IMacs can boot Linux or Windows from usb stick

Question

iMacs 21' can boot Linux or Windows from usb stick? from Firewire 400 or 800 hdd/ssd? from USB HDD/SSD?
May boot fromCD/DVD/DVDDL in internal DVD DRIVE, too?
Exist Blu-ray drives able connect on Thunderbolt slot on iMac 21'?

Answer 1

Here is the memo of the steps I followed. Hope this helps.
<Create VHD image in temp folder at local drive>
diskpart
create vdisk file=C:\Temp\Win2go.vhd maximum=20480 type=fixed
select vdisk file=C:\Temp\Win2go.vhd
attach vdisk
exit
<Create partition in VHD, format in NTFS and assign drive letter "O">
diskpart
list disk
select disk n （n is a number of VHD）
clean
create partition primary
format fs=ntfs quick override
assign letter=o
active
attribute volume set NODEFAULTDRIVELETTER
exit
<Execute "DISM" utility in Windows DVD and extract installer image to VHD>
G:\sources\dism /apply-image /imagefile:G:\sources\install.wim /index:1 /applydir:O:\
** "G" is drive letter for Windows DVD
** "O" is drive letter for VHD partition
<Write boot program into VHD>
O:\windows\system32\bcdboot O:\windows /f ALL /s O:
** "O" is drive letter for VHD partition
<Detach VHD>
diskpart
select vdisk file=C:\Temp\Win2go.vhd
detach vdisk
exit
<Format USB thumb drive in NTFS>
diskpart
list disk
select disk n （n is a number of USB thumb drive）
clean
create partition primary
format fs=ntfs quick override
active
exit
** "E" is drive letter for USB thumb drive
<Write loader into boot sector>
G:\boot\bootsect /nt60 E:
** "G" is drive letter for Windows DVD
** "E" is drive letter for USB thumb drive
<Copy VHD file to USB thumb drive and mount>
copy C:\Temp\Win2go.vhd E:\
diskpart
select vdisk file=E:\Win2go.vhd
attach vdisk
exit
<Write boot info into USB thumb drive>
F:\Windows\system32\bcdboot F:\Windows /s E: /f ALL /v
** "E" is drive letter for USB thumb drive
** "F" is drive letter for VHD partition on USB thumb drive