Flashcards in this deck (32)

• What is firmware?

  Firmware is low-level code that drives the system, stored in non-volatile memory, and performs direct hardware interactions.
  firmware definition
• Where is firmware stored?

  In non-volatile memory such as EEPROM or flash memory.
  firmware storage
• Is firmware application specific?

  Yes
  firmware functionality
• How does firmware relate to software and hardware?

  Firmware is positioned between application software/operating system and hardware, enabling direct hardware interactions.
  firmware relationship
• What diagram illustrates the relationship between software, firmware, and hardware?

  
  diagram firmware
• List the components involved in the firmware relationship diagram.

  • Application Software
  • Operating System
  • Drivers
  • Firmware
  • Hardware
  firmware components
• What aspects could firmware classification indicate?

  It suggests complexity and security measures of the firmware types.
  firmware classification
• What is a Type I Embedded System?

  General purpose OS-based; uses a popular OS like Linux retrofitted for embedded systems. Example: Linux on a router.
  embedded_systems type_i
• Describe the characteristics of Type I Embedded Systems.

  • Hardware interaction abstracted by the kernel
  • Custom components may be used
  • No loadable kernel modules
  embedded_systems characteristics
• What defines a Type II Embedded System?

  Embedded OS-based; uses a custom OS designed for embedded systems. Example: VxWorks on NASA's Curiosity Rover.
  embedded_systems type_ii
• What are the characteristics of Type II Embedded Systems?

  • Designed to solve custom challenges e.g. real time constraints
  • Often no MMU/virtual memory
  • Reduced functionality compared to traditional OSs
  embedded_systems characteristics
• What is a Type III Embedded System?

  No OS-abstraction; can be entirely custom. Example: Firmware on a Logitech G600 Mouse (Atmel ATmega32 HW).
  embedded_systems type_iii
• Identify a characteristic of Type III Embedded Systems.

  May include an 'OS-library' but system and application code are compiled together; no strict kernel/user separation.
  embedded_systems characteristics
• What are the advantages of classifying firmware?

  • Indicates firmware complexity
  • Provides intuition about possible security features
  firmware classification advantages
• How is firmware important in embedded systems?

  Firmware enables crucial low-level software functionalities for hardware operations.
  firmware embedded_systems
• What are the disadvantages of classifying firmware?

  • No insight about Instruction Set Architecture (ISA) and HW platform (black box problems; you'll that it failed but not why)
  • Cannot standardise firmware management based on HW alone as the same HW platform can be different types in different systems (role fluidity with HW)
  • Type II and Type III can be hard to distinguish.
  arm architecture
• Which ARM profile is optimized for rich operating systems and offers highest performance?

  Cortex-A
  arm cortex-a
• Identify the ARM profile designed for hard real-time applications.

  Cortex-R
  arm cortex-r
• Which ARM profile is best for low power and microcontrollers?

  Cortex-M
  arm cortex-m
• List typical uses of the Cortex-A ARM profile.

  • Mobile phones
  • Tablets
  arm cortex-a applications
• Describe the optimization focus of the Cortex-R ARM profile.

  Fast response for high performance, hard real-time applications.
  arm cortex-r
• List typical uses of the Cortex-R ARM profile.

  • Hard drives
  • Automotive chassis
  • Industrial robotics
  arm disadvantages
• What are common applications of the Cortex-M profile?

  • Wearables
  • Lighting
  • Headphones
  arm cortex-m applications
• What is firmware's role in embedded systems?

  It is crucial low-level software enabling hardware operations.
  firmware embedded_systems
• What does the instruction add r0, r1, r2 do?

  Adds the value in r1 to r2 and stores the result in r0.
  assembly instructions
• What does the instruction ldr r0, [sp] accomplish?

  Loads the value stored at the address in sp into r0.
  assembly instructions
• What is the purpose of the instruction str r0, [sp, 4]?

  Stores the value of r0 at the address calculated as sp + 4.
  assembly instructions
• Explain the function of bl 0x0800144.

  Branches to the instruction located at address 0x0800144.
  assembly instructions
• What type of memory structure is typical in deeply embedded firmware?

  Memory maps; A single physical address space where memory and peripherals are mapped at predefined addresses.
  embedded memory
• Do memory maps usually use virtual address spaces?

  No, there is generally no need for virtual address spaces in embedded systems.
  embedded memory
• What does the memory map include?

  • Processing Unit
  • Peripherals
  • Memory
  embedded memory
• Summarize the importance of firmware in embedded systems.

  Firmware is crucial low-level software that enables hardware operations.
  firmware embedded