interrupt

In the function declaration int request_irq(unsigned int irq, irqreturn_t (*handler)(int, void *, struct pt_regs *), unsigned long irqflags, const char *devname, void *dev_id); Is dev_id an 'in' parameter or an 'out' parameter ? Where do we get this number from ? Dev_id is an input argument and must be globally unique. Normally the address of the device data structure is used as the Dev_id . It has value NULL if the interrupt line is NOT shared. It holds relevance only when the interrupt line is being shared. When it is shared, this parameter uniquely identifies the interrupt handler on the

I'm building a programm to ask multiplication and I want to set up a timer to force the person to give its answer in a given time : if the person answers before the end of the timer : go next multiplication if the timer reach its end, stop waiting user input : go next multiplication For the moment, case 1 can be done, but 2 not, I was thinking about a way to return; from the method within like a Thread or something, bu I don't know how So I'm facing a problem, if a Scanner is open, waiting for input, how to stop it ? I've tried putting it in a Thread and interrupt() it or using boolean as

i'm having hard time trying to understand how interrupts work. the code below initialize the Programmable Interrupt Controller #define PIC0_CTRL 0x20 /* Master PIC control register address. */ #define PIC0_DATA 0x21 /* Master PIC data register address. */ /* Mask all interrupts*/ outb (PIC0_DATA, 0xff); /* Initialize master. */ outb (PIC0_CTRL, 0x11); /* ICW1: single mode, edge triggered, expect ICW4. */ outb (PIC0_DATA, 0x20); /* ICW2: line IR0...7 -> irq 0x20...0x27. */ outb (PIC0_DATA, 0x04); /* ICW3: slave PIC on line IR2. */ outb (PIC0_DATA, 0x01); /* ICW4: 8086 mode, normal EOI, non

I'd have some code that needs to be run as the result of a particular interrupt going off. I don't want to execute it in the context of the interrupt itself but I also don't want it to execute in thread mode. I would like to run it at a priority that's lower than the high level interrupt that precipitated its running but also a priority that higher than thread level (and some other interrupts as well). I think I need to use one of the other interrupt handlers. Which ones are the best to use and what the best way to invoke them? At the moment I'm planning on just using the interrupt handlers

I'm working on a project that has tight boot time requirements. The targeted architecture is an IA-32 based processor running in 32 bit protected mode. One of the areas identified that can be improved is that the current system dynamically initializes the processor's IDT (interrupt descriptor table). Since we don't have any plug-and-play devices and the system is relatively static, I want to be able to use a statically built IDT. However, this proving to be troublesome for the IA-32 arch since the 8 byte interrupt gate descriptors splits the ISR address. The low 16 bits of the ISR appear in

I'm working on a Java application that utilises shutdown hooks in order to clean up on termination/interruption of the program, but I've noticed that Cygwin's implementation of CTRL-C doesn't seem to trigger the shutdown hooks. On the surface it appears to have interrupted the process, relinquishing control back to the command line, however the process' shutdown hooks are not triggered at all so cleanup does not occur. In cmd they get caught, but due to various constraints I need to somehow get them working in Cygwin. Is there any way to fire a SIGINT at a running process through Cygwin at all

I am on linux kernel 2.6.32. I am facing an issue in which one of the two ISR (serial and ethernet) are taking more time (hundreds of microseconds) on several occasion/under some scenarios which I don't know. I would like to get the time difference every time the ISR executes. What would be the best way (least expensive in terms of overhead involved). I don't see ARM architecture has some TSC register (read_tsc api) which would give me direct access to time as it offers on some other architecture. So Idea is 1) The moment ISR is invoked measure time 2) the moment ISR is complete measure the