# Keystone Bootable SD Card Issue with Freedom U740 Bootloader

**URL:** <https://forums.sifive.com/t/keystone-bootable-sd-card-issue-with-freedom-u740-bootloader/7115>\
**Category:** HiFive Unmatched\
**Created:** [March 13, 2025, 8:18pm UTC](https://forums.sifive.com/t/keystone-bootable-sd-card-issue-with-freedom-u740-bootloader/7115 "2025-03-13T20:18:23Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![nikhileshkverma](https://avatars.discourse-cdn.com/v4/letter/n/b487fb/32.png) [@nikhileshkverma](https://forums.sifive.com/u/nikhileshkverma)\
**Post date:** [March 13, 2025, 8:18pm UTC](https://forums.sifive.com/t/keystone-bootable-sd-card-issue-with-freedom-u740-bootloader/7115/1 "2025-03-13T20:18:23Z")

</div>

Hello SiFive Community,

I’m currently working on creating a Keystone bootable SD card for my board, but I’ve encountered an issue related to the bootloader. I have been following the documentation for the HiFive Unleashed board (which uses the Freedom-U540 bootloader), but my target environment utilizes the Freedom-U740 bootloader. The differences between these two appear to be causing compatibility issues.

As we are new to Hifive Unmatched, a detailed guide or any advice on adapting the bootloader for the Freedom U740 would be very helpful. For reference, here are the relevant resources:

> **[GitHub - keystone-enclave/freedom-u540-c000-bootloader: Freedom U540-C000 Bootloader Code](https://github.com/keystone-enclave/freedom-u540-c000-bootloader)**
>
> Freedom U540-C000 Bootloader Code

> **[HiFive Unmatched — Das U-Boot unknown version documentation](https://docs.u-boot.org/en/latest/board/sifive/unmatched.html)**