Monday, August 22, 2016

Linux OS architecture for beginers

Linux kernel first coded by "Linus Torvalds", His M Sc thesis. Which over time got accepted by GNU and other open source and corporations which have started ceating thier OS based on the linux kernel developed by Linus, The real lime light was achieved by Linux for Android for mobile operating system.


I would be develing into the Linux OS Architecture in a detailed fashion in  different views,

  • Kernel Developers and Middle Ware developers
  • First Time Linux developers and Users 
So that Articles would help the people as per their tastes.






Linux and Flavors Boot process on X86 machines


Let us de chipper each stage for a better understanding. Intel has designed its chips to be back portable for the 80286 processor so when, ever the hardware reset or the power button is pressed the processor would kick up in the Real Mode and where the device can address a primary memory, RAM (Random Access Memory) of less than 1MB. Having said this, now BIOS would need to identify the capacity of the CPU and decide on setting the Real Mode of the operation once the initial kernel initialization is done.

BIOS Stage 

  • Stage One: BIOS initialization starts off when the system power button is pressed or the machine is reset. At this point of the time CPU is in real mode and would need to be reset to the real mode when the BIOS initialization starts and reads the MBR  to load the Boot Loader (here we refer to GRUB).


BootLoader Stage

  • Stage Two:  MBR would have the GRUB Position would be identified for the Processor to load the GRUB program.
  • Stage Three: This is the stage when the boot-loader would start executing and setting up the hardware for the kernel to load, Boot loader would know the path to the kernel and would load the kernel and call the Start() method of the linux kernel. 

Kernel Stage
This is stage where the CPU mode is shifted from Real Mode to Protected mode to take the benifit of the memory protection provided by the CPU which in turn allow the Linux kernel to provide multi-processing capacity to the users. Kernel loads the initrd or initramfs Which is a temporary file system and then kernel starts of the Init process which is the First User Mode , Process.




Sunday, August 21, 2016

Linux Introduction

Hello friends, This blog would start of with basic introduction on the Linux and general OS concepts and then slowly would start digging into the Android and other available Linux flavours

I would request the visitors to start giving their inputs for this blog so as to make it a beautiful place for the people who are in quest for the technology and learning OS concepts and Android Internals  





Friday, July 8, 2011