Revert "support esp32 (#4)"

This reverts commit 201efd8.

Cargo.toml

@@ -12,13 +12,9 @@ repository = "https://github.com/nickray/littlefs2-sys"
 [dependencies]
 cty = "0.2.1"
 
-[target.'cfg(target_os = "espidf")'.dependencies]
-esp-idf-sys = { version = "0.31" }
-
 [build-dependencies]
-bindgen = { version = "0.60", default-features = false, features = ["runtime"] }
+bindgen = { version = "0.60", default-features = false }
 cc = "1"
-embuild = { version = "0.30", features = ["espidf"] }
 
 [features]
 assertions = []

build.rs

@@ -1,4 +1,3 @@
-use embuild::cmd::Cmd;
 use std::env;
 use std::path::PathBuf;
 
@@ -13,7 +12,8 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         .flag("-DLFS_NO_ERROR")
         .file("littlefs/lfs.c")
         .file("littlefs/lfs_util.c")
-        .file("string.c");
+        .file("string.c")
+    ;
 
     #[cfg(not(feature = "assertions"))]
     let builder = builder.flag("-DLFS_NO_ASSERT");
@@ -23,29 +23,14 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     builder.compile("lfs-sys");
 
-    let mut builder = bindgen::Builder::default()
+    let bindings = bindgen::Builder::default()
         .header("littlefs/lfs.h")
         .clang_arg(format!("--target={}", target))
         .use_core()
         .ctypes_prefix("cty")
-        .rustfmt_bindings(true);
-
-    let target = env::var("TARGET").unwrap();
-
-    if target == "xtensa-esp32s3-espidf" {
-        let mut cmd = Cmd::new("xtensa-esp32s3-elf-ld");
-        cmd.arg("--print-sysroot");
-        let sysroot = cmd
-            .stdout()
-            .map(PathBuf::from)
-            .expect("Failed to find sysroot");
-
-        builder = builder.clang_arg(format!("--sysroot={}", sysroot.display()));
-        // TODO: determine why it isn't sufficient to just set the sysroot.
-        builder = builder.clang_arg(format!("-I{}", sysroot.join("include").display()))
-    }
-
-    let bindings = builder.generate().expect("Unable to generate bindings");
+        .rustfmt_bindings(true)
+        .generate()
+        .expect("Unable to generate bindings");
 
     let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
     bindings