Build KernelSU as LKM (#1254)

Co-authored-by: weishu <twsxtd@gmail.com>

userspace/ksud/src/assets.rs

@@ -1,29 +1,38 @@
 use anyhow::Result;
 use const_format::concatcp;
 use rust_embed::RustEmbed;
+use std::path::Path;
 
 use crate::{defs::BINARY_DIR, utils};
 
 pub const RESETPROP_PATH: &str = concatcp!(BINARY_DIR, "resetprop");
 pub const BUSYBOX_PATH: &str = concatcp!(BINARY_DIR, "busybox");
+pub const BOOTCTL_PATH: &str = concatcp!(BINARY_DIR, "bootctl");
 
-#[cfg(target_arch = "aarch64")]
-#[derive(RustEmbed)]
-#[folder = "bin/aarch64"]
-struct Asset;
-
-#[cfg(target_arch = "x86_64")]
+#[cfg(all(target_arch = "x86_64", target_os = "android"))]
 #[derive(RustEmbed)]
 #[folder = "bin/x86_64"]
 struct Asset;
 
+// IF NOT x86_64 ANDROID, ie. macos, linux, windows, always use aarch64
+#[cfg(not(all(target_arch = "x86_64", target_os = "android")))]
+#[derive(RustEmbed)]
+#[folder = "bin/aarch64"]
+struct Asset;
+
 pub fn ensure_binaries(ignore_if_exist: bool) -> Result<()> {
     for file in Asset::iter() {
-        utils::ensure_binary(
-            format!("{BINARY_DIR}{file}"),
-            &Asset::get(&file).unwrap().data,
-            ignore_if_exist,
-        )?
+        if file == "ksuinit" {
+            continue;
+        }
+        let asset = Asset::get(&file).ok_or(anyhow::anyhow!("asset not found: {}", file))?;
+        utils::ensure_binary(format!("{BINARY_DIR}{file}"), &asset.data, ignore_if_exist)?
     }
     Ok(())
 }
+
+pub fn copy_assets_to_file(name: &str, dst: impl AsRef<Path>) -> Result<()> {
+    let asset = Asset::get(name).ok_or(anyhow::anyhow!("asset not found: {}", name))?;
+    std::fs::write(dst, asset.data)?;
+    Ok(())
+}