From 4f1920ab96ece66c104497a8d2ddffce3fcf58c8 Mon Sep 17 00:00:00 2001
From: Anhad Singh <andypython@protonmail.com>
Date: Mon, 1 Dec 2025 14:35:10 +1100
Subject: [PATCH] feat(ld_so/tcb): implement `os_arch_activate` for aarch64
 linux

Signed-off-by: Anhad Singh <andypython@protonmail.com>
---
 src/ld_so/tcb.rs | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/ld_so/tcb.rs b/src/ld_so/tcb.rs
index 6dbf4cbb39..2375ce1228 100644
--- a/src/ld_so/tcb.rs
+++ b/src/ld_so/tcb.rs
@@ -343,6 +343,19 @@ impl Tcb {
         }
     }
 
+    #[cfg(all(target_os = "linux", target_arch = "aarch64"))]
+    unsafe fn os_arch_activate(_os: &(), tls_end: usize, tls_len: usize) {
+        // Uses ABI page
+        let abi_ptr = tls_end - tls_len - 16;
+        unsafe {
+            core::ptr::write(abi_ptr as *mut usize, tls_end);
+            core::arch::asm!(
+                "msr tpidr_el0, {}",
+                in(reg) abi_ptr,
+            );
+        }
+    }
+
     #[cfg(target_os = "redox")]
     unsafe fn os_arch_activate(
         os: &OsSpecific,