STOP 0x124 errors are mostly hardware problems (but can be due to a few different driver issues).
To start, blow out all the vents with canned air (DO NOT use an air compressor or vacuum as they can cause damage to to your system). Only use the laptop on a hard surface - and I also recommend using a laptop cooler to ensure that the system is getting adequate cooling airflow.
The "firmware" issue is most likely a BIOS update. Have you checked those?
Please provide this info so we can have a deeper look at the issues you're experiencing: Link Removed