id = 1251
title = "Octeon Instruction BBIT Bug"
state = "closed"
created_at = "2022-10-12T05:01:21.815Z"
closed_at = "2022-12-07T16:08:30.602Z"
labels = ["target: mips"]
url = "https://gitlab.com/qemu-project/qemu/-/issues/1251"
host-os = "All"
host-arch = "All"
qemu-version = "7.1.50"
guest-os = "Userspace"
guest-arch = "mips64"
description = "n/a"
reproduce = """1. Compile 64bit binary for Octeon with Octeon instructions    
`mips64-octeon-linux-gnu-gcc -o hello hello.c`
2. Run with `qemu-mips64`    
`qemu-mips64 -cpu Octeon68XX hello`
3. Get the output below:
```
qemu: uncaught target signal 4 (Illegal instruction) - core dumped
Illegal instruction
```"""
additional = """I have a patch for this that I will be submitting to trivial-patches. This is not enough to emulate Octeon specific binaries alone. For small binaries mapping the `CVMSEG_LM = 0xFFFFFFFFFFFF8000 - 0xFFFFFFFFFFFF9FFF` to empty RAM and using this patch is enough. There are additional support issues for `N32` binaries that will require a separate issue.

[hello](/uploads/d8b5e631508fd232b4a7b3a40f7e08f6/hello)"""