---
breadcrumbs:
- - /chromium-os
  - Chromium OS
- - /chromium-os/build
  - Chromium OS Build
page_name: sdk-config-management
title: SDK Config Management
---

## SDK Config Files Overview

Portage and Chromite libraries use various make.conf files to store and retrieve
SDK configurations.

*   `/etc/make.conf`
    *   symlinked to
        [src/third_party/chromiumos-overlay/chromeos/config/make.conf.amd64-host](https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/main/chromeos/config/make.conf.amd64-host)
    *   Overall make.conf for the SDK “board.”
    *   Sources the other `make.conf.*` files to pull in additional config.
    *   Treated by
        [sysroot_lib](https://chromium.googlesource.com/chromiumos/chromite/+/HEAD/lib/sysroot_lib.py)
        in Chromite as the source to read configuration from as it contains the
        full picture.
*   `/etc/make.conf.board_setup`
    *   Generated by `cros_sysroot_utils` with references to amd64-host sysroot
        removed.
    *   Declares `BOARD_OVERLAY` and `CHOST`.
    *   Treated by
        [sysroot_lib](https://chromium.googlesource.com/chromiumos/chromite/+/HEAD/lib/sysroot_lib.py)
        as where to write additional configuration.
*   `/etc/make.conf.host_setup`
    *   Created by
        [update_chroot](https://chromium.googlesource.com/chromiumos/platform/crosutils/+/HEAD/update_chroot)
        each time the SDK is updated.
