Compile successfully on i686 as well.

build.rs

@@ -4,7 +4,7 @@ use std::env;
 use std::path::Path;
 use std::process::Command;
 
-fn parse_kconfig(arch: &str) {
+fn parse_kconfig(arch: &str) -> Option<()> {
     println!("cargo:rerun-if-changed=config.toml");
 
     assert!(Path::new("config.toml.example").try_exists().unwrap());
@@ -13,9 +13,10 @@ fn parse_kconfig(arch: &str) {
     }
     let config_str = std::fs::read_to_string("config.toml").unwrap();
     let root: Table = toml::from_str(&config_str).unwrap();
-    let altfeatures = root.get("arch").unwrap().as_table().unwrap()
-        .get(arch).unwrap().as_table().unwrap()
-        .get("features").unwrap().as_table().unwrap();
+
+    let altfeatures = root.get("arch")?.as_table().unwrap()
+        .get(arch)?.as_table().unwrap()
+        .get("features")?.as_table().unwrap();
 
     for (name, value) in altfeatures {
         let choice = value.as_str().unwrap();
@@ -23,6 +24,8 @@ fn parse_kconfig(arch: &str) {
 
         println!("cargo:rustc-cfg=cpu_feature_{choice}=\"{name}\"");
     }
+
+    Some(())
 }
 
 fn main() {
@@ -72,5 +75,5 @@ fn main() {
         _ => (),
     }
 
-    parse_kconfig(arch_str);
+    let _ = parse_kconfig(arch_str);
 }

src/arch/x86/mod.rs

@@ -86,3 +86,9 @@ pub unsafe extern "fastcall" fn arch_copy_to_user_inner(len: usize, dst: usize,
 pub unsafe fn bootstrap_mem(bootstrap: &Bootstrap) -> &'static [u8] {
     core::slice::from_raw_parts(CurrentRmmArch::phys_to_virt(bootstrap.base.start_address()).data() as *const u8, bootstrap.page_count * PAGE_SIZE)
 }
+pub const KFX_SIZE: usize = 512;
+
+// This function exists as the KFX size is dynamic on x86_64.
+pub fn kfx_size() -> usize {
+    KFX_SIZE
+}

src/context/arch/x86.rs

@@ -20,7 +20,6 @@ pub static CONTEXT_SWITCH_LOCK: AtomicBool = AtomicBool::new(false);
 
 const ST_RESERVED: u128 = 0xFFFF_FFFF_FFFF_0000_0000_0000_0000_0000;
 
-pub const KFX_SIZE: usize = 512;
 pub const KFX_ALIGN: usize = 16;
 
 #[derive(Clone, Debug)]