kernel debugging without a serial port ?

Submitted by Fabien D on Sun, 02/01/2009 - 11:50.

Modern computers usually don't have a serial port.
Reminder : the jnode kernel debugger uses the rs232 port, which means that a serial port is needed on the computer.

For instance, I am trying to debug jnode on the eeepc computer but it's very hard since it doesn't have a serial port and nothing else than a single character is displayed on the screen.

The only possible solution that I see for the general case is to install a pci card that provide a serial port. But for the particular case of the eeePC, it's not possible (no pci slot available afaik) since there is only USB ports, 1 ethernet port and an SD/SDHC slot ...

Any idea for the particular case of the eeePC ?

‹ Building JNode CD-ROM image Exception Exception: building CD-ROM image[JNode-OS] ›

USB to serial port adapter?

Submitted by Stephen Crawley on Sun, 02/01/2009 - 13:48.

A Google search on "USB serial port" gives hits for several companies that sell USB to serial adapters. However, this won't immediately solve your problem. For a start, the JNode's assembler core does not understand how to configure and use a USB device.

I know such adapters exist

Submitted by Fabien D on Sun, 02/01/2009 - 15:20.

I know such adapters exist but I have been told they are only emulators of rs232 protocol, which might mean it won't even work. Moreover they need a driver (unlike for the use of serial line) + the generic support for USB.
So, I am afraid it's not a solution.

Other alternatives might be usb-usb or ethernet-ethernet links but I think they both need a driver on jnode side and so they are too high level for boot time debugging.

Fabien

my blog : en français, in english or both