Summary of What Does a CPU Do Before Going to Work (in an Embedded System)? - Josef Holzmayr, Mender.io

00:00:00 - 00:35:00

The CPU in an embedded system does a number of tasks before it begins work, including initializing the system's hardware and preparing the system for booting. This talk by Josef Holzmayr covers the various stages a CPU goes through during its pre-work activities.

• 00:00:00 The CPU does various things before going to work, including initialization and powering down systems. This talk is about the CPU pre-work activities in an embedded system.
• 00:05:00 This video explains what a CPU does before going to work in an embedded system. It covers the stages an embedded CPU goes through when it starts up, including the initialization of the system's flash memory. The video then moves on to discuss how a microcontroller behaves when it is powered on.
• 00:10:00 In stage two of a CPU's initialization sequence, the CPU becomes aware of external memory and starts accessing it. In order to do this, it needs to know how to connect to the memory and how to read the data from it. Pull-ups and pull-downs are used to control the flow of current to and from the pins, allowing the CPU to access the memory without being bogged down by excessive current.
• 00:15:00 CPUs in embedded systems run code that is usually very proprietary, and often requires a special bootloader to be loaded before the code can run. CPUs in the fourth stage of development are those that are capable of running an operating system directly on the microcontroller, without the need for a higher level of software.
• 00:20:00 The CPU does some initialization tasks before going to work, including memory initialization and loading the operating system. The bootloader, which gets kicked off at the first step, is a small monolithic OS that does memory management, protection, and other tasks.
• 00:25:00 The CPU does various pre-operational tasks before going to work in an embedded system, such as executing the application, fetching Linux from ROM, and handing off to the operating system.
• 00:30:00 The CPU does various tasks before going to work, including taking a shower, eating breakfast, and putting on cowboy boots. The boot process is chain-like, with various stages being completed as the CPU goes along. If a bootloader is present, it will take over from there, loading the specific software needed for the device. Over-the-air updates are handled by the bootloader, and it is important for it to kick in early during the boot process in order to ensure that the updates run successfully.
• 00:35:00 The CPU in an embedded system does various tasks before it goes to work, including preparing the system for booting and initializing the system's hardware.