The iOS 17.5.1 (21F90) firmware is the latest official version of the operating system for the iPhone 15 Pro Max. This firmware includes numerous improvements and fixes aimed at enhancing the stability and security of the device. In this article, we will look at the process of re-flashing the iPhone 15 Pro Max to iOS 17.5.1, as well as verifying the hash of the downloaded firmware to ensure its authenticity.
What is iOS 17.5.1 (21F90) Firmware?
iOS 17.5.1 (21F90) firmware is an operating system update for the iPhone 15 Pro Max, released in May 2024. It includes important security fixes and stability improvements, making it recommended for all users of this device.
Firmware Hash Sums
To verify the authenticity of the firmware file, use the following hash sums:
- SHA256:
89e1eed78fb37c96e5d98f0dbf9e1569ee63e83b05657226ace2f70df803cd14 - MD5:
bf865b8f3977e2c09732a42822206e20 - SHA1:
09ec0f44cb82f421af2f5fcbfa7de3beec59570e
Step 1: Preparing for Re-flashing
- Make sure you have iTunes installed (for Windows and macOS) or idevicerestore (for Linux).
- Connect the iPhone 15 Pro Max to your computer using a USB cable.
Step 2: Checking the Hash of the Downloaded Firmware
Windows:
- Open PowerShell and navigate to the folder with the firmware file, for example,
cd Downloads. - Enter the command:
Get-FileHash iPhone16,2_17.5.1_21F90_Restore.ipsw -Algorithm SHA1
- Compare the obtained hash with the one listed above.
macOS:
- Open Terminal and navigate to the folder with the firmware file, for example,
cd ~/Downloads. - Enter the command:
openssl sha1 iPhone16,2_17.5.1_21F90_Restore.ipsw
- Compare the obtained hash with the one listed above.
Linux:
- Open Terminal and navigate to the folder with the firmware file, for example,
cd ~/Downloads. - Enter the command:
openssl sha1 iPhone16,2_17.5.1_21F90_Restore.ipsw
- Compare the obtained hash with the one listed above.
Step 3: Re-flashing the iPhone 15 Pro Max
Windows (using iTunes):
- Open iTunes.
- Put the iPhone into recovery mode: Turn off the iPhone, hold down the Home button, and connect the device to your computer. Keep holding the Home button until the recovery mode screen appears.
- Press and hold the Shift key and click “Restore iPhone”.
- Select the firmware file
iPhone16,2_17.5.1_21F90_Restore.ipswand confirm the restoration.
Windows (using 3uTools):
- Download and install 3uTools from the official website.
- Put the iPhone into recovery mode, as described above.
- Go to the “SmartFlash” section and select “Easy Flash”.
- Click “Import Firmware” and select the firmware file
iPhone16,2_17.5.1_21F90_Restore.ipsw. - Click “Flash” and wait for the process to complete.
macOS:
- Open Finder.
- Put the iPhone into recovery mode, as described above.
- Press and hold the Option key and click “Restore iPhone”.
- Select the firmware file and confirm the restoration.
Linux:
- Install idevicerestore (follow the instructions on GitHub).
- Put the iPhone into recovery mode, as described above.
- Open Terminal and navigate to the folder with the firmware file.
- Enter the command:
idevicerestore -e iPhone16,2_17.5.1_21F90_Restore.ipsw
- Wait for the restoration process to complete.
Device Description: iPhone 15 Pro Max
The iPhone 15 Pro Max was released in September 2023. It is the latest flagship smartphone from Apple, bringing significant improvements over previous models. It features a 6.7-inch Super Retina XDR display with a resolution of 2778×1284 pixels, an A17 Bionic processor, and 8GB of RAM. The device has a 48 MP camera system and supports 4K video recording. The iPhone 15 Pro Max runs on iOS 17.5.1 — the latest official version of iOS for this device. Support for the iPhone 15 Pro Max continues, with new updates and improvements expected in the future.
By following these instructions, you can successfully re-flash your iPhone 15 Pro Max to iOS 17.5.1 and ensure the authenticity of the downloaded firmware.
