Keyboard IRQ hits only once, PIT works fine.
Posted: Sun Sep 21, 2014 7:35 am
Hello,
This is my another attempt to write an OS from scratch. I always stop at writing the IRQ handler. The problem is that the keyboard IRQ hits only once.
I've always read http://wiki.osdev.org/I_Cant_Get_Interrupts_Working. The conclusion was that I didn't send the End Of Interrupt signal to the PIC(s). But it's not so - I wrote a code at the end of the IRQ handler that sends EOI to the PIC(s) and it was steel not working.
Today, when I again tried to write the IRQ handler, I tried to don't disabling all the IRQs (except keyboard). The result was printing the "Interrupt was occurred." string on the screen every <1 second (the PIT's work) [my IRQ handler prints that on every IRQ].
So, I don't know why the PIT IRQ hits every <1 second, but keyboard IRQ only once? (I press a key every second at least.)
You can see the source code at https://github.com/ExeTwezz/Basic_OS:
This is my another attempt to write an OS from scratch. I always stop at writing the IRQ handler. The problem is that the keyboard IRQ hits only once.
I've always read http://wiki.osdev.org/I_Cant_Get_Interrupts_Working. The conclusion was that I didn't send the End Of Interrupt signal to the PIC(s). But it's not so - I wrote a code at the end of the IRQ handler that sends EOI to the PIC(s) and it was steel not working.
Today, when I again tried to write the IRQ handler, I tried to don't disabling all the IRQs (except keyboard). The result was printing the "Interrupt was occurred." string on the screen every <1 second (the PIT's work) [my IRQ handler prints that on every IRQ].
So, I don't know why the PIT IRQ hits every <1 second, but keyboard IRQ only once? (I press a key every second at least.)
You can see the source code at https://github.com/ExeTwezz/Basic_OS:
- kernel/src/idt.c : has IRQ handler.
kernel/src/isrs.asm : code in Assembly that calls the IRQ handler.
