IQ9 EVK as a Local Arm Build & Debug Machine for Mainline Linux Kernel

Dragonwing · Qualcomm

Introduction

The IQ9 EVK packs 8 Cortex-A78 cores at 1.9 GHz, 12 GB RAM, and 110 GB storage — powered by a single USB-C cable and easy to carry around. I was short of a local ARM build machine, and the IQ9 EVK was right there. So why not? This blog covers two things:

Local ARM build — using the IQ9 EVK itself as the ARM native build machine for mainline kernel
Mainline kernel debugging — more importantly, the board runs what it builds, making it a self-contained platform for mainline kernel bring-up and debugging

1. Local ARM Build on IQ9 EVK

The IQ9 EVK ships with Qualcomm Linux (QLI 2.0) — a Yocto-based image designed for running prebuilt apps. It’s locked down by design: no apt-get, no opkg.

$ cat /etc/issue
Qualcomm Linux Reference Distro (OTA-enabled) 2.0 \n \l

$ apt-get update
sh: apt-get: command not found

$ opkg --version
sh: opkg: command not found

To get a proper build environment, flash Ubuntu using Flash Using Qualcomm Launcher

$ cat /etc/issue
Ubuntu 24.04.4 LTS \n \l

Install build dependencies:

sudo apt update && sudo apt upgrade -y

sudo apt install -y \
    flex bison bc \
    build-essential \
    libssl-dev libelf-dev \
    libncurses-dev \
    git make gcc \
    kmod cpio rsync \
    python3 perl

Clone and build mainline kernel natively on the board:

git clone -b main https://github.com/qualcomm-linux/kernel-topics.git
make defconfig
make -j8

With 8 cores and 12 GB RAM, the build runs comfortably on the board itself — no cross-compilation needed.

2. Mainline Kernel Debugging on IQ9 EVK

We only have one IQ9 EVK — no backup machine, no second board. The goal: debug mainline kernel without bricking the board, with a clean fallback to the release Ubuntu image.

What we tried (and why it didn’t work)

a. kexec — the IQ9 watchdog kicks in and forces a reboot before the debug kernel can fully boot. b. fastboot boot — not supported on IQ9 yet, and requires a separate host machine anyway. c. GRUB menu with concatenated kernel + DTB — DTB couldn’t be passed through correctly this way. Add a new GRUB entry pointing to the debug kernel and DTB:

# refer to /boot/grub/grub.cfg for the template
sudo vi /etc/grub.d/40_custom

menuentry 'Ubuntu_debug' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-debug' {
        recordfail
        load_video
        gfxmode $linux_gfx_mode
        insmod gzio
        if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
        insmod part_gpt
        insmod ext2
        set root='hd0,gpt3'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt3 --hint-efi=hd0,gpt3 --hint-baremetal=ahci0,gpt3  c5de3ef5-e2b1-47ae-a2eb-34267d2d1441
        else
          search --no-floppy --fs-uuid --set=root c5de3ef5-e2b1-47ae-a2eb-34267d2d1441
        fi
        linux   /boot/Image dtb=/lemans-evk.dtb root=UUID=c5de3ef5-e2b1-47ae-a2eb-34267d2d1441 ro console=ttyMSM0,115200n8 pcie_pme=nomsi earlycon video=LVDS-1:d
        initrd  /boot/initramfs.cpio.gz
}

sudo update-grub

Deploy the build artifacts:

cd kernel-nord
# initramfs.cpio.gz must include the compiled kernel modules for this kernel build
sudo cp initramfs.cpio.gz /boot/
sudo cp arch/arm64/boot/dts/qcom/lemans-evk.dtb /boot/efi/
sudo cp arch/arm64/boot/Image /boot/

sudo reboot

At boot, when the console shows:

The highlighted entry will be executed automatically in 3s.

Select *Ubuntu_debug to boot into the mainline kernel.

Verify

$ uname -a
Linux qcom-armv8a 7.2.0-rc5-gf5098b6bae76 #1 SMP PREEMPT Fri Jul 31 07:31:15 UTC 2026 aarch64 GNU/Linux

$ mount /dev/sda3 /mnt
[   46.588831] EXT4-fs (sda3): mounted filesystem c5de3ef5-e2b1-47ae-a2eb-34267d2d1441 r/w with ordered data mode.

$ ls /mnt/home/ubuntu/
kernel-nord

Mainline kernel 7.2-rc5 is up and running. The release Ubuntu entry remains intact in GRUB — if anything goes wrong, just reboot and select the default entry. No bricks. 🎉 On the next reboot, GRUB defaults back to the release Ubuntu image automatically — no manual intervention needed. This gives us a safe, repeatable loop:

Boot into Ubuntu_debug to test mainline kernel
Reboot → back to stable release automatically
Iterate, fix, repeat

This workflow makes it straightforward to debug the latest mainline kernel and send patches. For example, one of the first things I caught: reboot doesn’t work on mainline kernel for IQ9 — a quick find, thanks to a clean and low-risk debug environment. Enjoy! 🚀

Tutorials

IQ9 EVK as a Local Arm Build & Debug Machine for Mainline Linux Kernel

Introduction

1. Local ARM Build on IQ9 EVK

2. Mainline Kernel Debugging on IQ9 EVK

What we tried (and why it didn’t work)

What worked: custom GRUB menu entry

Verify

Tutorials

​Introduction

​1. Local ARM Build on IQ9 EVK

​2. Mainline Kernel Debugging on IQ9 EVK

​What we tried (and why it didn’t work)

​What worked: custom GRUB menu entry

​Verify

Introduction

1. Local ARM Build on IQ9 EVK

2. Mainline Kernel Debugging on IQ9 EVK

What we tried (and why it didn’t work)

What worked: custom GRUB menu entry

Verify