Live-coding Raspberry Pi Pico Emulator (Episode 9)
This week we'll hack on the gdbserver and then use it to diagnose the failing assertion in the Pico's startup code.
In this live-coding series we're implementing an emulator for the RP2040 chip, which powers the new Raspberry Pi Pico. Every week we implement a new feature together, diving into the datasheet and thickening our Cortex M0 implementation.
Previous streams: • Live Coding RP2040 Emulator
Get weekly updates about the streams: https://pages.wokwi.com/rp2040
For more details check out the Hackaday project: https://hackaday.io/project/177082-ra...
Project repo: https://github.com/wokwi/rp2040js
Wokwi Arduino simulator: https://wokwi.com
00:00 Getting started + Recap
1:38 ASRS, EORS, SXTB: reviewing Pull request from BrianPopeck 👍
15:10 Bug in signExtend8() and signExtend16()
21:56 Hacking on gdbserver
30:23 Digging into the GDB protocol
41:15 GDB 'M' - write memory
46:00 GDB 'c' - continue + execute() and stop() methods
56:17 Stepping/breakpoints don't work! 😒
1:05:40 Fixing Flash/bootrom memory writes
1:14:45 Forcing Thumb mod?
1:29:27 Comparing with the physical Pi Pico
1:33:57 GDB vCont command
1:42:12 stepi works! 🎉
1:46:47 UDF (undefined instruction) for GDB breakpoints
1:50:25 Branch decoding fix + PC after break
2:00:02 Breakpoints work! Great success 🥳
2:08:35 GDB 'P' - write register command
2:18:45 Setting up GDB debugging in Visual Studio Code
2:31:50 What's next?