mirror of
https://github.com/trezor/trezor-firmware.git
synced 2024-12-23 14:58:09 +00:00
92 lines
3.1 KiB
Markdown
92 lines
3.1 KiB
Markdown
|
# Debugging events with SystemView and Real-time Terminal (Trezor T only)
|
||
|
|
||
|
Systemview is an utility to debug interrupts or other events, counters, logs
|
||
|
which does not require any extra pin (except the SWD pins attached to CPU).
|
||
|
|
||
|
An example showing two interrupts, and debug log passed via memory instead of UART.
|
||
|
|
||
|
![SystemView](SystemView_debug_interrupts.png)
|
||
|
|
||
|
Second example is RTT with color logging (kind of subset what SystemView can do,
|
||
|
sans the colors).
|
||
|
|
||
|
![Realtime Terminal](RTTViewer_20201215_165241.png)
|
||
|
|
||
|
Compared to UART the speed of counters or messages is enormously faster as SystemView
|
||
|
does trick where it stores all in a small location in RAM (cyclic buffer)
|
||
|
|
||
|
This requires JLink/JTrace adapter and [SystemView](https://www.segger.com/products/development-tools/systemview/)
|
||
|
installed. SystemView is available as free/educational or commercial licensed.
|
||
|
|
||
|
## Building with SystemView enabled
|
||
|
|
||
|
Clean build in `core`:
|
||
|
|
||
|
make clean
|
||
|
|
||
|
### Enable SYSTEM_VIEW
|
||
|
|
||
|
Change in `SConscript.firmware`: `PYOPT` to `0` (not strictly necessary, but you won't see
|
||
|
debug messages otherwise, though this enables to use it also on non-debug build).
|
||
|
|
||
|
Then it's suggested to change `OPTIMIZE` to `-Og` instead of `-Os` which will still
|
||
|
does optimizations, but only a subset that does hinder debug by reordering
|
||
|
instructions.
|
||
|
|
||
|
PYOPT = ARGUMENTS.get('PYOPT', '0')
|
||
|
COPT=os.getenv('OPTIMIZE', '-Og')
|
||
|
|
||
|
Then enable the SYSTEM_VIEW feature in `FEATURE_FLAGS`:
|
||
|
|
||
|
FEATURE_FLAGS = {
|
||
|
"RDI": True,
|
||
|
"SECP256K1_ZKP": False,
|
||
|
"SYSTEM_VIEW": True,
|
||
|
}
|
||
|
|
||
|
|
||
|
Then in `core/src/trezor/log.py` change color to False, SystemView does not support
|
||
|
colorful messages (lines will be garbled), but if you want colors you can also use
|
||
|
Real-time terminal (RTT, see below)
|
||
|
|
||
|
set color = False
|
||
|
|
||
|
Then build with (change PYOPT or BITCOIN_ONLY as needed):
|
||
|
|
||
|
V=1 VERBOSE=1 PYOPT=0 BITCOIN_ONLY=1 SYSTEM_VIEW=1 make build_embed
|
||
|
|
||
|
After flashing with:
|
||
|
|
||
|
make flash_firmware_jlink
|
||
|
|
||
|
You should be able to conect with SystemView or RTT and collect the data and analyze
|
||
|
them.
|
||
|
|
||
|
### Sending data to RTT instead of SystemView
|
||
|
|
||
|
There are two mutually exclusive macros, first one is turned on by default and sends
|
||
|
data to SystemView. Changing data sending to RTT is just undefining first and defining
|
||
|
second (in theory it could be able to send to both destinations, but never tried it.)
|
||
|
|
||
|
* `SYSTEMVIEW_DEST_SYSTEMVIEW`
|
||
|
* `SYSTEMVIEW_DEST_RTT`
|
||
|
|
||
|
Now when you run `JLinkRTTViewerExe` you should see data in the terminal:
|
||
|
|
||
|
![Realtime Terminal](RTTViewer_20201215_165241.png)
|
||
|
|
||
|
It is possible to extend this mechanism to include multiple streams/terminals.
|
||
|
Terminals work like a usual terminal, so you can use it in debugging also for
|
||
|
user input.
|
||
|
|
||
|
## Combining SystemView/RTT with other debug tools
|
||
|
|
||
|
In general you can use SystemView along with GDB/CLion/Ozone or other debugger at the
|
||
|
same time, it's just advised that you keep all connections at the same frequency,
|
||
|
otherwise it may lead to unexpected behavior, weird resets, etc.
|
||
|
|
||
|
So e.g. you can profile the interrupts, DMA in SystemView while also profiling it on
|
||
|
instruction-level scale in Ozone:
|
||
|
|
||
|
![Ozone ETM trace with code profile](Ozone_ETM_trace_code_profiling.png)
|