Bochs cmos code#

I do not have an LDT and I read it wasn't mandatory!?'. Go back to your chip's data sheet and double-check that your sizes are correct. Reading a byte from port 0x1234 is usually not the same thing as reading a 32-bit value. Your page tables do not point to the correct parts of memoryīochs performs some rather paranoid checks on I/O operand size.You have not loaded an IDT, or the IDT is corrupt interrupt(): gate descriptor is not valid sys seg.Some common messages that might be displayed: In several cases, there are other error messages prior to this one which can provide more details in the error.

Push 0xf001 pop ds 0xf001 is no valid segment, mov ax, ~ let's see if we get the GPF Check your exception works with 'illegal' asm instructions like idiv 0, or

Sometimes (but less likely), it can also be due to a severe bug in your exception handler code. This is probably due to a bad IDT register content, or a bad IDT descriptor.

The CPU didn't manage to invoke an exception handler and would normally triple fault.

Bochs cmos code#

Make your code more clean, test pointers before you follow them, initialize every pointer (especially those who are on the stack) and enable *-Wall* in GCC. This means you either followed a NULL (or uninitialized) pointer, or you damaged the return address of your stack frame. You sent your code pointer (EIP) to some uninitialized memory area.

2 Differences between Bochs and real hardwareįrequent error messages Running in Bogus Memory.