BIOS FAQ

 

What are the different ways to boot an OS on the SBC?


How can I enter CMOS setup, what can I do?


How do I used the BIOS debugger? What can it do?

There are 3 ways to enter the BIOS debugger:

  1. From CMOS setup select Integrated BIOS debugger.
  2. From DOS-ROM command prompt type int3
  3. From within any DOS executable make the assembly language call "int 3"

The BIOS debugger allows you to:

  • display and edit memory locations.
  • display and edit I/O locations
  • single step through code
  • set breakpoints
  • view BIOSDATA, RTC and other system regions
  • change the I/O console
  • more ...

See the BIOS user's manual for a complete guide to the BIOS debugger


How can I change the speed of the console, how can I boot faster?


How do I "Format Integrated Flash Disk" from the BIOS setup screen?


How do I run "manufacturing mode" and what can it do?

Manufacturing mode allows you to map the Flash-drive (A:) on the SBC as the next available hard drive on a host system using an RS232 communications link. The device driver will only work with a host system that is DOS 6.22 or equivalent.

To install the device driver in the host system:

  1. Download the DOS device driver mfgdrv.sys to the host system.
  2. Edit the config.sys file to run the driver, on my test system it looks like this:
    device=c:\biosutil\mfgdrv.sys /unit=0 /baud=38k /port=com1
    (See user's manual for details, available from the main SBC page.)
  3. Reboot the host system.

To put the SBC in manufacturing mode:

Install jumper JP1 and reboot

OR

Hit Ctrl-C during boot up and select "Start RS232 Manufacturing Link".

The Flash-drive should now be available as the next available hard-drive letter on the host system, on my test system it is the D: drive. You can copy/delete/move just as if the drive were local, although at reduced transfer rates due to the serial link. The mfgdrv.sys driver maps a drive letter on the host machine to the SBC's physical drive exported by INT13, most DOS programs should work fine. If you need to format the SBC's drive use the version of format for DOS-ROM available on our support page.


What does "invalid media" error mean?

The ROM-DOS format of the Flash disk is corrupt. The BIOS and DOS sectors of the Flash chip are likely to be intact, or the system wouldn't have functioned well enough to display this message. If the problem is due to a hardware error, the unit must be sent back to Technologic Systems for repair. You may want to try formatting the Flash disk if case the problem is due to an application corrupting the FAT.


What does LED D2 indicate during the boot process?

The hardware turns on LED D2 by default when power is applied. The LED is turned off by the BIOS code early in the boot process, here is the boot sequence in relation to the LED state:

  1. Power applied - LED on by default.
  2. BIOS code turns LED off early in boot process, then initializes the CPU.
  3. BIOS code turns LED on then copies BIOS and DOS from Flash to RAM.
  4. BIOS code turns LED off then finishes the boot process.

A flashing LED indicates a critical hardware error, the system cannot boot.

The LED is available for user diagnostics after boot up is complete


How does the redirected console work?

The redirected console is supported by the BIOS. Any data sent to stdio (normally video) will be redirected to the selected COM port (COM2 by default). And data received from the COM port is treated as input from stdin (normally keyboard). You can use printf() and getch() under C with the redirected console just like with keyboard/video. Some of the standard BIOS calls for video and keyboard will work with the console redirected, the BIOS will handle the translation. See the BIOS manual for more information.