From d3b3d5d462261606afd979fc909c0e3819417a6a Mon Sep 17 00:00:00 2001
From: David CARLIER <devnexen@gmail.com>
Date: Wed, 10 Apr 2024 00:01:27 +0100
Subject: [PATCH] bolts: add time ticks method for arm (#2032)

---
 libafl_bolts/src/cpu.rs | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/libafl_bolts/src/cpu.rs b/libafl_bolts/src/cpu.rs
index c8be696d02..d885d84ceb 100644
--- a/libafl_bolts/src/cpu.rs
+++ b/libafl_bolts/src/cpu.rs
@@ -1,12 +1,13 @@
 //! Architecture agnostic processor features
 
-#[cfg(target_arch = "aarch64")]
+#[cfg(any(target_arch = "aarch64", target_arch = "arm"))]
 use core::arch::asm;
 
 #[cfg(not(any(
     target_arch = "x86_64",
     target_arch = "x86",
     target_arch = "aarch64",
+    target_arch = "arm",
     target_arch = "riscv64",
     target_arsch = "riscv32"
 )))]
@@ -50,6 +51,16 @@ pub fn read_time_counter() -> u64 {
     v
 }
 
+#[cfg(target_arch = "arm")]
+#[must_use]
+pub fn read_time_counter() -> u64 {
+    let mut v: u32;
+    unsafe {
+        asm!("mrc p15, 0, {v}, c9, c13, 0", v = out(reg) v);
+    }
+    u64::from(v)
+}
+
 /// Read a timestamp for measurements
 ///
 /// Fetches the full 64 bits of the cycle counter in one instruction.
@@ -99,6 +110,7 @@ pub fn read_time_counter() -> u64 {
     target_arch = "x86_64",
     target_arch = "x86",
     target_arch = "aarch64",
+    target_arch = "arm",
     target_arch = "riscv64",
     target_arch = "riscv32"
 )))]