rerun NOTE: Build complete. In the tmp/deploy/images/qemux86-64/ folder lay a file: core-image-minimal-qemux86-64.ext4 . A perfect, custom-baked Linux system. To test his creation, Alex didn't need real hardware yet. Yocto comes with a virtual oven called QEMU .
For years, Alex used the same method. He would take a generic, pre-made Linux distribution, strip out the parts he didn’t need, and cram it onto his tiny device.
bitbake core-image-minimal The terminal exploded into a waterfall of text. Very slow. Alex watched as Yocto downloaded source code for the Linux kernel, the C library, and thousands of tools. It fetched, patched, configured, compiled, and packed.
git clone git://git.yoctoproject.org/poky cd poky The elder pointed to a strange incantation. "Before you bake, you must set the table. Run this magic command every time you enter your kitchen."
in the bustling town of Embedded Valley, there was a baker named Alex. Alex didn’t bake ordinary bread. Alex baked the operating system for smart toasters, wearable fitness trackers, and autonomous garden sprinklers.
Poky (Yocto Project Reference Distro) 4.0 /dev/ttyS0 qemux86-64 login:
MACHINE = "qemux86-64" IMAGE_FS_TYPE = "ext4" "Now for the fun part," the elder grinned. "Tell Yocto what kind of loaf you want."
