The eighth parameter "Diagnostics" can be used to run comprehensive diagnostics over the hardware and the environment in which it is being used. As it performs the various checks, those checks and the results are display on the screen.

Unfortunately, there are a lot more diagnostic information than space on the screen and it simply flashes past, pausing only to ask whether a particular check should be run. Typing "x" will bypass the check. However you do get a summary at the end of the checks performed and their status, which can still be useful.

Diagnostic Output
A complete diagnostic listing as shown here, can be obtained by setting the stdout environment variable to "serial" and connecting a null modem cable to another computer running a terminal program.

*** Begin Memory Test *** Pattern 005A005A  Writing...          Reading... Memory test completed! *** Begin Mouse Test *** Detected PS/2 Mouse Port! *** Begin KBD Test *** Keyboard test 0 passed. Keyboard test 1 passed. Keyboard test 2 passed. Keyboard test 3 passed. Keyboard test 4 passed. Keyboard test 5 passed. Keyboard test 6 passed. Keyboard test 7 passed. Keyboard test 8 passed. Keyboard test 9 passed. *** Begin RTC Test *** RTC test completed! *** PCI Test *** Scanning PCI devices on bus 0 BusDevFun  VendorId   DeviceId   Device Class       Sub-Class _____________________________________________________________ 00.00.00   0x10cc     0x0660     Bridge device           0x00 00.01.00   0x10cc     0x0661     Bridge device           0x04 00.06.00   0x10b7     0x9200     Network controller      0x00 00.07.00   0x1106     0x0686     Bridge device           0x01 00.07.01   0x1106     0x0571     Mass storage controller 0x01 00.07.02   0x1106     0x3038     Serial bus controller   0x03 00.07.03   0x1106     0x3038     Serial bus controller   0x03 00.07.04   0x1106     0x3057     Build before PCI Rev2.0 0x00 00.07.05   0x1106     0x3058     Multimedia device       0x01 00.07.06   0x1106     0x3068     Simple comm. controller 0x80 00.09.00   0x1102     0x0002     Multimedia device       0x01 00.09.01   0x1102     0x7002     Input device            0x80 PCI test completed! *** Begin IDE Test *** Write test is disabled.   read succes -> 1 Write test is disabled.   read succes -> 1 Write test is disabled.   read succes -> 1 Write test is disabled.   read succes -> 1 Write test is disabled.   read succes -> 1 IDE test completed! *** Begin USB Test *** starting USB... USB:   scanning bus for devices... 1 USB Devices found Device Information:   1  Hub (12MBit/s, 0mA)      UHCI Root Hub 1: Hub,  USB Revision 1.0  - UHCI Root Hub  - Class: Hub  - PacketSize: 8 Configurations: 1  - Vendor: 0x0000 Product 0x0000 Version 0.0    Configuration: 1    - Interfaces: 1 Self Powered 0mA      Interface: 0      - Alternate Settings 0, Endpoints: 1      - Class Hub      - Endpoint 1 In Interrupt MaxPacket 8 Interval 255ms Scan for storage device:        scanning bus for storage devices... No USB storage device found. *** Begin Ethernet Test *** This Ethernet test requires a loopback connector with the following pins connected: 1 <--> 3    ( TX+ <--> RX+ ) 2 <--> 6    ( TX- <--> RX- ) If the required connector is not available, please press 'x' now; otherwise, press any other key to continue Eth test skipped! *** Begin Parallel Port test *** This LPT test requires a loopback connector with the following pins connected:  1 <--> 13  ( -Strobe   <--> +Select In )  2 <--> 15  ( +Data0    <--> -Error ) 10 <--> 16  ( -ACK      <--> -Initialize ) 11 <--> 17  ( +Busy     <--> -Select ) 12 <--> 14  ( +PaperEnd <--> -AutoFeed ) If the required connector is not available, please press 'x' now; otherwise, press any other key to continue Parallel Port test skipped *** Serial Test ***This Serial test requires loopback connector on COM1 with the following pins connected: 1, 4, 6, 9  (CD, DTR, DSR, RI) 2, 3        (RD, TD) 7, 8        (RTS, CTS) If the required connector is not available, please press 'x' now; otherwise, press any other key to continue This Serial test requires loopback connector on COM2 with the following pins connected: 1, 4, 6, 9  (CD, DTR, DSR, RI) 2, 3        (RD, TD) 7, 8        (RTS, CTS) If the required connector is not available, please press 'x' now; otherwise, press any other key to continue Serial test skipped *** Diagnostics Summary *** Memory test passed! PS/2 Mouse port test passed! Keyboard test passed! RTC test passed! PCI test passed! IDE test passed! USB test passed! *** Diagnostics Complete ***

To return to the U-Boot Preferences Menu press the Esc key.