eBay Mini ST-Link v2 knockoff and an EMW3165/WiFiMCU. The adventure begins by trying to back-up the WiFiMCU's firmware with texane's st-link utility. Curiously, the flash dump is short and sequential flash dumps don't have matching output. 60-64 bytes is zeroed out randomly throughout the dumps.

OpenOCD with gdb remote appear to dump just fine. Several pull requests later, and upgrading the ST-Link firmware to V2J24S4 resolves most of the problems. I can get mostly consistent output from the ST-Link when dumping the flash from 0x8000000 to 0x8080000 with only 2 corruptions out of 7500.