> > I am spending this weekend appreciating and trying to understand kdb. I have > integrated it within the 2.4.7 kernel I am working with and can make the > trivial change and expect success. The next step is I am trying to > understand a few things and any suggestions of comments would be greatly > appreciated: > > 1) I can get it to work on a keyboard/vga, but cannot seem to be able to > send the break on the serial port to get its attention. I would like to > understand what is going on.
It is likely that this is due to the fact that the serial port hasn't been opened yet. You need to make sure that something (like mingetty or getty) is running on the serial port before trying to get KDB's attention (this is because the interrupt handler won't be attached to the serial port until some program opens the port). This is one of the main limitations of the serial port. You can work around this by specifying the appropriate keyword on the lilo commandline to induce kdb to stop in early system initialization. You can then set breakpoints, etc. from the serial port. Otherwise, you'll have to wait for the system to come up. > 2) I would like to be able to change kdb to read from and write to an IO > port address (essentially and IODR version of MDR, or a IOM version of MM). > I am concentrating on making another linkage from kdbmain to a modified > version of say kdba_io.c. Reuse, reuse, reuse. I would look at extending the m-series commands (e.g. mdio and mmio). I actually did this once, but the work got misplaced when I left SGI. scott > > Charles Krinke >
