Editing Embedded software (section)

==Differences from application software==
[[File:MicroVGA TUI demoapp.jpg|thumb|Embedded system [[text user interface]] using MicroVGA<ref group="nb" name="MicroVGA">For more details of MicroVGA see this [http://www.microvga.com/pdf/uvga-text-ds.pdf PDF].</ref>]]
Most consumers are familiar with [[application software]] that provide functionality on a computer. However embedded software is often less visible, but no less complicated. Unlike application software, embedded software has fixed hardware requirements and capabilities, and addition of third-party hardware or software is strictly controlled.

Embedded software needs to include all needed [[device driver]]s at manufacturing time, and the device drivers are written for the various hardware devices. These device drivers, called BSP ([[Board support package]]), form the layer of software containing hardware-specific drivers and other routines that allow a particular operating system (traditionally a real-time operating system, or RTOS) to function in a particular hardware environment (a computer or CPU card), integrated with the RTOS itself. The software is highly dependent on the CPU and specific chips chosen. Most embedded software engineers have at least a passing knowledge of reading [[schematic]]s, and reading data sheets for components to determine usage of registers and communication system. Conversion between [[decimal]], [[hexadecimal]] and [[binary numeral system|binary]] is useful as well as using [[bit manipulation]].<ref>{{cite web |title=Stroustrup on embedded software |url=http://www.www.stroustrup.com/Programming/25_embedded.ppt |access-date=9 December 2012 |url-status=dead |archive-url=https://web.archive.org/web/20130203113844/http://www.stroustrup.com/Programming/25_embedded.ppt |archive-date=3 February 2013 }}</ref>

Web applications are often used for managing hardware, although XML files and other output may be passed to a computer for display. File systems with folders are typically used, however SQL databases are often absent.

Software development requires use of a [[cross compiler]], which runs on a computer but produces executable code for the target device. Debugging requires use of an [[in-circuit emulator]], and debugging hardware such as [[JTAG]] or [[JTAG#Serial Wire Debug|SWD]] debuggers. Software developers often have access to the complete kernel (OS) source code.

Size of the storage memory and RAM can vary significantly. Some systems run in 16&nbsp;KB of Flash and 4&nbsp;KB of RAM with a CPU operating at 8&nbsp;MHz, other systems can rival contemporary computers.<ref>{{cite web|title=Example of embedded CPU|url=http://www.st.com/internet/mcu/product/216844.jsp|access-date=9 December 2012}}</ref> These space requirements lead to more work being done in C or [[embedded C++]], instead of C++. Interpreted languages like [[BASIC]] (while e.g. [[Parallax Propeller#BASIC compiler|Parallax Propeller]] can use compiled BASIC) and [[Java programming language|Java]]<!--at least was used, with ARM (and others) JVM bytecode in hardware--> (Java ME Embedded 8.3<ref>{{cite web |url=https://www.oracle.com/technetwork/java/embedded/javame/embed-me/downloads/java-embedded-java-me-download-2162242.html |title=Java ME Embedded |work=Oracle Technology Network}}</ref> is available for e.g. <!--STMicroelectronics--> [[ARM Cortex-M4]], [[Cortex-M7]] microcontrollers and older [[ARM11]] used in [[Raspberry Pi]] and [[Intel Galileo]] Gen. 2) are not commonly used; while an implementation of the interpreted [[Python (programming language)|Python]] 3 language{{snd}} [[MicroPython]]{{snd}} is however available expressly for microcontroller use, e.g. [[32-bit]] [[List of ARM Cortex-M development tools|ARM]]-based (such as BBC [[Micro Bit|micro:bit]]) and <!--say e.g. here? CC3200 seems to be ARM, so only other non-ARM:?-->[[16-bit]] [[PIC microcontroller]]s.