Update information about boot override via IPMI

Add information about:
- 'none' boot source,
- one-time/persistent override,
- legacy/EFI selector,
- how to read current boot source override setting.

Signed-off-by: Konstantin Aladyshev <aladyshev22@gmail.com>
Change-Id: I3462ce5d52715b01b76f96ead9b94af5f95dc94e
diff --git a/IPMITOOL-cheatsheet.md b/IPMITOOL-cheatsheet.md
index 4daddf1..c8188d2 100644
--- a/IPMITOOL-cheatsheet.md
+++ b/IPMITOOL-cheatsheet.md
@@ -264,8 +264,9 @@
 
 Currently supported devices:
 
-| decive | function                                                    |
+| device | function                                                    |
 | :----: | ----------------------------------------------------------- |
+|  none  | do not change boot device                                   |
 |  pxe   | boot from pxe                                               |
 |  disk  | boot from BIOS default boot device                          |
 |  safe  | boot from BIOS default boot device,but requires a safe mode |
@@ -273,6 +274,38 @@
 | cdrom  | boot from the CD/DVD                                        |
 |  bios  | enter bios settings                                         |
 
+##
+
+If you want to make your override persistent over reboots use the `persistent` option:
+```
+$ ipmitool -C 17 -H "$BMC_IP" -I lanplus -U "$BMC_USER" -P "$BMC_PASSWD" chassis
+bootdev <device> options=persistent
+```
+
+##
+
+If the main host machine is based on the x86 CPU you need also pay attention to
+the legacy/EFI mode selector. By default IPMI overrides boot source with the legacy
+mode enabled. To set EFI mode use `efiboot` option:
+```
+$ ipmitool -C 17 -H "$BMC_IP" -I lanplus -U "$BMC_USER" -P "$BMC_PASSWD" chassis
+bootdev <device> options=efiboot
+```
+
+You can combine options with a help of `,`:
+```
+$ ipmitool -C 17 -H "$BMC_IP" -I lanplus -U "$BMC_USER" -P "$BMC_PASSWD" chassis
+bootdev <device> options=persistent,efiboot
+```
+
+##
+
+To read current boot source override setting:
+```
+$ ipmitool -C 17 -H "$BMC_IP" -I lanplus -U "$BMC_USER" -P "$BMC_PASSWD" chassis
+bootparam get 5
+```
+
 #### 7. Control panel logo light
 
 ```