USB legacy boot order inconsistent - System x3650 M4 (7915)

Resolving The Problem

Source

RETAIN tip: H211530

Symptom

This issue can happen on other IBM System x M4 systems, because the issue is a design limitation in the UEFI. The IBM System x3650 M4 is used as an example.

There is a two-part issue with multiple Universal Serial Bus (USB) keys in legacy boot with the IBM System x3650 M4, type 7915.

The first part of the issue is that there is a limitation that the two USB keys on the system cannot be the same. Due to the legacy boot limitation, two keys with the same vendor ID or device ID confuse the system and only one of them will start. On IBM System x3650 M4, the order of USB ports is

Rear USB Port > Internal Hypervisor Port > Front Panel Port.

The second part of the issue is that the actual start order is inconsistent with the Start Order setting in the F1 Setup menu.

Here is an example of the second part of the issue:

1. Two USB keys of different vendors "A" and "B" are plugged into 'USB1: USB Port Hypervisor' and 'USB2: Front Panel Top' respectively.
   
2. The Start Order in F1 Setup is set to:
   1. PXE Network
   2. USB1
   3. USB2
3. The system starts to USB Key B after Preboot eXecution Environment (PXE) fails.
   

The expected behavior is starting to USB Key A after PXE fails.

Affected configurations

The system can be any of the following IBM servers:

• System x3650 M4, type 7915, any model
• This symptom can happen on other IBM System x M4 systems.

This tip is not software specific.

This tip is not option specific.

The following system BIOS/uEFI levels are affected:

• IMA VVEV24UUS
• IMA VVE127MUS
  

Workaround

There is no fix planned for IBM System x3650 M4, but a fix is planned for the next generation of systems in the next major release of Unified Extensible Firmware Interface (UEFI) Basic Input/Output System (BIOS).

The first part of the issue can be prevented by using USB keys from different vendors. This is a limitation in the design, and currently there is no other workaround for this.

The second part of the issue can be prevented either by removing the selection 'PXE Network' from the start order or by changing some start settings.

Here is how to remove the 'PXE Network' boot option:

1. Enter the F1 Setup menu at Power-On Self-Test (POST).
2. Select Boot Manager and select Delete Boot Options.
3. Select the PXE Network boot option by using the space key.
4. Select Commit Changes.

If PXE Network boot is required on the system, the following two changes need to be made. Each change is described in detail.

1. Disable Optimized Start
2. Set only the first USB device with a Physical Presence start option to start in the Start Order.

Disable Optimized Start

To disable Optimized Start, follow this procedure:

1. Enter the F1 Setup menu at Power-On Self-Test (POST).
2. Select Boot Manager and scroll down to select Boot Modes.
3. Select Optimized Boot, change the value to Disabled.
4. Exit to the main page of Setup, select Save Settings.
5. Restart the system.

Use the Physical Presence start option

To use the Physical Presence start option, or a platform-specific start option, follow this procedure:

1. Plug the USB key that users want to start first into the port.
2. Enter the F1 Setup menu at Power-On Self-Test (POST).
3. Select Boot Manager, then select Add Boot Options.
4. Select Physically Present Device, then select the plugged USB devices.
5. Exit to the Boot Manager page, then select Delete Boot Options.
6. Select all other USB start options by using the space key, then select Commit Changes.
7. Exit to the Boot Manager page and select Change Boot Order.
8. Change the device start order to the sequence desired.
9. Restart the system.

Additional information

This issue can happen on other IBM System x M4 systems, because this issue is a design limitation in the UEFI.