cosim-gpu-disk-image-edit

name	cosim-gpu-disk-image-edit
description	Use when the guest disk image needs modification without a full rebuild. Mount with guestmount, add files, systemd services, kernel module config.

Cosim Disk Image Edit

Modify the cosim guest disk image without rebuilding.

Prerequisites

• QEMU must NOT be running (disk image cannot be mounted while in use)
• guestmount must be available (libguestfs-tools package)

pgrep -af 'qemu-system-x86_64|cosim_launch.sh|run_cosim_tests.sh' && echo "STOP COSIM FIRST" || echo "OK"
find /tmp -maxdepth 1 -type d -name '*qemu-cosim*.session' -print
which guestmount || echo "Install: apt install libguestfs-tools"

Disk image location

gem5-resources/src/x86-ubuntu-gpu-ml/disk-image/x86-ubuntu-rocm70

Format: raw, GPT, partition 1 is the root filesystem.

Mount

DISK="./gem5-resources/src/x86-ubuntu-gpu-ml/disk-image/x86-ubuntu-rocm70"
MOUNTPOINT="/tmp/cosim-disk"
mkdir -p "$MOUNTPOINT"
guestmount -a "$DISK" -m /dev/sda1 --rw "$MOUNTPOINT"

Edit scope

Supported edit classes:

• Add or replace files under the guest filesystem.
• Add or update systemd units and matching enablement symlinks.
• Add or update kernel module configuration under /etc/modprobe.d/.
• Install ROCm runtime debug components through repository scripts when the task is runtime debugging.
• Inspect disk layout with fdisk -l "$DISK" if guestmount cannot find /dev/sda1.

Keep the concrete file contents in the task artifact or source patch. Do not embed large service templates or generated scripts in the skill itself.

Unmount

Always unmount before starting QEMU:

guestunmount "$MOUNTPOINT"
sleep 2
ls "$MOUNTPOINT" 2>/dev/null && echo "Still mounted!" || echo "OK"

Notes

• guestmount uses FUSE — no sudo needed
• Changes write directly to raw image file
• Back up the disk image before risky changes (55 GB, consider snapshots)