diff --git a/.gitignore b/.gitignore
index 7bbc71c0..e9292a77 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,7 +9,6 @@ __pycache__/
 # Distribution / packaging
 .Python
 env/
-build/
 develop-eggs/
 dist/
 downloads/
diff --git a/pmb/build/__init__.py b/pmb/build/__init__.py
new file mode 100644
index 00000000..c89d01c7
--- /dev/null
+++ b/pmb/build/__init__.py
@@ -0,0 +1,25 @@
+"""
+Copyright 2017 Oliver Smith
+
+This file is part of pmbootstrap.
+
+pmbootstrap is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+pmbootstrap is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with pmbootstrap.  If not, see <http://www.gnu.org/licenses/>.
+"""
+# Exported functions
+from pmb.build.init import init
+from pmb.build.checksum import checksum
+from pmb.build.other import copy_to_buildpath, is_necessary, \
+    symlink_noarch_package, find_aport, ccache_stats, index_repo
+from pmb.build.package import package
+from pmb.build.menuconfig import menuconfig
diff --git a/pmb/build/autodetect.py b/pmb/build/autodetect.py
new file mode 100644
index 00000000..96b6c437
--- /dev/null
+++ b/pmb/build/autodetect.py
@@ -0,0 +1,64 @@
+"""
+Copyright 2017 Oliver Smith
+
+This file is part of pmbootstrap.
+
+pmbootstrap is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+pmbootstrap is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with pmbootstrap.  If not, see <http://www.gnu.org/licenses/>.
+"""
+import fnmatch
+import pmb.config
+import pmb.chroot.apk
+
+
+def carch(args, apkbuild, carch):
+    if "noarch" in apkbuild["arch"]:
+        return args.arch_native
+    if carch:
+        return carch
+    if ("all" in apkbuild["arch"] or
+            args.arch_native in apkbuild["arch"]):
+        return args.arch_native
+    return apkbuild["arch"][0]
+
+
+def suffix(args, apkbuild, carch):
+    if carch == args.arch_native:
+        return "native"
+    if "noarch" in apkbuild["arch"]:
+        return "native"
+
+    pkgname = apkbuild["pkgname"]
+    if pkgname.endswith("-repack"):
+        return "native"
+    if args.cross and apkbuild["_pmb_build_in_native_chroot"] != "false":
+        for pattern in pmb.config.build_cross_native:
+            if fnmatch.fnmatch(pkgname, pattern):
+                return "native"
+
+    return "buildroot_" + carch
+
+
+def crosscompile(args, apkbuild, carch, suffix):
+    """
+        :returns: None, "native" or "distcc"
+    """
+    if not args.cross:
+        return None
+    if apkbuild["pkgname"].endswith("-repack"):
+        return None
+    if carch == args.arch_native:
+        return None
+    if suffix == "native":
+        return "native"
+    return "distcc"
diff --git a/pmb/build/checksum.py b/pmb/build/checksum.py
new file mode 100644
index 00000000..a7397cb8
--- /dev/null
+++ b/pmb/build/checksum.py
@@ -0,0 +1,36 @@
+"""
+Copyright 2017 Oliver Smith
+
+This file is part of pmbootstrap.
+
+pmbootstrap is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+pmbootstrap is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with pmbootstrap.  If not, see <http://www.gnu.org/licenses/>.
+"""
+import logging
+
+import pmb.chroot
+import pmb.build
+import pmb.helpers.run
+
+
+def checksum(args, pkgname):
+    pmb.build.init(args)
+    pmb.build.copy_to_buildpath(args, pkgname)
+    logging.info("(native) generate checksums for " + pkgname)
+    pmb.chroot.user(args, ["abuild", "checksum"],
+                    working_dir="/home/user/build")
+
+    # Copy modified APKBUILD back
+    source = args.work + "/chroot_native/home/user/build/APKBUILD"
+    target = args.aports + "/" + pkgname + "/"
+    pmb.helpers.run.user(args, ["cp", source, target])
diff --git a/pmb/build/crosscompiler.py b/pmb/build/crosscompiler.py
new file mode 100644
index 00000000..2897c941
--- /dev/null
+++ b/pmb/build/crosscompiler.py
@@ -0,0 +1,32 @@
+"""
+Copyright 2017 Oliver Smith
+
+This file is part of pmbootstrap.
+
+pmbootstrap is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+pmbootstrap is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with pmbootstrap.  If not, see <http://www.gnu.org/licenses/>.
+"""
+import pmb.config
+import fnmatch
+
+
+def init(args, arch):
+    packages = ["gcc-" + arch, "ccache-cross-symlinks"]
+    pmb.chroot.apk.install(args, packages)
+
+
+def native_chroot(args, pkgname):
+    for pattern in pmb.config.crosscompile_supported:
+        if fnmatch.fnmatch(pkgname, pattern):
+            return True
+    return False
diff --git a/pmb/build/init.py b/pmb/build/init.py
new file mode 100644
index 00000000..96ff1281
--- /dev/null
+++ b/pmb/build/init.py
@@ -0,0 +1,78 @@
+"""
+Copyright 2017 Oliver Smith
+
+This file is part of pmbootstrap.
+
+pmbootstrap is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+pmbootstrap is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with pmbootstrap.  If not, see <http://www.gnu.org/licenses/>.
+"""
+import os
+import logging
+
+import pmb.config
+import pmb.chroot
+import pmb.chroot.apk
+import pmb.helpers.run
+
+
+def init(args, suffix="native"):
+    # Check if already initialized
+    marker = "/var/local/pmbootstrap_chroot_build_init_done"
+    if os.path.exists(args.work + "/chroot_" + suffix + marker):
+        return
+
+    # Initialize chroot, install packages
+    pmb.chroot.apk.install(args, pmb.config.build_packages, suffix)
+
+    # Fix permissions
+    pmb.chroot.root(args, ["chmod", "-R", "a+rw",
+                           "/var/cache/distfiles"], suffix)
+
+    # Generate package signing keys
+    chroot = args.work + "/chroot_" + suffix
+    if not os.path.exists(chroot + "/home/user/.abuild/abuild.conf"):
+        logging.info("(" + suffix + ") generate abuild keys")
+        pmb.chroot.user(args, ["abuild-keygen", "-n", "-q", "-a"],
+                        suffix)
+
+        # Copy package signing key to /etc/apk/keys
+        pmb.chroot.root(args, ["cp", "/home/user/.abuild/*.pub",
+                               "/etc/apk/keys/"], suffix)
+
+    # Add gzip wrapper, that converts '-9' to '-1'
+    if not os.path.exists(chroot + "/usr/local/bin/gzip"):
+        with open(chroot + "/tmp/gzip_wrapper.sh", "w") as handle:
+            content = """
+                #!/bin/sh
+                # Simple wrapper, that converts -9 flag for gzip to -1 for speed
+                # improvement with abuild. FIXME: upstream to abuild with a flag!
+                args=""
+                for arg in "$@"; do
+                    [ "$arg" == "-9" ] && arg="-1"
+                    args="$args $arg"
+                done
+                /bin/gzip $args
+            """
+            lines = content.split("\n")[1:]
+            for i in range(len(lines)):
+                lines[i] = lines[i][16:]
+            handle.write("\n".join(lines))
+        pmb.chroot.root(args, ["cp", "/tmp/gzip_wrapper.sh", "/usr/local/bin/gzip"],
+                        suffix)
+        pmb.chroot.root(args, ["chmod", "+x", "/usr/local/bin/gzip"], suffix)
+
+    # Add user to group abuild
+    pmb.chroot.root(args, ["adduser", "user", "abuild"], suffix)
+
+    # Mark the chroot as initialized
+    pmb.chroot.root(args, ["touch", marker], suffix)
diff --git a/pmb/build/menuconfig.py b/pmb/build/menuconfig.py
new file mode 100644
index 00000000..b5e63d29
--- /dev/null
+++ b/pmb/build/menuconfig.py
@@ -0,0 +1,68 @@
+"""
+Copyright 2017 Oliver Smith
+
+This file is part of pmbootstrap.
+
+pmbootstrap is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+pmbootstrap is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with pmbootstrap.  If not, see <http://www.gnu.org/licenses/>.
+"""
+import os
+import logging
+
+import pmb.build
+import pmb.build.autodetect
+import pmb.build.checksum
+import pmb.chroot
+import pmb.chroot.apk
+import pmb.helpers.run
+import pmb.parse
+
+
+def menuconfig(args, pkgname, arch):
+    # Read apkbuild
+    aport = pmb.build.find_aport(args, pkgname, False)
+    if not aport:
+        raise RuntimeError("Package " + pkgname + ": Could not find aport!")
+    apkbuild = pmb.parse.apkbuild(aport + "/APKBUILD")
+
+    # Set up build tools and makedepends
+    pmb.build.init(args)
+    depends = apkbuild["makedepends"] + ["ncurses-dev"]
+    pmb.chroot.apk.install(args, depends, build=False)
+
+    # Patch and extract sources
+    pmb.build.copy_to_buildpath(args, pkgname)
+    logging.info("(native) extract kernel source")
+    pmb.chroot.user(args, ["abuild", "unpack"], "native", "/home/user/build")
+    logging.info("(native) apply patches")
+    pmb.chroot.user(args, ["abuild", "prepare"], "native", "/home/user/build",
+                    log=False)
+
+    # Run abuild menuconfig
+    cmd = []
+    environment = {"CARCH": arch, "TERM": "xterm"}
+    for key, value in environment.items():
+        cmd += [key + "=" + value]
+    cmd += ["abuild", "-d", "menuconfig"]
+    logging.info("(native) run menuconfig")
+    pmb.chroot.user(args, cmd, "native", "/home/user/build", log=False)
+
+    # Update config + checksums
+    logging.info("copy kernel config back to aport-folder")
+    source = args.work + "/chroot_native/home/user/build/src/build/.config"
+    if not os.path.exists(source):
+        raise RuntimeError("No kernel config generated!")
+    target = (args.aports + "/" + pkgname + "/config-" + apkbuild["_flavor"] +
+              "." + arch)
+    pmb.helpers.run.user(args, ["cp", source, target])
+    pmb.build.checksum(args, pkgname)
diff --git a/pmb/build/other.py b/pmb/build/other.py
new file mode 100644
index 00000000..e5a3c282
--- /dev/null
+++ b/pmb/build/other.py
@@ -0,0 +1,166 @@
+"""
+Copyright 2017 Oliver Smith
+
+This file is part of pmbootstrap.
+
+pmbootstrap is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+pmbootstrap is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with pmbootstrap.  If not, see <http://www.gnu.org/licenses/>.
+"""
+import os
+import logging
+import glob
+
+import pmb.chroot
+import pmb.helpers.run
+import pmb.parse.apkindex
+
+
+def find_aport(args, package, must_exist=True):
+    """
+    Find the aport, that provides a certain subpackage.
+
+    :param must_exist: Raise an exception, when not found
+    :returns: the full path to the aport folder
+    """
+    path = args.aports + "/" + package
+    if os.path.exists(path):
+        return path
+
+    for path_current in glob.glob(args.aports + "/*/APKBUILD"):
+        apkbuild = pmb.parse.apkbuild(path_current)
+        if package in apkbuild["subpackages"]:
+            return os.path.dirname(path_current)
+    if must_exist:
+        raise RuntimeError("Could not find aport for package: " +
+                           package)
+    return None
+
+
+def copy_to_buildpath(args, package, suffix="native"):
+    # Sanity check
+    aport = args.aports + "/" + package
+    if not os.path.exists(aport + "/APKBUILD"):
+        raise ValueError("Path does not contain an APKBUILD file:" +
+                         aport)
+
+    # Clean up folder
+    build = args.work + "/chroot_" + suffix + "/home/user/build"
+    if os.path.exists(build):
+        pmb.chroot.root(args, ["rm", "-rf", "/home/user/build"],
+                        suffix=suffix)
+
+    # Copy aport contents
+    pmb.helpers.run.root(args, ["cp", "-r", aport + "/", build])
+    pmb.chroot.root(args, ["chown", "-R", "user:user",
+                           "/home/user/build"], suffix=suffix)
+
+
+def is_necessary(args, suffix, carch, apkbuild):
+    """
+    Check if the package has already been built (because abuild's check
+    only works, if it is the same architecture!)
+
+    :param apkbuild: From pmb.parse.apkbuild()
+    :returns: Boolean
+    """
+
+    # Get new version from APKBUILD
+    package = apkbuild["pkgname"]
+    version_new = apkbuild["pkgver"] + "-r" + apkbuild["pkgrel"]
+
+    # Get old version from APKINDEX
+    version_old = None
+    index_data = pmb.parse.apkindex.read(args, package,
+                                         args.work + "/packages/" + carch + "/APKINDEX.tar.gz", False)
+    if index_data:
+        version_old = index_data["version"]
+
+    if version_new == version_old:
+        return False
+    if pmb.parse.apkindex.compare_version(version_old,
+                                          version_new) == 1:
+        logging.warning("WARNING: Package " + package + "-" + version_old +
+                        " in your binary repository is higher than the version defined" +
+                        " in the APKBUILD. Consider cleaning your package cache" +
+                        " (pmbootstrap zap -p) or removing that file and running" +
+                        " 'pmbootstrap index'!")
+        return False
+    return True
+
+# When arch is not defined, reindex all repos
+
+
+def index_repo(args, arch=None):
+    if arch:
+        paths = [args.work + "/packages/" + arch]
+    else:
+        paths = glob.glob(args.work + "/packages/*")
+
+    for path in paths:
+        path_arch = os.path.basename(path)
+        path_repo_chroot = "/home/user/packages/user/" + path_arch
+        logging.info("(native) index " + path_arch + " repository")
+        commands = [
+            ["apk", "index", "--output", "APKINDEX.tar.gz_",
+             "--rewrite-arch", path_arch, "*.apk"],
+            ["abuild-sign", "APKINDEX.tar.gz_"],
+            ["mv", "APKINDEX.tar.gz_", "APKINDEX.tar.gz"]
+        ]
+        for command in commands:
+            pmb.chroot.user(args, command, working_dir=path_repo_chroot)
+
+
+def symlink_noarch_package(args, arch_apk):
+    """
+    :param arch_apk: for example: x86_64/mypackage-1.2.3-r0.apk
+    """
+
+    # Create the arch folder
+    device_arch = args.deviceinfo["arch"]
+    device_repo = args.work + "/packages/" + device_arch
+    if not os.path.exists(device_repo):
+        pmb.chroot.user(args, ["mkdir", "-p", "/home/user/packages/user/" +
+                               device_arch])
+
+    # Add symlink, rewrite index
+    device_repo_chroot = "/home/user/packages/user/" + device_arch
+    pmb.chroot.user(args, ["ln", "-sf", "../" + arch_apk, "."],
+                    working_dir=device_repo_chroot)
+    index_repo(args, device_arch)
+
+
+def ccache_stats(args, arch):
+    suffix = "native"
+    if args.arch:
+        suffix = "buildroot_" + arch
+    pmb.chroot.user(args, ["ccache", "-s"], suffix, log=False)
+
+
+# set the correct JOBS count in abuild.conf
+def configure_abuild(args, suffix, verify=False):
+    path = args.work + "/chroot_" + suffix + "/etc/abuild.conf"
+    prefix = "export JOBS="
+    with open(path, encoding="utf-8") as handle:
+        for line in handle:
+            if not line.startswith(prefix):
+                continue
+            if line != (prefix + args.jobs + "\n"):
+                if verify:
+                    raise RuntimeError("Failed to configure abuild: " + path +
+                                       "\nTry to delete the file (or zap the chroot).")
+                pmb.chroot.root(args, ["sed", "-i", "-e",
+                                       "s/^" + prefix + ".*/" + prefix + args.jobs + "/",
+                                       "/etc/abuild.conf"], suffix)
+                configure_abuild(args, suffix, True)
+            return
+    raise RuntimeError("Could not find " + prefix + " line in " + path)
diff --git a/pmb/build/package.py b/pmb/build/package.py
new file mode 100644
index 00000000..6b8de703
--- /dev/null
+++ b/pmb/build/package.py
@@ -0,0 +1,114 @@
+"""
+Copyright 2017 Oliver Smith
+
+This file is part of pmbootstrap.
+
+pmbootstrap is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+pmbootstrap is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with pmbootstrap.  If not, see <http://www.gnu.org/licenses/>.
+"""
+import os
+import logging
+
+import pmb.build
+import pmb.build.autodetect
+import pmb.build.crosscompiler
+import pmb.chroot
+import pmb.chroot.apk
+import pmb.chroot.distccd
+import pmb.parse
+import pmb.parse.arch
+
+
+def package(args, pkgname, carch, force=False, recurse=True):
+    """
+    Build a package with Alpine Linux' abuild.
+
+    :param force: even build, if not necessary
+    """
+    # Get aport, skip upstream only packages
+    aport = pmb.build.find_aport(args, pkgname, False)
+    if not aport:
+        if pmb.parse.apkindex.read_any_index(args, pkgname, carch):
+            return
+        raise RuntimeError("Package " + pkgname + ": Could not find aport,"
+                           " and could not find this package in any APKINDEX!")
+
+    # Autodetect the build environment
+    apkbuild = pmb.parse.apkbuild(aport + "/APKBUILD")
+    pkgname = apkbuild["pkgname"]
+    carch_buildenv = pmb.build.autodetect.carch(args, apkbuild, carch)
+    suffix = pmb.build.autodetect.suffix(args, apkbuild, carch_buildenv)
+    cross = pmb.build.autodetect.crosscompile(args, apkbuild, carch_buildenv,
+                                              suffix)
+
+    # Skip already built versions
+    if not force and not pmb.build.is_necessary(args, suffix,
+                                                carch_buildenv, apkbuild):
+        return
+
+    # Build dependencies first
+    if recurse:
+        for depend in apkbuild["depends"]:
+            package(args, depend, carch)
+
+    # Install build tools and makedepends
+    pmb.build.init(args, suffix)
+    if len(apkbuild["makedepends"]):
+        pmb.chroot.apk.install(args, apkbuild["makedepends"], suffix)
+    if cross:
+        pmb.chroot.apk.install(args, ["gcc-" + carch_buildenv,
+                                      "ccache-cross-symlinks"])
+        if cross == "distcc":
+            pmb.chroot.apk.install(args, ["distcc"], suffix=suffix)
+            pmb.chroot.distccd.start(args)
+
+    # Configure abuild.conf
+    pmb.build.other.configure_abuild(args, suffix)
+
+    # Generate output name, log build message
+    output = (carch_buildenv + "/" + apkbuild["pkgname"] + "-" +
+              apkbuild["pkgver"] + "-r" + apkbuild["pkgrel"] + ".apk")
+    logging.info("(" + suffix + ") build " + output)
+
+    # Sanity check
+    if cross == "native" and "!tracedeps" not in apkbuild["options"]:
+        logging.info("WARNING: Option !tracedeps is not set, but we're"
+                     " cross-compiling in the native chroot. This will probably"
+                     " fail!")
+
+    # Run abuild with ignored dependencies
+    pmb.build.copy_to_buildpath(args, pkgname, suffix)
+    cmd = []
+    env = {"CARCH": carch_buildenv}
+    if cross == "native":
+        hostspec = pmb.parse.arch.alpine_to_hostspec(carch_buildenv)
+        env["CROSS_COMPILE"] = hostspec + "-"
+        env["CC"] = hostspec + "-gcc"
+    if cross == "distcc":
+        env["PATH"] = "/usr/lib/distcc/bin:" + pmb.config.chroot_path
+        env["DISTCC_HOSTS"] = "127.0.0.1:" + args.port_distccd
+    for key, value in env.items():
+        cmd += [key + "=" + value]
+    cmd += ["abuild", "-d"]
+    if force:
+        cmd += ["-f"]
+    pmb.chroot.user(args, cmd, suffix, "/home/user/build")
+
+    # Verify output file
+    path = args.work + "/packages/" + output
+    if not os.path.exists(path):
+        raise RuntimeError("Package not found after build: " + path)
+
+    # Symlink noarch packages
+    if "noarch" in apkbuild["arch"]:
+        pmb.build.symlink_noarch_package(args, output)