Hi @Sean Liming I'm glad that you were able to resolve your issue and thank you for posting your solution so that others experiencing the same thing can easily reference this! Since the Microsoft Q&A community has a policy that "The question author cannot accept their own answer. They can only accept answers by others ", I'll repost your solution in case you'd like to accept the answer .
Issue:
Setting a GUIX application on STM32H747-DISCO blows out the available SRAM (.bss) section by over 275K.
Solution:
GUIX Studio has options to allocate canvas memory. Works well for a Windows app, but not needed to be set at this point when running on an MCU.
If I missed anything please let me know and I'd be happy to add it to my answer, or feel free to comment below with any additional information.
I hope this helps!
If you have any other questions, please let me know. Thank you again for your time and patience throughout this issue.