mkosxinstallusb

Linux shell script that creates bootable USB flash drive with OS X installer.

OS X installer application contains a disk image "InstallESD.dmg" that can be used to create a bootable USB flash drive. The procedure is well described in the media, see references below.

This script automates process on Linux platform, doing essentially the following:

mkdir -p /mnt/OSX_InstallESD /mnt/OSX_BaseSystem /mnt/usbstick

# convert installer disk image to raw format
dmg2img "Install OS X <Version>.app/Contents/SharedSupport/InstallESD.dmg" InstallESD.img
kpartx -a InstallESD.img
mount /dev/mapper/loop0p2 /mnt/OSX_InstallESD

# convert base system disk image to raw format
dmg2img /mnt/OSX_InstallESD/BaseSystem.dmg BaseSystem.img
kpartx -a BaseSystem.img
mount /dev/mapper/loop1p1 /mnt/OSX_BaseSystem

# partition the USB flash drive, /dev/sdX
sgdisk -o /dev/sdX
sgdisk -n 1:0:0 -t 1:AF00 -c 1:"disk image" -A 1:set:2 /dev/sdX
mkfs.hfsplus -v "OS X Base System" /dev/sdX1
mount /dev/sdX1 /mnt/usbstick

# copy installer files
rsync -aAEHW /mnt/OSX_BaseSystem/ /mnt/usbstick/
rm -f /mnt/usbstick/System/Installation/Packages
rsync -aAEHW /mnt/OSX_InstallESD/Packages /mnt/usbstick/System/Installation/
rsync -aAEHW /mnt/OSX_InstallESD/BaseSystem.chunklist /mnt/usbstick/
rsync -aAEHW /mnt/OSX_InstallESD/BaseSystem.dmg /mnt/usbstick/
sync

Usage: ./mkosxinstallusb.sh </dev/sdX> "Install OS X <Version>.app", where </dev/sdX> is a block device for target USB flash drive, e.g. /dev/sdb.

Known problems:

High Sierra installers are not supported yet,
Korean localization can be omitted due to Linux/hfsplus bug, see https://ubuntuforums.org/showthread.php?t=1422374

References:

eprigorodov/mkosxinstallusb

mkosxinstallusb