Boot loaders can be laden with features, but their primary Embedded Systems responsibility is to get the processor initialized and ready to run the operating system. In most modern embedded Linux systems, the kernel is stored in a partition in flash memory. The boot loader copies that flash partition into a certain location in RAM, sets the instruction pointer to that memory location, and tells the processor to start executing at the instruction pointer’s current location. After that, the program that’s running unceremoniously writes over the boot loader.
The important thing to note is that the boot loader is agnostic with respect to what is being loaded and run. It can be a Linux kernel or another operating system or a program written to run without an operating system. The boot loader doesn’t care; it performs the same Embedded Systems
basic actions in all these use scenarios. As boot loaders have matured, they’ve become more like operating systems with network, video, and increasing support for flash storage devices.
I look at the popular boot loaders you may encounter when working with Linux. One more important note: boot loaders are now ubiquitous. Rarely as an embedded Linux developer do you need to port a boot loader for your board. You may want to recompile the boot loader (I’ll cover that, too) to remove functionality to conserve space and increase boot time, but the low-level engineering is done by the board vendor.
What I should have done (had I really thought things through), is take advantage of the now-incubating Apache project, Builder. It’s basically a Maven-like build system with scripts based on Ruby and Rake. Instead of writing an epic-length POM file, you write a 10-20 line build file (which is actually a Ruby script with some DSL syntax) and Builder figures out the rest. Unfortunately, by the time I bethought myself of this option, I was almost finished with the Embedded Systems
Ant configuration, and I’m too stubborn to give up half-way through something.
Systems analysis is the specification of what exactly the system is required to do, or the main objective. Design is about how to make the system do what is required of it. For system analysis, it is required to study the current system by certain procedures in order to gather and interpret data and facts, identify any problems and use this Embedded Systems data to improve the system currently in use. System design refers to the process of developing a new system, concentrating heavily on the technical specifications and other specifications that make the Embedded Systems operations.
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