Arch Linux

r-darwish

Member

Registered: 2013-12-16

Posts: 12

Creating an Arch USB key with Windows installer

I'm trying to make an Arch USB key which can also boot the Windows 10 installer. I followed the steps in https://wiki.archlinux.org/index.php/In … _a_USB_key and created a GPT partition table with a boot partition and an encrypted root partition. I boot the key using Syslinux and everything works fine.

Now I got to the part where I try to embed the Windows 10 installer. I created a third FAT32 partition, mounted it and used rsync to copy all files from the Windows 10 installation ISO to that partition. Now comes the part when I edit syslinux.cfg. If I add something like that:

LABEL windows
MENU LABEL Windows 10 Installation
COM32 chain.c32
APPEND label=windows

Then it doesn't work, which makes sense since I just copied the files from the Windows ISO without using anything to write NTLDR to that partition boot sector. However, when I try this instead:

LABEL windows
MENU LABEL Windows 10 Installation
COM32 chain.c32
APPEND label=windows ntldr=/bootmgr

Then syslinux complains that it can't find the boot file, although bootmgr exists in the Windows partition. Out of curiosity I copied bootmgr to my /boot partition containing  syslinux, then tried the above configuration. syslinux booted NTLDR which complained that it can't find its BCD file. This is the part where I got confused. If I do specify a different partition than my /boot partition, how come syslinux still assumes that /bootmgr is located in the /boot partition?

Also, can I write NTLDR to the FAT32 partition's boot sector without using a Microsoft utility?