I have been trying for a few days now. My final goal is to be able to load a kernel module (for example, a simple 'hello world' module) on a rooted Pixel 8 device running CalyxOS. For now, it will also be great to load it on a regular, vanilla, Google Pixel8, Android OS.

I followed the intructions on / except for the last "m" command. That is, I used the repo utility as described and used the setup scripts for Pixel 8 (codename shiba).

Afterwards, I created a simple C file for the module, named hello.c, and a Makefile as follows:

hello.c:

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>

MODULE_LICENSE("GPL");

static int __init module_start(void)
{
    printk(KERN_INFO "Hello, World!\n");
    return 0;
}

static void __exit module_end(void)
{
    printk(KERN_INFO "Goodbye, World!\n");
}

module_init(module_start);
module_exit(module_end);

Makefile:

obj-m += hello.o

all:
        make -C  ~/calyxos/android14/build M=$(PWD) modules
clean:
         make -C  ~/calyxos/android14/build M=$(PWD) clean

And then executed:

make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -C ~/calyxos/android14/build M=$(PWD) modules

I get an error from the make stating that there is no rule named "modules". Which is indeed correct, as there is no Makefile there at ~/calyxos/android14/build. I tried using the vanilla AOSP and got the same make error. I would appriciate any help on solving this issue.

Alternatively (and even better), I think that if somehow I'll get the kernel headers for the Android kernel version I want, I can to compile the module without compiling the kernel, but I fail to find a wat to retrieve it.

Note that I checked and I succefully can load a simple 'hello world' kernel module on a regular Linux machine (unrelated to the Pixel 8 device).