Login

Become a leader in the IoT community!

Join our community of embedded and IoT practitioners to contribute experience, learn new skills and collaborate with other developers with complementary skillsets.

Step 1 of 5

CREATE YOUR PROFILE *Required

Step 2 of 5

WHAT BRINGS YOU TO DEVHEADS? *Choose 1 or more

Connect & collaborate 🤝with other tech professionals

I want to connect & collaborate with other techies

Learn & Grow 📚

Learn from our helpers & grow your tech knowledge

Contribute Experience & Expertise 🔧

Become a helpful hacker & assist others by sharing

Step 3 of 5

WHAT'S YOUR INTEREST OR EXPERTISE? *Choose 1 or more

Hardware Design 💡

PCB design, analog circuits, and more.

Embedded Software 💻

Embedded OS, firmware/middleware, debug & tools

Edge Networking ⚡

Real-time/low-power connectivity & IoT device management

Step 4 of 5

Personalize your profile

Step 5 of 5

Read & agree to our COMMUNITY RULES

We want this server to be a welcoming space! Treat everyone with respect. Absolutely no harassment, witch hunting, sexism, racism, or hate speech will be tolerated.
If you see something against the rules or something that makes you feel unsafe, let staff know by messaging @admin in the "support-tickets" tab in the Live DevChat menu.
No age-restricted, obscene or NSFW content. This includes text, images, or links featuring nudity, sex, hard violence, or other graphically disturbing content.
No spam. This includes DMing fellow members.
You must be over the age of 18 years old to participate in our community.
You agree to our Terms of Service (https://www.devheads.io/terms-of-service/) and Privacy Policy (https://www.devheads.io/privacy-policy)

By clicking "Finish", you have read and agreed to the our Terms of Service and Privacy Policy.

How to Disassemble and Filter Out Static Jumps in Program Output with Bash

Posted by Marvee Amasi
11:53 am
21/11/2024

My program outputs encoded instructions, and each line represents an independent set of instructions, like this:

0x81FB4300000090
0x69FC4300000090
0x81FC4300000090
0x69FD4300000090
0x81FD4300000090
0x69FE4300000090
0x81FE4300000090
0x69FF4300000090
0x81FF4300000090
0x00054400000090
0x01054400000090
0x02054400000090
0x03054400000090
0x08054400000090
0x09054400000090
0x0A054400000090
0x0B054400000090
0x10054400000090
0x11054400000090
0x12054400000090
0x13054400000090
0x18054400000090
0x19054400000090
0x1A054400000090
0x1B054400000090
0x20054400000090
0x21054400000090
0x22054400000090
0x23054400000090
0x28054400000090
0x29054400000090
0x2A054400000090
0x2B054400000090
0x30054400000090
0x31054400000090
0x32054400000090
0x33054400000090
0x38054400000090
0x39054400000090
0x3A054400000090
0x3B054400000090
0x40054400000090
0x41054400000090
0x42054400000090
0x43054400000090
0x44054400000090
0x45054400000090
0x46054400000090
0x47054400000090

So each line consists of 7 bytes of encoded instructions, and I need to disassemble each of them separately as distinct programs. I can also output the binary directly, and in that case, each 7 byte block of instructions must be disassembled individually.

In the bash script that runs my program, I want to filter out lines that contain static jumps. I want to:
1. Disassemble each instruction set from the program output.
2. Use a command like `grep` to filter out lines containing certain instructions, like `loopne`.

I tried using `objdump`, but it doesn’t accept `/dev/stdin` as an input file.
How can I disassemble each line of 7 byte instructions separately from `stdin` and filter out the ones containing static jumps ?