How can i load the IDT?

[NunoLava1998]

I want to load the IDT. However, i can't find a page with steps on how to do it, and i can't find what order to do it in.

How can i load the Interrupt Descriptor Table?

github at https://github.com/NunoLava1998/DixiumOS

[iansjack]

http://wiki.osdev.org/IDT

[NunoLava1998]

http://wiki.osdev.org/IDT

I'm pretty sure i've read that a million times (and there is no text that shows how to do things). Not trying to offend.

[Octacone]

You load it with "lidt" instruction. If that was your question.

[NunoLava1998]

You load it with "lidt" instruction. If that was your question.

I meant something else. I know you have to load it with lidt.

I'm using C by the way. I'll use C++ when needed.

[glauxosdever]

Hi,


Since you are starting over, you should already know how to implement the features you implemented previously. Didn't you load the IDT previously? If so, why are you asking again the same question?

It's true that over time the community gets more experience as a whole, but:

• This applies to advanced topics;
• This applies over the course of years (don't let the New Year fool you, it's been just 12 days since you asked).

Also, the wiki should describe it clearly enough. If you however have issues understanding the wiki, you can try to ask.

Edit: Also, would you please remove the image from your signature (or at least replace it with a much smaller one)?


Regards,
glauxosdever

[alexfru]

I meant something else.

Then be constructive and tell us what it is that you don't understand or are doing (show your code) which isn't working. We have limited mind reading.

[NunoLava1998]

Hi,


Since you are starting over, you should already know how to implement the features you implemented previously. Didn't you load the IDT previously? If so, why are you asking again the same question?

It's true that over time the community gets more experience as a whole, but:

• This applies to advanced topics;
• This applies over the course of years (don't let the New Year fool you, it's been just 12 days since you asked).

Also, the wiki should describe it clearly enough. If you however have issues understanding the wiki, you can try to ask.

Edit: Also, would you please remove the image from your signature (or at least replace it with a much smaller one)?


Regards,
glauxosdever

I didn't really load it, just that QEMU probably was too nice and loaded it for me. And even then, it didn't work. I'm making everything (except the IDT, of course) with a pinch of salt now.

To anyone asking to remove the image:
okay

To anyone asking what i mean:

I mean about what to do when loading the IDT in a lot of detail, like what order to do functions, what to do, etc., the IDT page does not offer much information (and is confusing).
I am not asking for code.

[iansjack]

http://wiki.osdev.org/IDT

I'm pretty sure i've read that a million times (and there is no text that shows how to do things). Not trying to offend.

It describes the whole process of creating the IDT and loading it. What part don't you understand?

Or are you, perhaps, telling us that you don't understand the interrupt mechanism and how to write an interrupt handler?

[NunoLava1998]

http://wiki.osdev.org/IDT

I'm pretty sure i've read that a million times (and there is no text that shows how to do things). Not trying to offend.

It describes the whole process of creating the IDT and loading it. What part don't you understand?

Or are you, perhaps, telling us that you don't understand the interrupt mechanism and how to write an interrupt handler?

Uhh, not the latter part.

I don't understand a lot how the loading IDT process is like, etc.

I just need a (lot) more detail, which order to make, what to do.
I am not asking for code, by the way.

[alexfru]

If you know how interrupts work and you know that the IDT must be prepared and IDTR must be loaded with LIDT prior to using interrupts, what's left that you don't understand? Do you understand how GDT, GDTR and LGDT work? This is very similar. Selectors, offsets, segment/gate types, privilege levels, etc.

[iansjack]

OK. So you know how to write an interrupt handler. The wiki page tells you the format of the descriptors in the IDT and how to tell the processor where the table is located.

So what don't you understand?

[glauxosdever]

Hi,


If you don't understand something on the wiki, I'll try to rephrase it so it is more clear.


Regards,
glauxosdever

[NunoLava1998]

OK. So you know how to write an interrupt handler. The wiki page tells you the format of the descriptors in the IDT and how to tell the processor where the table is located.

So what don't you understand?

how to actually load the IDT (what do i need to prepare, what do i put in the lidt instruction, etc.)

If you know how interrupts work and you know that the IDT must be prepared and IDTR must be loaded with LIDT prior to using interrupts, what's left that you don't understand? Do you understand how GDT, GDTR and LGDT work? This is very similar. Selectors, offsets, segment/gate types, privilege levels, etc.

I don't understand the GDT too, however GRUB already loads this.

Hi,


If you don't understand something on the wiki, I'll try to rephrase it so it is more clear.


Regards,
glauxosdever

Okay. The IDT page doesn't offer much, so you can try to add more information.

[alexfru]

OK. So you know how to write an interrupt handler. The wiki page tells you the format of the descriptors in the IDT and how to tell the processor where the table is located.

So what don't you understand?

how to actually load the IDT (what do i need to prepare, what do i put in the lidt instruction, etc.)

Perhaps, you should follow your own advice?:

Read a bit more of your books and the wiki and you should be able to get it working.

Have you downloaded the CPU manual and located the descriptions of GDT, GDTR, LGDT? Ditto for IDT, IDTR, LIDT?