• ISELFinalProjectInfo

ISELFInalProjectInfo

Information about several subjects regarding the ISEL final project.

Linux Kernel

https://www.kernel.org/pub/linux/kernel/v3.x/linux-3.13.5.tar.xz

Linux Device Drivers book

http://lwn.net/images/pdf/LDD3/ldd3_pdf.tar.bz2

sysfs

http://lxr.free-electrons.com/source/Documentation/filesystems/sysfs.txt

What it is:

sysfs is a ram-based filesystem initially based on ramfs. It provides a means to export kernel data structures, their attributes, and the linkages between them to userspace.

sysfs is tied inherently to the kobject infrastructure. Please read Documentation/kobject.txt for more information concerning the kobject interface.

• /usr/src/linux-3.2.45/Documentation/filesystems/sysfs.txt

Create entry / attributes

https://godandme.wordpress.com/2011/04/05/how-to-make-a-sysfs-entry/

http://stackoverflow.com/questions/11063719/kernel-modules-parameters-in-sysfs-quick-reaction-for-changes

http://stackoverflow.com/questions/11067262/getting-parent-for-kobject-add

IIO

Adapted from http://wiki.analog.com/software/linux/docs/iio/iio

The Industrial I/O subsystem is intended to provide support for devices that in some sense are analog to digital or digital to analog convertors (ADCs, DACs). Devices that fall into this category are:

• ADCs
• Accelerometers
• Gyros
• IMUs
• Capacitance to Digital Converters (CDCs)
• Pressure Sensors
• Color, Light and Proximity Sensors
• Temperature Sensors
• Magnetometers
• DACs
• DDS (Direct Digital Synthesis)
• PLLs (Phase Locked Loops)
• Variable/Programmable Gain Amplifiers (VGA, PGA)

SPI

I2C

ARM AT91SAM9260B

http://www.atmel.com/devices/sam9260.aspx

A 210MHz ARM926-based processor with an extensive range of communication peripherals. It embeds FS USB host and device interfaces, a 10/100 Ethernet MAC and an image sensor interface, as well as standard peripherals such as a Multimedia Card Interface (MCI), I2S, USARTs, master/slave SPIs, 16-bit Timers, a TWI and four-channel 10-bit ADC. The external bus interface features controllers for SDRAM and static memories including NAND flash and CompactFlash. The SAM9260 is available in 217-ball LFBGA and 208-pin QFP packages.

Linux4SAM

http://www.at91.com/linux4sam/bin/view/Linux4SAM/WebHome

http://www.at91.com/linux4sam/bin/view/Linux4SAM/GettingStarted

http://www.at91.com/linux4sam/bin/view/Linux4SAM/IioAdcDriver

FXOS8700CQ

http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=FXOS8700CQ

Freescale’s FXOS8700CQ 6-axis sensor combines industry leading accelerometer and magnetometer sensors in a small 3 x 3 x 1.2 mm QFN plastic package. The 14-bit accelerometer and 16-bit magnetometer are combined with a high-performance ASIC to enable an eCompass solution capable of a typical orientation resolution of 0.1 degrees and sub 5 degree compass heading accuracy for most applications.

Hello world linux kernel module on Slackware 14

• su
• cd /usr/src/linux/
• mkdir helloWorld
• nano Makefile

obj-m = helloWorld.o
KVERSION = $(shell uname -r)
all:
        make -C /lib/modules/$(KVERSION)/build M=$(PWD) modules
clean:
        make -C /lib/modules/$(KVERSION)/build M=$(PWD) clean

• nano helloWorld.c

   1 #include <linux/module.h>       /* Required by all modules */
   2 #include <linux/kernel.h>       /* Required for KERN_INFO */
   3 #include <linux/init.h>         /* Required for the macros */
   4 
   5 static int __init helloworld_init(void)
   6 {
   7     printk(KERN_INFO "Hello world\n");
   8 return 0;
   9 }
  10 
  11 static void __exit helloworld_exit(void)
  12 {
  13     printk(KERN_INFO "Bye all.\n");
  14 }
  15 
  16 module_init(helloworld_init);
  17 module_exit(helloworld_exit);

• make
• tail -f /var/log/messages
• insmod helloWorld.ko
• /sys/module/helloWorld # module !!!
• rmmod helloWorld.ko