From ededdb2ed9d3c9749a8576faa8d0ca94825fbac6 Mon Sep 17 00:00:00 2001
From: Gabriel Kaszewski <gabrielkaszewski@gmail.com>
Date: Sun, 18 Oct 2026 02:19:30 +0200
Subject: [PATCH] refactor(userspace): split syscall stubs into arch-agnostic
 API + arch/riscv backend

---
 crates/userspace/src/arch/mod.rs   | 14 +++++
 crates/userspace/src/arch/riscv.rs | 75 ++++++++++++++++++++++++++
 crates/userspace/src/lib.rs        |  1 +
 crates/userspace/src/syscall.rs    | 85 ++++--------------------------
 4 files changed, 100 insertions(+), 75 deletions(-)
 create mode 100644 crates/userspace/src/arch/mod.rs
 create mode 100644 crates/userspace/src/arch/riscv.rs

diff --git a/crates/userspace/src/arch/mod.rs b/crates/userspace/src/arch/mod.rs
new file mode 100644
index 0000000..4f8d016
--- /dev/null
+++ b/crates/userspace/src/arch/mod.rs
@@ -0,0 +1,14 @@
+#[cfg(target_arch = "riscv64")]
+mod riscv;
+#[cfg(target_arch = "riscv64")]
+pub use riscv::*;
+
+#[cfg(target_arch = "aarch64")]
+mod arm;
+#[cfg(target_arch = "aarch64")]
+pub use arm::*;
+
+#[cfg(target_arch = "x86_64")]
+mod x86;
+#[cfg(target_arch = "x86_64")]
+pub use x86::*;
diff --git a/crates/userspace/src/arch/riscv.rs b/crates/userspace/src/arch/riscv.rs
new file mode 100644
index 0000000..2622fcc
--- /dev/null
+++ b/crates/userspace/src/arch/riscv.rs
@@ -0,0 +1,75 @@
+#[inline(always)]
+pub fn syscall0(nr: usize) -> usize {
+    let ret: usize;
+    unsafe {
+        core::arch::asm!(
+            "ecall",
+            in("a7") nr,
+            lateout("a0") ret,
+        );
+    }
+    ret
+}
+
+#[inline(always)]
+pub fn syscall1(nr: usize, a0: usize) -> usize {
+    let ret: usize;
+    unsafe {
+        core::arch::asm!(
+            "ecall",
+            in("a7") nr,
+            inlateout("a0") a0 => ret,
+        );
+    }
+    ret
+}
+
+#[inline(always)]
+pub fn syscall2(nr: usize, a0: usize, a1: usize) -> usize {
+    let ret: usize;
+    unsafe {
+        core::arch::asm!(
+            "ecall",
+            in("a7") nr,
+            inlateout("a0") a0 => ret,
+            in("a1") a1,
+        );
+    }
+    ret
+}
+
+#[inline(always)]
+pub fn syscall5(nr: usize, a0: usize, a1: usize, a2: usize, a3: usize, a4: usize) -> usize {
+    let ret: usize;
+    unsafe {
+        core::arch::asm!(
+            "ecall",
+            in("a7") nr,
+            inlateout("a0") a0 => ret,
+            in("a1") a1,
+            in("a2") a2,
+            in("a3") a3,
+            in("a4") a4,
+        );
+    }
+    ret
+}
+
+#[inline(always)]
+pub fn syscall_receive(nr: usize, a0: usize) -> (usize, usize, usize, usize) {
+    let r0: usize;
+    let r1: usize;
+    let r2: usize;
+    let r3: usize;
+    unsafe {
+        core::arch::asm!(
+            "ecall",
+            in("a7") nr,
+            inlateout("a0") a0 => r0,
+            lateout("a1") r1,
+            lateout("a2") r2,
+            lateout("a3") r3,
+        );
+    }
+    (r0, r1, r2, r3)
+}
diff --git a/crates/userspace/src/lib.rs b/crates/userspace/src/lib.rs
index 7b3b5ed..90edb3e 100644
--- a/crates/userspace/src/lib.rs
+++ b/crates/userspace/src/lib.rs
@@ -1,3 +1,4 @@
 #![no_std]
 
+mod arch;
 pub mod syscall;
diff --git a/crates/userspace/src/syscall.rs b/crates/userspace/src/syscall.rs
index e135e96..056f0ed 100644
--- a/crates/userspace/src/syscall.rs
+++ b/crates/userspace/src/syscall.rs
@@ -1,105 +1,40 @@
+use crate::arch;
 use types::syscall_abi::*;
 
-#[inline(always)]
-fn ecall0(nr: usize) -> usize {
-    let ret: usize;
-    unsafe {
-        core::arch::asm!(
-            "ecall",
-            in("a7") nr,
-            lateout("a0") ret,
-        );
-    }
-    ret
-}
-
-#[inline(always)]
-fn ecall1(nr: usize, a0: usize) -> usize {
-    let ret: usize;
-    unsafe {
-        core::arch::asm!(
-            "ecall",
-            in("a7") nr,
-            inlateout("a0") a0 => ret,
-        );
-    }
-    ret
-}
-
-#[inline(always)]
-fn ecall2(nr: usize, a0: usize, a1: usize) -> usize {
-    let ret: usize;
-    unsafe {
-        core::arch::asm!(
-            "ecall",
-            in("a7") nr,
-            inlateout("a0") a0 => ret,
-            in("a1") a1,
-        );
-    }
-    ret
-}
-
 pub fn exit() -> ! {
-    ecall0(SYS_EXIT);
+    arch::syscall0(SYS_EXIT);
     loop {}
 }
 
 pub fn exit_thread() -> ! {
-    ecall0(SYS_EXIT_THREAD);
+    arch::syscall0(SYS_EXIT_THREAD);
     loop {}
 }
 
 pub fn yield_now() {
-    ecall0(SYS_YIELD);
+    arch::syscall0(SYS_YIELD);
 }
 
 pub fn get_time() -> usize {
-    ecall0(SYS_GET_TIME)
+    arch::syscall0(SYS_GET_TIME)
 }
 
 pub fn get_process_id() -> usize {
-    ecall0(SYS_GET_PROCESS_ID)
+    arch::syscall0(SYS_GET_PROCESS_ID)
 }
 
 pub fn spawn_thread(entry: usize, stack: usize) -> usize {
-    ecall2(SYS_SPAWN_THREAD, entry, stack)
+    arch::syscall2(SYS_SPAWN_THREAD, entry, stack)
 }
 
 pub fn request_pages(count: usize) -> usize {
-    ecall1(SYS_REQUEST_PAGES, count)
+    arch::syscall1(SYS_REQUEST_PAGES, count)
 }
 
 pub fn send(endpoint: usize, w0: usize, w1: usize, w2: usize, w3: usize) -> usize {
-    let ret: usize;
-    unsafe {
-        core::arch::asm!(
-            "ecall",
-            in("a7") SYS_SEND,
-            inlateout("a0") endpoint => ret,
-            in("a1") w0,
-            in("a2") w1,
-            in("a3") w2,
-            in("a4") w3,
-        );
-    }
-    ret
+    arch::syscall5(SYS_SEND, endpoint, w0, w1, w2, w3)
 }
 
 pub fn receive(endpoint: usize) -> (usize, usize, usize, usize) {
-    let r0: usize;
-    let r1: usize;
-    let r2: usize;
-    let r3: usize;
-    unsafe {
-        core::arch::asm!(
-            "ecall",
-            in("a7") SYS_RECEIVE,
-            inlateout("a0") endpoint => r0,
-            lateout("a1") r1,
-            lateout("a2") r2,
-            lateout("a3") r3,
-        );
-    }
-    (r0, r1, r2, r3)
+    arch::syscall_receive(SYS_RECEIVE, endpoint)
 }