I Can't Get Interrupts Working: Difference between revisions
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For this test, you need to call the interrupt yourself, by software. Don't try to get [[IRQ]] handled right from the start before you're sure your IDT setup is correct. You need to have: |
For this test, you need to call the interrupt yourself, by software. Don't try to get [[IRQ]] handled right from the start before you're sure your IDT setup is correct. You need to have: |
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* Your IDT loaded and filled properly. |
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* Your IDT's ''linear'' address loaded in a structure together with the table's size (in bytes, IIRC). Be especially cautious if you have a [[Higher Half Kernel]] design or did not set up [[Identity Paging|identity paging]]. |
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* A valid Code selector and offset in the [[Descriptors|descriptor]], proper type, etc. |
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* A handling code at the defined offset. |
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'' see [[#Assembly_Examples|test code]] below '' |
'' see [[#Assembly_Examples|test code]] below '' |
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=== My Handler doesn't get called (C)?! === |
=== My Handler doesn't get called (C)?! === |
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If you |
If you are programming the IDT setup in C, make sure the IDTR structure has been correctly understood by your compiler. As Intel's 6 bytes structures infringe most compiler's packing rules, you'll need to use either ''bitfields'' or ''packing pragmas''. Use <tt>sizeof()</tt> and <tt>OFFSETOF()</tt> macros to make sure the expected definition is used (a runtime test would be fine) |
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=== My handler is called but it doesn't return !? === |
=== My handler is called but it doesn't return !? === |
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