Keil5 Firmware Upgrade Practical Guide

# 1. Overview of Keil5 Firmware Upgrade

Firmware upgrade is a crucial operation in embedded systems, allowing the system to update its software without replacing the hardware. Keil5, the industry-leading embedded system development environment, offers robust firmware upgrade functionalities, enabling developers to easily update the firmware of embedded devices.

In this chapter, we will outline the fundamental concepts of Keil5 firmware upgrades, including the principles and processes of firmware upgrades, common protocols and techniques for firmware upgrades, as well as the security and reliability of firmware upgrades.

# 2. Theoretical Foundation of Firmware Upgrade

### 2.1 Principles and Processes of Firmware Upgrade

Firmware upgrade is the process of replacing the existing firmware program in the device with a new version, usually involving the following steps:

1. **Prepare Firmware Files:** Create or obtain new version firmware files that contain all the code and data required for the device to operate.
2. **Load Firmware:** Transfer the firmware files to the device's memory.
3. **Verify Firmware:** Check the firmware file for integrity and absence of damage.
4. **Erase Old Firmware:** Delete the old version of the firmware from the device's memory.
5. **Write New Firmware:** Write the new version of the firmware into the device's memory.
6. **Restart Device:** Reboot the device to load the new firmware.

### 2.2 Common Protocols and Techniques for Firmware Upgrade

Firmware upgrade can utilize various protocols and techniques, including:

- **UART:** Universal Asynchronous Receiver/Transmitter, used for firmware transmission over serial ports.
- **USB:** Universal Serial Bus, used for firmware transmission over USB interfaces.
- **SPI:** Serial Peripheral Interface, used for firmware transmission over SPI interfaces.
- **I2C:** Inter-Integrated Circuit, used for firmware transmission over I2C interfaces.
- **OTA (Over-The-Air):** Used for firmware transmission over wireless networks (e.g., Wi-Fi, Bluetooth).

### 2.3 Security and Reliability of Firmware Upgrade

Since firmware upgrade involves modifications to the device, ensuring its security and reliability is of utmost importance. Some common measures for security and reliability include:

- **Firmware Signing and Verification:** Use digital signatures to verify the authenticity and integrity of the firmware files.
- **Secure Boot:** Verify firmware integrity during device boot-up to prevent loading unauthorized firmware.
- **Encryption:** Encrypt firmware files to prevent unauthorized access.
- **Backup and Recovery:** Create a backup of the device's current firmware before upgrading, so it can be restored in case of issues.
- **Progressive Upgrade:** Phase the firmware upgrade process to reduce the risk of upgrade failure.

# 3.1 Keil5 Firmware Upgrade Environment Setup

#### 3.1.1 Keil5 Software Installation and Configuration

**Steps:**

1. Download and install Keil5 software from the official website.
2. After installation, open Keil5, select "File"->"New"->"MDK-ARM Project".
3. Enter a project name in "Project Name", choose the project save path in "Location", and then click "Create".
4. In "Target Device", select the target device, in "Toolchain" select the compiler version, then click "OK".
5. In "Project Options" configure the following:
- **Output Directory:** Specify the output directory for compiled files.
- **Target:** Select the target device.
- **Toolchain:** Select the compiler version.
- **Debug:** Select the debug method (e.g., SWD, JTAG).

#### 3.1.2 Hardware Debugger Selection and Connection

**Steps:**

1. Choose a hardware debugger compatible with the target device.
2. Connect the debugger to the target device.
3. In Keil5, select "Debug"->"Connect", select the debugger type and click "Connect".
4. If the connection is successful, the target device information will be displayed in the "Target" window of Keil5.

**Parameter Explanation:**

- **Debugger Type:** Select a debugger type compatible with the target device (e.g., SWD, JTAG).
- **Connection:** Establish a connection with the target device.

**Code Block:**

// Setting up Keil5 Firmware Upgrade Environment
#include <stdio.h>

int main(void)
{
     // Keil5