NTloader
Ntloader is a bootloader for NT6+ WIM, VHD and VHDX images.
Compatibility
Ntloader supports BIOS (i386) and UEFI (i386, x86_64, arm64) environments.
The hybrid binary (ntloader) is compatible with BIOS and x86_64 UEFI. ntloader.i386 is compatible with BIOS and i386 UEFI. ntloader.arm64 is compatible with ARM64 UEFI.
It is recommended to use GRUB2 (>=2.12) and GRUB4DOS to boot NTloader.
Download
The source code is maintained in a git repository at https://github.com/grub4dos/ntloader.
You can download the latest version of the binary from GitHub Releases.
Getting Started
Extract ntloader and initrd.cpio onto the disk, and modify the bootloader menu to boot Windows from a FAT/NTFS/exFAT partition.
GRUB 2 (>= 2.12)
menuentry "Boot Windows NT6+ WIM" {
search -s --f /path/to/ntloader
search -s dev --f /path/to/winpe.wim
probe -s dev_uuid -u $dev
if [ "${grub_platform}" = "efi" ]; then
linux /path/to/ntloader uuid=${dev_uuid} wim=/path/to/winpe.wim
initrd /path/to/initrd.cpio
else
linux16 /ntloader uuid=${dev_uuid} wim=/path/to/winpe.wim
initrd16 /initrd.cpio
fi;
}
menuentry "Boot Windows NT6+ VHD/VHDx" {
search -s --f /path/to/ntloader
search -s dev --f /path/to/windows.vhd
probe -s dev_uuid -u $dev
if [ "${grub_platform}" = "efi" ]; then
linux /path/to/ntloader uuid=${dev_uuid} vhd=/path/to/windows.vhd
initrd /path/to/initrd.cpio
else
linux16 /ntloader uuid=${dev_uuid} vhd=/path/to/windows.vhd
initrd16 /initrd.cpio
fi;
}
menuentry "Boot Windows NT6+ on (hdx,y)" {
search -s --f /path/to/ntloader
probe -s dev_uuid -u (hdx,y)
if [ "${grub_platform}" = "efi" ]; then
linux /path/to/ntloader uuid=${dev_uuid}
initrd /path/to/initrd.cpio
else
linux16 /ntloader uuid=${dev_uuid}
initrd16 /initrd.cpio
fi;
}
GRUB 2 (< 2.12)
ntloader and initrd.cpio must be on the same ESP partition.
In UEFI, the chainloader command should be used to load ntloader and pass the path to initrd.cpio to it.
⚠️ GRUB 2 cannot properly handle command lines containing non-ASCII characters, so file names must not include non-ASCII characters.
menuentry "Boot Windows NT6+ WIM" {
search -s --f /path/to/ntloader
search -s dev --f /path/to/winpe.wim
probe -s dev_uuid -u $dev
if [ "${grub_platform}" = "efi" ]; then
chainloader /path/to/ntloader initrd=/path/to/initrd.cpio uuid=${dev_uuid} wim=/path/to/winpe.wim
else
linux16 /ntloader uuid=${dev_uuid} wim=/path/to/winpe.wim
initrd16 /initrd.cpio
fi;
}
GRUB4DOS / GRUB4EFI
Use the kernel command to load ntloader.
title Boot Windows NT6+ WIM
find --set-root /path/to/winpe.wim
uuid ()
find --set-root /path/to/ntloader
kernel /path/to/ntloader uuid=%?_UUID% wim=/path/to/winpe.wim
initrd /path/to/initrd.cpio
rEFInd
ntloader and initrd.cpio must be on the same ESP partition.
Use the fsuuid.exe tool included in the archive to obtain the UUID of the partition where the WIM/VHD is located.
For example, if the VHD path is D:\path\to\windows.vhd, run
fsuuid.exe D
to obtain the UUID of that partition, and replace PASTE_UUID_HERE in the menu below with the obtained UUID.
menuentry "Boot Windows NT6+ VHD/VHDx" {
loader /path/to/ntloader
initrd /path/to/initrd.cpio
options "uuid=PASTE_UUID_HERE vhd=/path/to/windows.vhd"
}
Kernel parameters
The maximum size of the command line without the terminating zero is 4096 bytes.
Boolean values can be expressed as yes and no, true and false, on and off, or 1 and 0.
Spaces in file paths should be replaced with :.
Slashes in file paths are automatically converted to backslashes.
uuid
uuid=XXXXXXXX
The filesystem UUID of the partition where the WIM/VHD is located.
initrd
initrd=/path/to/initrd.cpio
The path to the initrd file when booting with GRUB2 (<2.12) under UEFI.
Must be in the same ESP partition with ntloader.
wim
wim=/path/to/winpe.wim
The path to the WIM file.
vhd
vhd=/path/to/windows.vhd
The path to the VHD/VHDX file.
ram
ram=/path/to/ramos.vhd
The path to the VHD/VHDX file for RAMDISK boot.
file
file=/path/to/xxx.wim
file=/path/to/xxx.vhd
The path to the WIM/VHD/VHDX file. Bootloader will automatically detect the file type.
testmode
testmode=yes|no
Boolean value, enable or disable test signing mode. Default is no.
hires
hires=yes|no
Boolean value, enable or disable forced highest resolution.
Default is "yes" for WIM files; otherwise, default is "no".
detecthal
detecthal=yes|no
Boolean value, enable or disable HAL detection. Default is yes.
minint
minint=yes|no
Boolean value, enable or disable WINPE mode.
Default is yes for WIM files; otherwise, default is no.
novga
novga=yes|no
Boolean value, enable or disable the use of VGA modes entirely. Default is no.
novesa
novesa=yes|no
Boolean value, enable or disable the use of VESA modes entirely. Default is no.
altshell
altshell=yes|no
Boolean value, enable or disable the use of the alternative shell in safe mode. Default is no.
exportascd
exportascd=yes|no
Boolean value, enable or disable treating the RAMDISK as an ISO in RAMDISK boot mode. Default is no.
nx
nx=OptIn|OptOut|AlwaysOff|AlwaysOn
Set the Data Execution Prevention (DEP) policy. Default is OptIn.
pae
pae=Default|Enable|Disable
Enables or disables Physical Address Extension (PAE). Default is Default.
safemode
safemode=Minimal|Network|DsRepair
Boot into safe mode if this parameter is set.
gfxmode
gfxmode=1024x768|800x600|1024x600
Set the graphics resolution.
imgofs
imgofs=XXXXXX
Set the partition offset of the VHD/VHDX file in RAMDISK boot mode. Default is 65536.
loadopt
loadopt=XXXXXX
Set the load options for Windows.
For available options, see Boot Options.
winload
winload=XXXXXX
Set the path to winload.efi or winload.exe.
Default is /Windows/System32/Boot/winload.efi for WIM; otherwise, default is /Windows/System32/winload.efi.
Ntloader will automatically correct the file extension.
sysroot
sysroot=XXXXXX
Set the path to the system root directory. Default is /Windows.
Utilities
fsuuid
fsuuid is a tool to obtain the UUID of the partition where the WIM/VHD is located.
Useful for rEFInd and other bootloaders that do not support retrieving the filesystem UUID.
⚠️ Administrator privileges are required.
# Get the UUID by drive letter (Windows)
fsuuid.exe D
# Get the UUID by volume path (Windows)
fsuuid.exe \\?\Volume{XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}
# List all volume paths (Windows)
fsuuid.exe -l
# Get the UUID by device path (Linux)
fsuuid /dev/sdxY
mkinitrd
mkinitrd is a tool to create the initrd.cpio file.
You can use it to create a custom initrd file using bootmgr from other Windows versions.
You can also use cpio to create the initrd file.
# Create initrd.cpio with files from rootfs directory
mkinitrd.exe rootfs initrd.cpio
# Create initrd.cpio using linux utilities 'find' and 'cpio'
find * | cpio -o -H newc > ../initrd.cpio
bmtool
bmtool is a program for extracting bootmgr.exe from bootmgr.
bcd.bat
bcd.bat is a batch script to create the BCD file.
Do not edit it unless you know how NTloader works.
⚠️ Administrator privileges are required.
Compilation
gcc, gcc-mingw-w64 and gcc-aarch64-linux-gnu are required to compile NTloader.
Compile NTloader
# Build everything
make
# Build arm64 binary only
make ntloader.arm64
Compile fsuuid
make fsuuid
make fsuuid.exe
Compile bmtool
make bmtool
make bmtool.exe
Compile mkinitrd
make mkinitrd
make mkinitrd.exe
Build initrd.cpio
make initrd.cpio
Licence
NTloader is free, open-source software licensed under the GNU GPLv3.