| hardware interrupt arrival ↓ |
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idtIRQ() (idtIRQ.S)
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CLI (hard)
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RTAI mounted? |
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No | Yes | |||||||||||||||||||||||||||
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•if (IP7) jalr (rthal.mips_timer_interrupt)
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→ | mips_timer_interrupt() (normal kernel) •mask & ack irq •sti() •do_timer(regs) •update compare •cli() •re-enable irq •return 1 |
•dispatch_mips_timer_interrupt() (in rtai) •mask & ack irq •save regs [IRQ_TIMER] •if global handler { call it; } •else {assert pending irq} •hard_sti() •if(in_rt) { linux_sti(); return 1;}
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| •else jalr (rthal.idt_interrupt) | → |
idt_interrupt() (normal kernel dispatch) •mask & ack irq •sti() •run action handlers •cli() •re-enable irq •return 1 (always) |
dispatch_idt_interrupt() (in rtai) •mask & ack irq •save regs [IRQ_GENERAL] •assert pending irq •hard_sti() •if(in_rt) { linux_sti(); return 1;} •else return 0; |
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| •if(v0) jr (ret_from_irq) | ← | ||||||||||||||||||||||||||||