ioctl (Input Output ConTroL) is a system call for device-specific I/O operations and other operations which cannot be expressed by regular system calls and it provides an interface through which an application can communicate directly with a device driver(or any other global kernel space variables). Applications can use the standard control codes or device-specific control codes to perform direct input and output operations.
Questions tagged [ioctl]
691 questions
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Can`t open device by CreateFile, ERROR_INVALID_FUNCTION
I try to open device object and send request to my driver by CreateFile and DeviceIoControl, but CreateFile fails with ERROR_INVALID_FUNCTION, also if I try to open device in WinObj - I get the same error, so how to solve this and what is it…
Andrii Matiiash
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2 answers
How to get base_baud frequency of a com-port in windows
Is there a windows call to get the baud base frequency, like this one in linux.
struct serial_struct ser;
ioctl(com, TIOCGSERIAL, &ser);
base = ser.baud_base;
Björn
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IRP_MJ_DEVICE_CONTROL — how to?
Coding a app using serial port, when debugging, I have been compelled to work with low level (link control) protocol.
And here my problems begun.
Sniffer gives me values:
IOCTL_SERIAL_SET_BAUD_RATE 80 25 00 00 means baud rate 9600. Well, 00 c2 01 00…
Олег Сидоров
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Why does copying a struct from user space fails in an ioctl command?
I'm developing a device driver and need to make use of IOCTL. Unfortunately I cannot copy a struct from user space. Here is the code (simplified, error handling removed):
Structure
struct secvault_createoptions {
int secvaultId;
long…
Oliver Hanappi
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Windows Storage Management API - VDS (Virtual Disk Service) Uninstall Disk Equivalent method
Since VDS is being deprecated and the Windows Storage Management API is replacing it - are there any WMI, IOCTL, DeviceIoControl or Windows Storage Management API methods that are equivalent to the VDS method "UninstallDisks"?
I'm not able to find…
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how to deal with "hwclock: ioctl(RTC_RD_TIME) to /dev/rtc to read the time failed: Invalid argument"
I am trying to set the system time using real time clock interfaced with my raspberry pi.I am getting the above mentioned error
suraj
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'ioctl' signature for device mapper
The question may seem naive, but I'm new to kernel/driver programming. I created a device mapper over a block device, which is working fine. It's constructor/destructor and map methods are called.
Now, I'm trying to write an ioctl for this mapper.…
user2255299
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IOCTL Driver SystemBuffer always NULL
I have a simple struct which I would like to pass to my driver. Here is the struct:
typedef struct readStruct
{
...
} ReadStruct, *pRreadStruct;
Here is my usermode application:
DWORD dwReturn;
readStruct reader{ ... };
WriteFile(hDriver,…
Jussi Hietanen
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Process IDs are the same in User mode and Kernel mode
I was shocked that I got the same PID between User mode and Kernel mode in an IOCTL request from my application to my kernel driver(WDM) via DeviceIoControl() Win32 API.
As far as I know, drivers have its own PID in kernel mode; applications own its…
dougpuob
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IOCTL_DISK_GET_STORAGEID WinCE vs Linux difference?
I'm trying to match a function from a WinCE program in Linux.
The function uses a WinCE call zu output the SD cards identifier.
but the problem is that the WINCE function outputs
0280XXXXXX as as serial number - whereas I get the same number on…
Sebastian Heyn
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How to use writeb in ioctl function?
In my project,I want to use ioctl to write different format such as byte,word and so on.
static long fpgaIoctl(struct file *filePtr, unsigned int flag, unsigned long data)
{
SFPGA_IOCTL* pIoctl = (SFPGA_IOCTL*)data;
//struct DevInfo_t *devInfo =…
Cengizhan Yapıcıoğlu
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why does ioctl I_SENDFD return no permission (EPERM)?
I want to send a file descriptor of a tcp socket from process A to process B, so that process B can create another tcp socket with the same file descriptor.
the idea is exactly the same as passing file descriptors
the key function call is the…
Bill Yan
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Unwanted side-effects when modifying IP address with ioctl
Question:
Is there a way of using ioctl to change only a desired interface component without affecting the other parts of the network interface?
Reasoning
I'm writing a C++ program that allows a user to change the IP address, Broadcast address,…
adanmoran
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2 answers
Debian I2C driver for OLED screen not working. [ssd1306]
I have some driver code that I am testing out for use with an SSD1306 driven OLED screen which is 128x32 (same as the OLED adafruit model). I need this to run in debian (I am using Linario-4.4.9)
I have followed the Debian guides on how to start…
Tropical_Peach
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how can i retrive the magic value from a _IOW macro generated ioctl number
I'm relatively new to linux drivers and am facing an issue in setting up ioctl numbers. I have a character driver where I've implemented an ioctl that can be called from a user application. Currently, I've trying to implement the ioctl as a generic…
user806168
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