`mkbootfs` command not found while trying to build AOSP kernel

Question

Followed guide here: https://source.android.com/setup/build/building-kernels

mkdir android-kernel && cd android-kernel
repo init -u https://android.googlesource.com/kernel/manifest -b android-msm-bonito-4.9-android11-qpr2
repo sync
build/build.sh

It runs for ~7min then fails @

Creating initramfs: build/build.sh: line 967: mkbootfs: command not found

I found the mkbootfs binary, in many locations actually, and all of them, when executed, say "command not found"!

• I tried chmod 777 & chmod +x, but same issue.
• Tried sudo as well.
• I tried adding $HOME/android/aosp-kernel/build/build-tools/path/linux-x86 to my PATH but same results.

build\build.sh Line 967 is not where the mkbootfs cmd is, but it does appear on line 980:

mkbootfs "${INITRAMFS_STAGING_DIR}" >"${MODULES_STAGING_DIR}/initramfs.cpio"

What is the expected result when mkbootfs is run without parameters??

I'd think this would be easy. For some reason, I can't find anything helpful on the net.

Please help.

Answer 1

Issue: Cloning the repo doesn't include these folders:

• /aosp-kernel/prebuilts/build-tools/path/linux-x86/
• /aosp-kernel/prebuilts/build-tools/path/linux-x86/bin
• /aosp-kernel/prebuilts/kernel-build-tools/linux-x86/bin/[mkbootfs] (& more)
• (maybe a few more)

Note: kernel-build-tools URL/Repo is on https://android.googlesource.com/kernel/prebuilts/build-tools/+/refs/heads/master/linux-x86/bin/

Band-aid Fix: (x86 Linux)

cd ~/
mkdir kernel-build-tools
git clone https://android.googlesource.com/kernel/prebuilts/build-tools
ls -l kernel-build-tools

Add build tools you just downloaded to the path: (this will work as the current user, NOT SUDO!)

nano ~/.profile

Paste the following lines at the end of your ~/.profile file.

# add Kernel tools to path
if [ -d "$HOME/kernel-build-tools/build-tools/linux-x86/bin" ] ; then
    PATH="$HOME/kernel-build-tools/build-tools/linux-x86/bin:$PATH"
fi

Refresh your shell environment: source ~/.profile

VALIDATE: mkbootfs -> "error: no directories to process?!" (This is good!)

I was able to compile it after this. FYI, ~/aosp-kernel/ is where I synced the Android kernel to.