libdevuansdk/docs/helper_functions.7.md

helper functions

you can find useful helper functions in libdevuansdk/zlibs/helpers. they are intended to help you with writing wrappers, as well as making my job easier within developing libdevuansdk. some of these functions are required for libdevuansdk to properly work as well.

build_arm_dist()

this function is kind of a wrapper function, mostly used in arm-sdk to build a complete "dd-able" image from start to end. to run, it requires $workdir $strapdir, and $os, $arch, $size, $parted_type, $bootfs, defined. additionally, $dos_root, $dos_boot if $parted_type=dos, or $gpt_root, $gpt_boot if $parted_type=gpt. see creating_wrappers(7) for insight on these variables.

the workflow of this function is bootstrapping a complete rootfs, creating a raw image, installing/compiling a kernel, rsyncing everything to the raw image, and finally, compressing the raw image.

devprocsys()

this function is a simple helper function that takes two arguments: watdo and werdo. it mounts or umounts /sys, /dev, /dev/pts, and procfs where you tell it to. for example:

devprocsys mount $strapdir
devprocsys umount $strapdir

findloopmapp()

this functions takes the raw image and finds a free loopdevice for it to be mounted. it calls losetup(8) and kpartx(8).

qemu_install_user()

helper function to install the userspace qemu to $strapdir.

dpkgdivert()

this one takes two arguments, watdo and werdo (much like devprocsys). it will create a dpkg diversion in the place you tell it to and remove invoke-rc.d so that apt doesn't autostart daemons when they are installed.

enablessh()

this function will allow root login with password in the bootstrapped rootfs.

chroot-script()

allows you to chroot inside the $strapdir and execute the script/binary that's given to it. takes an optional argument: -d (will call dpkgdivert on and off)

silly()

a funny function printing out random messages.