[PATCH] doc: add a section on flashing images

[Henning Schild <henning.schild@siemens.com>]

Signed-off-by: Henning Schild <henning.schild@siemens.com>
---
 doc/user_manual.md | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/doc/user_manual.md b/doc/user_manual.md
index 70cf20a74828..e1d7166911e2 100644
--- a/doc/user_manual.md
+++ b/doc/user_manual.md
@@ -232,6 +232,14 @@ qemu-system-x86_64 -m 256M -nographic -bios edk2/Build/OvmfX64/RELEASE_*/FV/OVMF
 qemu-system-i386 -m 256M -nographic -hda tmp/deploy/images/qemui386/isar-image-base-debian-buster-qemui386.wic.img
 ```
 
+#### Flashing such images to a physical device
+
+wic images can be flashed in multiple ways. The most generic and easy way is probably with [ etcher ](https://etcher.io). That works on many operating systems and is relatively easy to use. On top it can decompress images on the fly, should they be compressed. It also offers some sort of protection so you do not write to the wrong device and maybe break your machine.
+
+If you have a unix shell there are other ways. Make sure to always double check the target device, those tools will not warn if you choose the wrong target.
+
+`dd` is the most generic option, available pretty much everywhere. For large images that contain a lot of empty space `dd` might be a little slow because it writes all that empty space. In that case `bmaptool` can be used instead.
+
 ### Generate container image with root filesystem
 
 A runnable container image is generated if you set IMAGE_TYPE to 
-- 
2.26.3