For example, a process waiting for disk I/O to complete will sleep on the address of the buffer header corresponding to the data being transferred. When the interrupt routine for the disk driver notes that the transfer is complete, it calls wakeup on the buffer header. The interrupt uses the kernel stack for whate...
I'm trying to learn more about how systems really work underneath all the pretty graphics on top. So I'm currently playing with memory in the 512bytes that the BIOS loads on startup, can't really call it a bootloader at the moment I guess. Anyway, I'm replacing an interrupt vector but having issues with it. After replacing interupt 09h (...
This question is from the interrupt handling topic. Suppose an interrupt is being serviced. What happens if another interrupt is raised even before the first interrupt action is completed? ...
I have a java program which creates a lock file to ensure that no other executions run at the same time as it. If the program runs it creates the file, and upon exit, either successful or via an exception, the file is removed. But if the user hits Ctrl+C, closes the terminal, or in some other way interrupts execution, the file is not d...
Are Interrupts assigned to a fixed CPU (always handled by the same CPU)? To put my question in context: From: http://msdn.microsoft.com/en-us/library/ms795060.aspx The spin lock that protects the shared area has an IRQL equal to the DIRQL at which the device interrupts. As long as the critical-section routine holds the spin lock and a...
Maybe the question should be, are external interrupts even vectored on the PowerPC at all? I've been looking at http://www.ibm.com/developerworks/eserver/library/es-archguide-v2.html, 'book 3', trying to figure out how the processor locates the appropriate interrupt service routine in response to an external interrupt. It seems to sugg...
From: http://software.intel.com/en-us/articles/introduction-to-pc-architecture/ Exception number 10h corresponds to a "Floating Point Error" but software interrupt 10h also corresponds to "Video support" BIOS interrupts (both in real mode). What am I missing? ...
Do CPUs (specifically powerpc) allow an interrupt handler to be installed for IPIs (inter processor interrupts) ? The MPIC I am using supports 4 IPIs per core and it has registers for setting the vector and priority of these IPIs, but where should I install the interrupt handler ? The CPU core has IVORs (Interrupt Vector Offset Registers...
I am running a thread whose main action is to call on a proxy using a blocking function , and wait for it to give it something. I've used the known pattern of a volatile boolean and the Interruption , but I'm not sure it will work: When I tried to add a catch block for "InterruptedException" , I get the error "Unreachable catch block ...
I can detect that the iPhone went to sleep and came back from sleep, by using the applicationWillResignActive and applicationDidBecomeActive. But how do I find out what kind of interrupt it was. I am making an audio player application, and need to keep the audio playing when the iPhone goes to sleep (which I know how to do). But I need t...
I wanted to know when the processor get's interrupted and an ISR (interrupt service routine) is executed, is that executed in the context of the thread that was interrupted to handle this interrupt or is it executed in its own thread and then goes back to where it left of in the original thread? So a context switch actually occurs when ...
Hi to all Could we use the Int 13h (direct disk read/write) in Windows operating systems or does the windows protected mode not allow us, and if so is there a work round? Thanks in advance. ...
I have the following card and cannot get interupts working. I may not be understanding how they're supposed to work correctly... I don't do this type of programming very often. From the looks of it though, it should be able to generate an interrupt when something comes in on one of the IO ports, right? We've got it hooked up to a bunch ...
In my MIPS32 exception handler, I want to determine whether the exception was caused by a I/O interrupt. The Cause register bits 2-6 inclusive has to be checked. What's the MIPS assembly code to determine this? ...
Hi all, My AVAudioRecorderDelegate Interruptions methods doesn't get called. I set the delegate. What might be the issue here? tnx ...
I am an old hand with hardware and device drivers and used much earlier Linux versions for hardware control. I am recently back in the game of Linux and device control using embedded processing and have discovered a lot has changed in the Linux world (for the better). However, I am struggling with a hardware control issue involving a ver...
I am posting the following piece of code, the basic aim of this code is, when i set the trap flag to 1 then after that i am printing a character z on the screen, now as trap flag is set, the program should execute one instruction and trap, I have written a simple trap ISR in which i have an infinite loop, this infinite loop will be broke...
I'm learning the Work queues to code bottom halves in the linux kernel. I wonder: if the interrupt handler is executed two times (thus calling schedule_work two times), does the work queue handler be called once or twice? ...
When entering an inteerupt handler, we first "disable interrupts" on that cpu(using something like the cli instruction on x86). During the time that interrupts are disabled, assume say the user pressed the letter 'a' on the keyboard that would usually cause an interrupt. But since interrupts are disabled, does that mean that: 1. the inte...
Hi, I am working on an iphone application in which user need to login to visit some restricted area for this I am using web services. My problem start when user login successfully but if a call interrupt the app then after call attend the session in app get lost i.e user get logout. How can i maintain a user login/session even a call int...