I am working with a Stamp9g20 embedded chip. It is based on the Atmel at91sam9g20 platform. For a client I need to upgrade the kernel to a newer version. After a bit of research, I landed on the Linux4SAM pages and their additional yocto layer, complete with a 4.14 kernel! However, when I compile that kernel,…
Tag: embedded-linux
How and when are interrupt key combination,such as CTRL-C, translated to signals?
Using a Linux OS, I need to transparently pass all keystrokes from remote connections to local hardware connections. This is fairly straight forward for everything but signals. I know I can register handlers for each signal that capture and pass the keystroke, but this seems like a hack that might not work fo…
How to fix linker warning: “function undefined” in kernel space?
I’m working on an integrated SDK for powerpc microprocessor which has some kernel modules. The kernel(3.12.37) and toolchain(powerpc gcc 4.9.2) provided by Yocto project. When i make SDK in native machine(x86_64bit Ubuntu 14) by mentioned toolchain and kernel source, I see these warnings during compilat…
which utility produces “Poky (Yocto Project Reference Distro) 2.6.1 (none) /dev/console”
I am playing with Yocto Thud 2.6.1. I want to know which utility / program / library is responsible for producing following line: ‘Poky (Yocto Project Reference Distro) 2.6.1 (none) /dev/console’ Thanks Answer The lines before the login are from the /etc/issue and /etc/issue.net files. You can mod…
What could be the difference between an embedded serial read operation and a Desktop- PC
In an embedded Linux system, I am coding the project which tests serial port in a pyhsically loopback environment. It means I am connecting rx-tx.The peripheral output is RS-232 In order to test the port I am sending 1 byte then I read the sent byte. I repeat this cycle from 0x00 to 0XFF. I am using raw input…
Debian 9.4 (stretch) change UART4 baud rate to 9600
I researched and tried a lot updating uart4 baud rate of Beaglebone green running Debian 9.4, but could not succeed. I am not even sure whether uart4 is enabled in Debian 9.4. As per am335x-boneblack.dts, uart4 is disabled and clock-frequency value is 0x2dc6c00 (this is for baudrate 115200 I guess). Answer I …
How to make gdb for a target and use it there
I am trying to compile gdb-8.2 from source. Build machine: x86-64 Host AND target: arm-linux-gnueabi I ran: Then I ran: So I got a usr folder inside gdb_installation folder. I copied the usr/local/bin/gdb to my target and ran Output: But it does not show anything. It exits without any message. What am I missi…
Segmentation fault when maping /dev/mem
I’m trying to mmap a memory from my FPGA on a linux running on my Zedboard SoC. I can read the contents correctly using devmem on the command line, but when trying to read it through C I get a segmentation fault. The barebones code shown below throws the segmentation fault when trying to print the conte…
libva version error on yocto build
I was trying to build a Yocto Image for intel processor. I downloaded the latest source code of poky and then clone the meta-intel branch and added it to bblayers.conf file. I started build with the following command And got the following error: I have the following recipe in this folder meta/recipes-graphics…
How u-boot start instruction is found by ROM Code
I am trying to understand ARM Linux Boot Process. These are the things I understood: When reset button is pressed in any processor, it jumps to the reset vector or address, in case of ARM it is either 0x00 or 0xFFFF0000. This location contains the start up code or ROM Code or Boot ROM Code My query is how thi…