When you insert LKM with insmod it does not seem to execute defined probe() function. What do I need to do to trigger it?
Background: trying to create driver for MAX14830 for old kernel (2.6.39). Cannot use one available (max310x.c) because of old kernel, no support for regmap etc. In the source tree of old kernel there is max3107 driver (same thing, but for 1 serial port, while 14830 has 4). Both drivers use probe functions for initialization, as the SOC communicates with MAX chip over spi. I want to develop driver as LKM first.
What could be my problem?
Related
I'm developing an application for STM32F4 with Azure RTOS Netx Duo. In particular I'm trying to adapt the example Nx_TCP_Echo_Server application for my board where is present the Ethernet Phy ADIN1200 produced by Analog Devices.
Note about example Nx_TCP_Echo_Server
The Nx_TCP_Echo_Server example application has been made for a STM32F429ZI-NUCLEO demo board (code of Nx_TCP_Echo_Server on github).
In the demo board STM32F429ZI-NUCLEO the Ethernet Phy is compatible with the lan8742 driver (see the lan8742 driver code on GitHub). Unfortunately the Ethernet PHY ADIN1200 present on my board is not compatible with that driver.
I have noted that the sixth parameter of the function nx_ip_create() is the pointer function nx_stm32_eth_driver.
This pointer function points to lan8742 driver.
Below I show the invocation of the function nx_ip_create() present in the file app_netxduo.c (code of app_netxduo.c) of the Nx_TCP_Echo_Server example application:
/* Create the main NX_IP instance */
ret = nx_ip_create(&IpInstance, "Main Ip instance", NULL_ADDRESS, NULL_ADDRESS, &AppPool, nx_stm32_eth_driver,
pointer, 2 * DEFAULT_MEMORY_SIZE, DEFAULT_PRIORITY);
The documentation of NetX Duo reports the following info:
The NX_IP structure contains everything to manage a single IP instance. This includes general TCP/IP protocol information as well as the application-specific physical network driver's entry routine. The driver's entry routine is defined during the nx_ip_create service. Additional devices may be added to the IP instance via the nx_ip_interface_attach service.
My development environment
My development environment is composed by:
STM32CubeMX version 6.7.0
In the STM32CubeMX I have installed the Package STM32F4 version 1.27.1
To use ThreadX I have added to CubeMX the software pack X-CUBE-AZRTOS-F4 version 1.1.0
By the previous environment I can find only the driver for LAN8742.
My question
How can I find other Ethernet PHY drivers for NetX Duo other than the one for lan8742?
EDIT
I have found this driver for ADIN1200 but it is very far from the driver lan8742.c provided by my development tool (see the code of lan8742).
In fact the API of the 2 drivers are very different; for example NetX Duo (and before it: LwIP) needs a function like LAN8742_RegisterBusIO() (present in the LAN8742 driver) to init a structure with pointer functions useful to write and read registers of the Ethernet PHY, but in this driver this function and its data structures are not present.
You can find different phy drivers from https://github.com/azure-rtos/samples.
mimxrt1060：KSZ8081RNB
same54：KSZ8091RNA
stm32f746：LAN8742A-CZ-TR
rx65n rsk：DP83620SQE
For others, you will need to develop the driver by yourself, based on existing ones.
I built a certain driver as module (m) for Linux, the spi-imx by NXP. Nontheless, Linux probes this driver when booting. I'm struggling to find out what process/other module/driver requests this spi-imx driver. A depmod does not show any dependencies between the spi-imx an other modules (except for the spidev as submodule).
After some research, I found out that Linux automatically (?) calls modprobe when it detects a new device. So does Linux actually call modprobe because the ecSPI'S status in the device tree as "okay"? If so, how can I prevent this? I would like to dynamically load the spi-imx from a user space application via modprobe. The story behind it: a coprocessor uses this SPI line in parallel to the Linux boot process. This interferes of course and interrupts the coprocessor's use of the SPI line. When the coprocessor has finished its transfer via SPI (a boot mechanism as well), it should hand over the SPI line to Linux.
I'm very thankful for any kind of tips, links, hints and comments on this.
Thanks a lot for the answers. As you guys mentioned, I also found out that Linux itself probes the device if present ("okay").
One possible solution is to complete cut off the modprobe call via an entry like "install spi-imx /bin/false" in the *.conf file. But that makes it impossible to load the driver via modprobe, for Linux and for user space.
"blacklist spi-imx" inside a *.conf located at /etc/modprobe.d/ is the way to prevent Linux from probing the driver when booting. After that, a modprobe from user space can successfully load the driver afterwards.
Thanks again & best regards
I'm trying to get MSI-X working on an iMX6 (Freescale/NXP/Qualcomm) CPU in Linux v4.1 for a PCIe character device driver. Whenever I call either pci_enable_msix() or pci_enable_msix_range() or pci_enable_msix_exact() I get an EINVAL value returned. I do have the CONFIG_PCI_MSI option selected in the kernel configuration and I am also able to get single MSI working with pci_enable_msi(), but I cannot get multiple MSI working either.
I have tested my driver code on an Intel i7 running kernel v3 with the same PCIe hardware attached and I was able to get MSI-X working without any problems so I know my code is correctly written and the hardware is correctly functioning.
When running on the iMX6 I can use lspci -v to view that the hardware has MSI-X capabilities and see the number of IRQs it allows. I can even get the same correct number in my driver when calling pci_msix_vec_count().Questions
Are there any other kernel configuration flags I need to set?
Is there anything specific to the iMX6 CPU I need to consider?
Does anyone have any experience with the iMX6 and either MSI-X or
multiple MSI?
Suppose I've got the following setup:
A Host which runs two KVM VMs(VM1 and VM2), a virtual bridge virbr, and two bridge taps vTAP1 and vTAP2. The VM's are attached to the vTAPS respectively.
I've got an application running on the host which measures different load metrics on the bridge. For achieving this it needs to acquire the vTAPS in order to stream the packets between the vTAPs through the bridge for measurement.
The problem is that I can't acquire the vTAPS, because the ioctl TUNSETIFF syscall fails with EBUSY errno.
I guess that it happens because the application(runned on the host) is not the owner of the taps(which owned by the VMs). Adding new temporary bridge vTAPS for measurement may not be always a solution because sometimes I would want to measure the flow directly between the VM vTAPS.
Attempted solution: There is a Multiqueue tuntap interface:
Linux supports multiqueue tuntap which can use multiple
file descriptors (queues) to parallelize packets sending or receiving. The
device allocation is the same as before, and if user wants to create multiple
queues, TUNSETIFF with the same device name must be called many times with
IFF_MULTI_QUEUE flag.
using IFF_MULTI_QUEUE stopped the ioctl from failing with EBUSY errno but it started failing on write syscall to the vTAP with EINVAL errno. So it didn't really solve anything.
I would appreciate any help, thanks.
I'd like to start service before user mode is loaded (in kernel mode).
The reason is I wanna run several system applications(asm code to write data to BIOS) that are not allowed in user mode (privileges problem).
That's why I got an idea: 1. Write windows service 2. Start and run it in kernel mode
Is it possible?
Are there any other ways to solve the problem?
I don't usually use Vista (use linux instead), that's why I'm asking.
Windows services are user-mode applications. To run in kernel-mode you should write a driver. (So-called "legacy" driver will be enough, see Driver Development Part 1: Introduction to Drivers).