25.3. rvbacktrace_RTThread

25.3.1. Overview

This example demonstrates the stack backtracking of threads in RTThread-nano on a riscv32 machine by using the frame pointer.

25.3.2. Hardware Configuration

No special configuration is required.

25.3.3. Running the example

Once this program runs correctly, the thread stack information of the corresponding thread will be output on the console. Entering rv_backtrace_all in finsh will output the information of the thread stacks of other threads except the current thread.

single thread

initialize rti_board_start:0 done

\ | /
- RT -     Thread Operating System
/ | \     3.1.5 build Nov 20 2024
2006 - 2020 Copyright by rt-thread team
do components initialization.
initialize rti_board_end:0 done
initialize finsh_system_init:0 done

---- RV_Backtrace Call Frame Start: ----
###Please consider the value of ra as accurate and the value of sp as only for reference###
----------s--------------------Thread: main backtrace------------------------------
Current Thread Name:  main
[0]Stack interval :[0x10819a0 - 0x10819c0]  ra 0x800103ea
[1]Stack interval :[0x10819c0 - 0x10819d0]  ra 0x8000ff9c
[2]Stack interval :[0x10819d0 - 0x10819e0]  ra 0x80006708
[3]Stack interval :[0x10819e0 - 0x1081a00]  ra 0x800094f6
[4]Stack interval :[0x1081a00 - 0xdeadbeef]  ra 0x8000c65a

addr2line -e xxx.elf -a -f 800103e6 8000ff98 80006704 800094f2 8000c656
---- RV_Backtrace Call Frame End:----

threads

rv_backtrace_all

---- RV_Backtrace Call Frame Start: ----
------------------------------Thread: event_send backtrace------------------------------
[0]Thread Name:  event_send
[0]Stack interval :[0x108299c - 0x10829cc]  ra 0x8000cb7a
[1]Stack interval :[0x10829cc - 0x10829fc]  ra 0x8000cbdc
[2]Stack interval :[0x10829fc - 0x1082a1c]  ra 0x8000667c
[3]Stack interval :[0x1082a1c - 0xdeadbeef]  ra 0x8000c65a

addr2line -e xxx.elf -a -f 8000cb76 8000cbd8 80006678 8000c656
------------------------------Thread: event_rec backtrace------------------------------
[1]Thread Name:  event_rec
[0]Stack interval :[0x1082504 - 0x1082544]  ra 0x8000a0a6
[1]Stack interval :[0x1082544 - 0x1082574]  ra 0x8000663e
[2]Stack interval :[0x1082574 - 0xdeadbeef]  ra 0x8000c65a

addr2line -e xxx.elf -a -f 8000a0a2 8000663a 8000c656
------------------------------Thread: tidle backtrace------------------------------
[3]Thread Name:  tidle
[0]Stack interval :[0x10804e0 - 0x1080510]  ra 0x800096ee
[1]Stack interval :[0x1080510 - 0xdeadbeef]  ra 0x8000c65a

addr2line -e xxx.elf -a -f 800096ea 8000c656
------------------------------Thread: timer backtrace------------------------------
[4]Thread Name:  timer
[0]Stack interval :[0x1080928 - 0x1080958]  ra 0x8000d8d6
[1]Stack interval :[0x1080958 - 0xdeadbeef]  ra 0x8000c65a

addr2line -e xxx.elf -a -f 8000d8d2 8000c656
Thread Total Num: 5
---- RV_Backtrace Call Frame End:----

25.3.4. note

Enabling BACKTRACE_ALL in the backtrace_config.h file allows for the backtracking of all thread stacks except the current one.
To view the call chain of function names, the addr2line tool needs to be used
```
addr2line -e xxx.elf -a -f <addr1> <addr2> ...
```
This component is generally used for software debugging. It is recommended to use it under the debug level.