Most users double-click the GUI. Experts use the command line. To access -runtime Trace Mode-l, follow these steps:
| Problem | Likely Cause | Solution |
|---------|--------------|----------|
| SP Flash Tool says “No trace device found” | Device not in META/Brom mode | Re-enter Brom mode; check VCOM drivers |
| Traces are empty or garbage | Wrong baud rate / USB bulk config | Use USB 2.0 port (not 3.0); disable USB selective suspend in Windows |
| Device reboots when starting trace | Trace buffer memory conflict | Reduce buffer size; disable peripheral tracing |
| Timestamps are all zero | Timer not initialized | Add earlyprintk to kernel cmdline; use a later boot stage |
| “Overflow” errors in tool | Trace data rate > USB throughput | Filter events; increase USB buffer in tool options |
The purpose of this report is to document the functionality, implementation, and output of the Runtime Trace Mode feature within the Smartphone Flash Tool. This mode is designed to capture real-time logging and diagnostic data during the firmware flashing process.
In the ecosystem of mobile device maintenance, repair, and customization, few utilities are as powerful—and as misunderstood—as the Smartphone Flash Tool (SFT). Commonly known by implementations such as SP Flash Tool for MediaTek devices or Qualcomm’s QPST, SFT is the industry standard for writing firmware (flashing) onto the internal memory of smartphones. While most users interact with its basic "Download" or "Firmware Upgrade" options, advanced diagnostics and development rely on a lesser-known but critical feature: Runtime Trace Mode. This essay explores the purpose, mechanics, and practical applications of Runtime Trace Mode within Smartphone Flash Tools, arguing that it serves as an indispensable window into a device’s real-time behavior during low-level operations.
Unlike normal boot, enabling Trace Mode requires the device to enter META Mode or Preloader USB COM mode with trace buffers activated. The Preloader loads a tiny trace proxy firmware into internal SRAM, which configures the ETM/STM, allocates a circular buffer in DRAM, and streams data to the host via USB bulk endpoints.