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androidramdisk

missing ramdisk in boot.img for Android 13

I used magiskboot to unpack Android 13 pixel 6a boot.img to mess around with a ramdisk and init.

But when I unpacked it, it only gave kernel file, no ramdisk.

Why is that?

If I flash the stock boot.img, then how does it know what to load since there is no ramdisk?

Thanks

Solution

  • https://source.android.com/docs/core/architecture/partitions/generic-boot

    Android 12, the generic boot image, referred to as Generic Kernel Image (GKI), contains the generic ramdisk and the GKI kernel.

    For devices launching with Android 13, the generic ramdisk is removed from the boot image and placed in a separate init_boot image. This change leaves the boot image with only the GKI kernel.

    For upgrading devices that continue to use Android 12 or older kernel versions, the generic ramdisk remains where it was with no requirement for a new init_boot image.