On Sun, 18 Feb 2018, Fredrik Noring wrote: > > Substitute `mips:5900' for `mips:isa32r2' to get R5900 disassembly. If > > you want to see raw machine code too, use `disassemble -r', but watch out > > for the syntax, which is different. As you can see the trailing NOPs > > required are already there. :) > > Due to trailing zeroes, I suppose. :) It's no coincidence and we use it to our advantage that an all-zeros pattern is the canonical NOP instruction encoding. > > A handler for SIO is needed if SIOInt can be asserted without kernel > > control by PS/2 hardware. Otherwise handlers will only be needed once the > > kernel has means to enable the respective exceptions. > > Serial I/O requires soldering for the PS2. Jürgen Urban, Rick Gaiser, and > others have it and they can more easily debug the early boot stages. The > proposed PS2 serial driver uses a 20 ms timer and polling instead of SIOInt: > > https://github.com/frno7/linux/blob/ps2-v4.15-n7/drivers/tty/serial/ps2-uart.c So it looks like a random SIOInt is not supposed to happen and therefore I think a handler is not needed for the initial submission of the port if at all. > I don't have a serial port. My setup consists of ssh over a wireless RT3070* > USB device. Obviously a great number of things could potentially fail in > that chain but it is surprisingly reliable. :) This has prompted me to look at what PS2 hardware provides and it indeed seems lacking in basic I/O connectivity. What could one expect from a game console anyway? Do you use the netconsole then too? Using a USB serial port adapter would be an alternative, although not a very powerful one either, because you need to have many parts of the OS initialised before you can get to such a port. Maciej
