It is never nice when a project coredumps. With this tool. you might be able to figure out why it coredumps and what you can do about it.
Note that some coredumps are not caused by the Python or C code, but by instability of the microcontroller. For example, supplying not enough power or … will also generate a coredump.
Install the ESP-IDF toolchain. You can find instructions here. If you already built our firmware from source once, you do not need to install the idf again.
This will provide us with a tool called addr2line, which converts the stacktrace addresses to a line number in C sourcecode. From here, we might be able to determine the root cause of the coredump. You can find the tool in ../xtensa-esp32-elf/bin/xtensa-esp32-elf-addr2line.
Note: This is a command line tool only.
Grab the .elf for your firmware version and board type here. From here on, we will call it application.elf
If you do not know your current firmware version, you can check it using:
>>> import os >>> os.uname()
Wait for your running code to coredump. I attached an example here. We are only interested in the top section.
Guru Meditation Error: Core 0 panic'ed (StoreProhibited). Exception was unhandled.
Core 0 register dump:
PC : 0x40195846 PS : 0x00060530 A0 : 0x801952fb A1 : 0x3ffbaef0
A2 : 0x00000000 A3 : 0x00000000 A4 : 0x00000005 A5 : 0xffffffff
A6 : 0x0000336d A7 : 0x3ffba1c4 A8 : 0x80194d84 A9 : 0x3ffbaeb0
A10 : 0x00000028 A11 : 0x00000000 A12 : 0x3ffb9f28 A13 : 0x00000000
A14 : 0x3ffb9f38 A15 : 0x00000001 SAR : 0x00000000 EXCCAUSE: 0x0000001d
EXCVADDR: 0x0000002d LBEG : 0x40093718 LEND : 0x40093746 LCOUNT : 0xffffffff
ELF file SHA256: 0000000000000000000000000000000000000000000000000000000000000000
Backtrace: 0x40195846:0x3ffbaef0 0x401952f8:0x3ffbaf10 0x40184fe8:0x3ffbaf30
================= CORE DUMP START =================
hDEAAAEAAAAOAAAAbAEAAA==
tJ/7PzCu+z/Er/s/
0K37P2Cv+z/MMwAAEMj8PxDI/D+0n/s/CMj8PwcAAAAIn/s/CJ/7P7Sf+z8AAAAA
EgAAAMih+z90aVQA6MX8P7x9+z/EffsAAAAAAMSv+z8AAAAAIAcGABIAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAADUZPs/PGX7P6Rl+z8AAAAAAAAAAAEAAAAAAAAA
OsRAPwAAAAAoUAlAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
...
Navigate terminal to the folder where your application.elf file is located. From there, use the following command. replace [backtrace] with the numbers following the Backtrace: in the coredump.
xtensa-esp32-elf-addr2line -fe [application.elf] [backtrace]
In this case, the backtrace is
0x40195846:0x3ffbaef0 0x401952f8:0x3ffbaf10 0x40184fe8:0x3ffbaf30
The output of this command will give you the files and line numbers of the last ran commands (stack trace), where the last command will have caused the error.
More Advanced
You can also use thextensa-esp32-elf-gdbtool in the command line, which will return where in the code the processor crashed. You can use:
info symbol [PC](where[PC]is the program counter found in the coredump) to get the section of the line that causes the coredumpdisassemble [PC]to get the instructions of the specified line in assemble format.
