embedded-linux

Please can someone give an simple example on how to use libnl to use nl80211. I tried to go through iw source code but it is very confusing. Can any one give a simple program on how to trigger nl80211 commands such as NL80211_CMD_GET_WIPHY using the libnl. Here is a very basic program sending a NL80211_CMD_GET_INTERFACE , and parsing out the interface type returned in the NL80211_CMD_GET_INTERFACE attribute. Beware, there is very little error checking here, you should not use any of this program as is! Almost all these functions can fail. #include "netlink/netlink.h" #include "netlink/genl

I am looking to write a PWM driver. I know that there are two ways we can control a hardware driver: User space driver. Kernel space driver If in general (do not consider a PWM driver case) we have to make a decision whether to go for user space or kernel space driver. Then what factors we have to take into consideration apart from these? User space driver can directly mmap() /dev/mem memory to their virtual address space and need no context switching. Userspace driver cannot have interrupt handlers implemented (They have to poll for interrupt). Userspace driver cannot perform DMA (As DMA

I'm learning the linux kernel internals and while reading "Understanding Linux Kernel", quite a few memory related questions struck me. One of them is, how the Linux kernel handles the memory mapping if the physical memory of say only 512 MB is installed on my system. As I read, kernel maps 0(or 16) MB-896MB physical RAM into 0xC0000000 linear address and can directly address it. So, in the above described case where I only have 512 MB: How can the kernel map 896 MB from only 512 MB ? In the scheme described, the kernel set things up so that every process's page tables mapped virtual addresses

i am trying to run an executable in linux shell ( OpenELEC on raspberry pi ) OpenELEC:~ # /storage/fingi/usr/lib/autossh/autossh -sh: /storage/fingi/usr/lib/autossh/autossh: not found What does the "not found" in this case mean ? If i try to do ldd: OpenELEC:~ # ldd /storage/fingi/usr/lib/autossh/autossh /usr/bin/ldd: eval: line 1: /storage/fingi/usr/lib/autossh/autossh: not found And if i do file: OpenELEC:~ # file /storage/fingi/usr/lib/autossh/autossh /storage/fingi/usr/lib/autossh/autossh: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), dynamically linked (uses shared libs), for

I'm running Ubuntu 12:04LTS and installed arm-linux-gnueabi C and C++ compiler. The compiled binary won't run on my target board. It looks like even if I specify the cpu and arch, the compiler still builds a binary for the wrong CPU. Instead of atm9tdmi it build and 7-A. Am I doing something wrong or is there something I should have configured? Thanks. ~/ArmTest$ arm-linux-gnueabi-g++-4.4 -mcpu=arm9tdmi -march=armv4t -O main.cpp -o CPPTest ~/ArmTest$ readelf -A CPPTest Attribute Section: aeabi File Attributes Tag_CPU_name: "7-A" Tag_CPU_arch: v7 Tag_CPU_arch_profile: Application Tag_ARM_ISA

I'm trying to cross compile a helloworld kernel (2.6.x) module for ARM architecture on my intel x86 host. The codesourcery tool chain for ARM is located at: /home/ravi/workspace/hawk/arm-2009q3 The kernel source is located at : /home/ravi/workspace/hawk/linux-omapl1 My Makefile: ARCH=arm CROSS_COMPILE=arm-none-linux-gnueabi obj-m := Hello.o KDIR := /home/ravi/workspace/hawk/linux-omapl1 PWD := $(shell pwd) default: $(MAKE) -C $(KDIR) SUBDIRS=$(PWD) modules clean: $(MAKE) -C $(KDIR) SUBDIRS=$(PWD) clean When i run make , the .ko produced is that of my host machine which means the makefile is