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Linux and priorities within kernel space
I have maybe stupid question. From QNX I know every each driver acts
as process having threads. Each thread has schedulinng scheme and it’s
own priority. How it’s in Linux? I mean no user space, but kernel
space. It looks for me like unpredictable bunch of mess. Can I somehow
manage priorities even for the drivers? I’m using Denx’s distribution.
Or do I have to use some extensions?
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X-No-Archive:yes A certain Mad@Spammers, of comp.arch.embedded "fame", writes : gtI would appreciate having hints on how to do it or pointers to gtdocumentation and example code if available.dear sir, may i know whether the VB coding provided by you works in Kernel space or not.Coz without having access to Kernel space how can we let control the Mouse movements.This VB code works in User space i suppose.So do i need to write a Mouse device driver for Kernel space or will this VB code works properly.If yes how?? pls replyHi, I would like to take advantages of the hardware TWI (I2C) functionality, which is available on the AT91SAM9G20. Therefore, I would like to write a Linux kernel module for it. However, when reading the documentation in the Linux kernel source tree regarding TWI (Linux kernel 2.6.30.9), I see some "worrying" comments. To start with, in the file /linux-2.6.30.9/drivers/i2c/busses/Kconfig, I read the following: Quote:Hello everybody I need to write my own uart driver (kernel module) for AT91SAM9260. How can I shutdown linux uart driver at the runtime to startup my driver without any collisions? I wrote kernel module and compiled linux kernel without uart's supply, but when I allow TXRDY interrupt in US_IER register, linux is hunging for ever. But there is a silence on the uart line. Maybe I just can run my kernel module instead of module that compilled with kernel and maybe I don't need to compile kernel without uart's supply? Help me please) My major target is to do all uart routines ...Hai everybody, Iam currently working on the ARM9 board, Now iam writing an Application to the ARM9, to change the MAC id throught the user space. Currnetly only in u-boot we can change the mac address, this all arguments are stored in EEPROM (i.e nothing but i2s EEPROM)when kernel boots the u-boot passes the arguments to the kernel (arguments are ipaddr, macaddr, serveraddr, baudrate, amp some....) If we change in the kernel level if we reboot the board again it will get the previous Arguments only, but i want to change the globally we need to change in the eeprom through iser space i have ...Hi there, I want to use the two PWM channels of the Grasshopper. Due to the message during startup (see below) and the directories under /sys the atmel_pwm driver seems to be installed and working. But how can I communicate with the driver? Is there a similiar interface like for the leds or gpios? Probably it is quite simple - if you know what to do. Generally where can I find such information, only in the kernel source, header, document folder or are there other places to look? I am quite new to hardware programming in Linux and have ...Hi y'all Quick but not so easy question (it may spawn a considerable thread...) We need to develop a cooperative multitasking kernel for various embedded platforms (See the implications and the complications?). One requirement is that c-functions should serve as "tasks". (Notably, these tasks perform very simple functions, e.g. polling push buttons, occasionally updating a display, polling an adc, and a whole slew of other things that are definitely not time critical.) The question is, how should cpu time be distributed, given the following: Task 1: Priority 1 Task 2: Priority 1 Task 3: Priority 1 Task 4: Priority 1 ...Hi Guys I have recently bought a single board computer that has the atmel AT91SAM9260 core on board and I have a linux file system installed on this. I have updated my kernel to 2.6.30 so that I have the GPIO driver and can now access GPIO from user space. However I would like to get access to the ADC inputs and PWM outputs in a similar way, is this possible? If so could someone point me in a direction on this? If it's not possible could someone suggest ways of doing this? I presume I would have to write my ...Hello, i wrote a small programm that needs to communicate with the host computer through the USB interface. For this purpose, I need to change the device, string, endpoints descriptors so that the device can be used in windows (and in Linux OS) as a HID or massive storage device with the specific vendor ID and product ID. Can anybody tell me how to do it (preferably in the user space)?? The linux kernel version is 2.6.27. I attached a file that lists the available device drivers in the dev/ directory (less proc/devices) Is that an Idea trying to use usb_endpoint or usb_device? Thanks ...Hi forum, as a newbie to linux on ARMs I learned a lot about the architecture of raspberrypi over the last few weeks and I'm really looking forward to my first board. While waiting for the board I tried to compile a kernel today and prepare an image. My plan is to start with the "official" kernel from kernel.org, patch it and crosscompile it (all on my Ubuntu system). I got the kernel sources and found a patch for raspberrypi on github. So I copied them via git clone https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.gitgit clone https://github.com/simoncadman/Raspberry-Pi-Kernel-Patch.git However, when I try to patch the kernel, I get various messages ...I have succesfully built 2.6.23.atmel.5 kernel and it is running well in NGW100. (it is patch with ISI patches from avr32linux.org) But when i used the same linux kernel on AP7000 OEM from ICnova, the uboot is able to read the kernel image, but does not continue to display the booting sequences message. Is there any setting i need to edit? I also curious if the ISI patch is compatible to the current linux kernel. :-SA very useful article about Threading in .NET Micro Framework by NETMF team: http://blogs.msdn.com/b/netmfteam/archive/2011/01/17/threads-and-thread-priorities-in-netmf.aspx?wa=wsignin1.0Hello all, We have a customer who wants to use XBee device integrated into a BACNet or MODBUS application network, with intention to be able to carry "any" application protocols, not only the BACNet or MODBUS. The target OS is Linux running on an embedded (not much powerful) computer. Apparently, we have to somehow abstract the XBee device as a new MAC layer to the Linux network stack, so the upper layer application would address the Xbee devices in the mesh using the known socket interface. Is there anybody who had such experience, or just can share their thoughts? As far as I understand, what ...Hi friends, I have ported Linux-2.6.30 to AT91SAM9261-EK, I have compiled my kernel with following option enabled 1. in Kernel Hacking sub-menu and select these options: [*] Kernel debugging lt-- not sure about this one [*] Compile the kernel with debug info [*] KGB: kernel debugging with remote gdb ---gt[*] KGDB: use kgdb over the serial console After doing this i have flashed the kernel to SAM board, But after booting no change, My target board is not waiting for GDB connection from Host. Please any one can help me. Is there any KGDB patch for Linux 2.6.30 for AT91SAM9261. Tell me what all the things ...I'm using ARM Cortex-R4 for my system. I'm little bit confused about which linux should I go for - Standard Linux Kernel with MMU disabled or uCLinux. On an eval board, I have run the standard kernel compiled with MMU disabled. I used cramfs filesystem which available on the official ARM website. After the kernel boots up, I receive the shell but I couldn't do much experimentation as I found that most of the time, the shell stops responding (particularly when I press for auto-completion). So, I'm still not sure whether MMU less kernel shall run smoothly if I use ...Hello. I'm using an AT91SAM9GS45-EKES board and Linux Kernel 2.6.36. I'm having problems to have the MMC adaptor working on this kernel. The original kernel that came with the board was 2.6.30 and the MMC worked just fine. The reason I changed to 2.6.36 is that I need to use USB Wi-Fi adaptors and the Modules for these adaptors only exists on 2.6.36. I noticed that for this specific board kernel 2.6.33 has been used too. Unfortunately this kernel does not have the modules I need for USB Wi-Fi adaptors. Reading dmesg dump I noticed that MMC won't even be detected. On kernel ...I am working on getting an I2S driver written, compiled and installed for this board. As my first step, I am working with the atmel-ssc.* driver supplied with my linux distro. I have compiled the ssc driver and have copied it to the ICnova board; however, when I run "insmod atmel-ssc.ko", the following appears: insmod: cannot insert 'atmel-ssc.ko': No such device (-1): No such device Here is the output into the /var/log/messages log: Mar 2 11:05:59 icnova user.debug kernel: kobject: 'atmel_ssc' (c0857d28): kobject_add_internal: parent: 'module', set: 'module' Mar 2 11:05:59 icnova user.debug kernel: kobject: 'holders' (93d7d320): kobject_add_internal: parent: 'atmel_ssc', set: 'ltNULLgt' Mar ...Hi! In Linux, is it possible for a process to access a buffer whose starting address is out of the process's space? The process will obtain the address from IPC. Will such memory access be prohibited by Linux OS or the processor? BRs, // CharlieMy code works as follows to display plenty of user feedback during boot: 1) My Atmel Bootstrap loads an 8bit BMP 480x272 out of Serial Flash and Splashes the screen in 32 bit TFT mode then loads U-Boot 2) U-Boot adds a small progress bar to this screen by customizing the function 'void show_boot_progress (int val)' 3) The Linux Kernel loads and as soon as it allocates the memory for the frame buffer (for the first time), it copies the BMP from my Bootstrap LCD buffer in PHYS DRAM to the new allocated frame buffer in VIRT DRAM. Any new allocates of the ...Hi, How can I set unique MAC address for linux? If I set ethaddr variable in u-boot, and run netinit, it works, but linux kernel (2.6.22) don't use this MAC address (change to a default MAC). The only way to set MAC is kernel source hacking (drivers/net/arm/at91_ether.c), but it's not a good solution. Can anybody help me? Thanks, BB