https://github.com/mattvenn/atmel-32u4-jtag-notes
My debugging notes with using avarice, avr-gdb, atmel mega 32u4 and dragon jtag
https://github.com/mattvenn/atmel-32u4-jtag-notes
Last synced: about 2 months ago
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My debugging notes with using avarice, avr-gdb, atmel mega 32u4 and dragon jtag
- Host: GitHub
- URL: https://github.com/mattvenn/atmel-32u4-jtag-notes
- Owner: mattvenn
- Created: 2017-09-20T07:45:51.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2017-12-22T09:20:43.000Z (over 7 years ago)
- Last Synced: 2025-04-01T18:09:53.362Z (about 2 months ago)
- Size: 1000 Bytes
- Stars: 4
- Watchers: 2
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
# JTAG test on 32u4
## enable JTAG
[fuse settings](http://www.engbedded.com/fusecalc/):
using avrdragon with ICSP cable attached to leonardo board's ICSP header.
avrdude -c dragon_isp -P usb -p atmega32u4 -v -U hfuse:w:0x98:m
avrdude -c dragon_isp -P usb -p atmega32u4 -v -U hfuse:w:0x18:m # includes OCDEN
OCDEN bit is the on chip debugging enable
avrdude -c dragon_isp -P usb -p atmega32u4 -v -U hfuse:w:0x19:m # bootrst vector
not sure if this actually made a difference, but this was the fuse used to do
the final debugging.
## make cable that connects the JTAG pins:
### dragon pins
1 TCK 2 0V
3 TDO 4 +v
5 TMS 6 nRST
7 n/c 8 n/c
9 TDI 10 0v
### 32u4 pins
pin fun arduino pin
-------------------
PF4 TCK analog3
PF5 TMS analog2
PF6 TDO analog1
PF7 TDI analog0
## read fuses with jtag
avrdude -c dragon_jtag -p atmega32u4 -v
## compile firmware with debugging
edit ./hardware/keyboardio/avr/libraries/Kaleidoscope-Plugin/tools//kaleidoscope-builder, add -ggdb3 to list of compiler options
new version of builder doesn't include prefs line, add something like this:
-prefs "compiler.cpp.extra_flags=${ARDUINO_CFLAGS} ${LOCAL_CFLAGS} -ggdb3" \
Then flash it
avrdude -c dragon_jtag -P usb -p atmega32u4 -v -U flash:w:./output/Model01-Firmware/Model01-Firmware-latest.hex
## connect avarice
This was the one that worked most reliably:
avarice -g :4242
This was causing issues after a while
avarice -g -P atmega32u4 --program --file output/Model01-Firmware/Model01-Firmware-latest.hex :4242 -r -R
## start gdb
avr-gdb ./output/Model01-Firmware/Model01-Firmware-latest.elf
target remote localhost:4242
continue
with 'set history save', can search back through history to do the connecting
then proceed as normal with gdb commands.
## add a breakpoint
b /home/matt/work/shortcut/raise-v3/firmwares/Kaleidoscope-test/hardware/keyboardio/avr/libraries/KeyboardioScanner/KeyboardioScanner.cpp:173
## bugs
often doesn't work - mostly fixed with the simpler avarice connection (and
possibly fuse change - not validated yet).
* try unplugging/replugging
* try reflash, with avrdude not avarice (verify flag on avarice always fails)
* try this avarice: avarice -g -B 2MHz --capture :4242
* make sure is running before attaching avraice and remove -R reset flag
* after connect with gdb, try continue and check program is still running
Also
* confusing with etags taking me to other definitions of functions but not the
ones actually used in the compliation.