Error encountered while trying to generating instruction traces using majordomo

[dragon540]

I need to generate instruction traces for the BPU testbench I am working on. For generating traces I am using majordomo (https://github.com/jeffnye-gh/majordomo?tab=readme-ov-file).

I have been able to build the repo, and pass all regressions. However when I try to run commands required to generate instruction traces from the elf file, I am constantly getting error: unexpected character. Following are step by step replication of commands I am using.

This is C file (ex.c) I am generating elf from

#include "../../riscv-perf-model/traces/stf_trace_gen/trace_macros.h"

int main() {
        START_TRACE;
        int x = 55;
        while(x<100) {
                x++;
        }
        x = x-9;
        x = x*9;
        STOP_TRACE;
        return 0;
}

Generating elf from c file

(sparta) shobhit@shobhit-i440FX-PIIX-1996:~/majordomo/build$ ../../Downloads/riscv-embecosm-embedded-ubuntu2204-20240407/bin/riscv64-unknown-elf-gcc ex.c -o ex.elf -O0

Command for generating trace from elf file

(sparta) shobhit@shobhit-i440FX-PIIX-1996:~/majordomo/build$ ./majordomo --march=rv64gc --stf_trace ex.zstf --stf_priv_modes USHM ex.elf

This gives me the following error - error: unexpected character

If anyone of you have tried majordomo before, can you take a look at this?

[klingaard]

Did you try building your test application statically?

riscv64-unknown-elf-gcc ex.c -o ex.elf -O0 -static

[dragon540]

I found what was generated by the embecosm compiler was a 32 bit ELF, could this be a possible source of error: unexpected character? I suspect this because I am already able to generate trace from the example elf (rvt_mm.bare.elf) given under the examples sub-directory of majordomo, and running file rvt_mm.bare.elf gives the following -
rvt_mm.bare.elf: ELF 64-bit LSB executable, UCB RISC-V, RVC, double-float ABI, version 1 (SYSV), statically linked, not stripped

Therefore I compiled ex.c statically to a 64 bit ELF using riscv-gnu-toolchain compiler, by running the following command - riscv64-unknown-elf-gcc ex.c -o ex.elf -O0 -static

Running the command to generate trace -

shobhit@shobhit-i440FX-PIIX-1996:~/majordomo/build$ ./majordomo --ctrlc --march=rv64gc --stf_trace ex.zstf --stf_priv_modes USHM ex.elf

Now gives -

majordomo: WARNING multiple bootrams; last winsmajordomo: WARNING multiple bootrams; last winsSimulation speed: 0.00 MIPS (single-core)

[jeffnye-gh]

First my apologies for just noticing this post. For specific questions about Majordomo it is more efficient to submit those directly to the majordomo issues/or discussions board.

Second: for use with Olympia, Majordomo, and Dromajo are deprecated, their ISA support is not current. See riscv-perf-model/traces/README.md for current instructions.

Addressing your question for future reference:

Your compile command is not correct, it is including the default gcc startup files. There are more details in the majordomo/examples directory, specifically how to compile for baremetal.

See the Majordomo/README.md

# Examples
The examples directory contains examples of how to build, run and trace baremetal applications. There is a quick sort example derived from riscv-tests/benchmarks.

Majordomo will remain, it's primary purpose has changed.