diff --git a/cortex-a-rt/src/lib.rs b/cortex-a-rt/src/lib.rs
index c084f1e..304ccbf 100644
--- a/cortex-a-rt/src/lib.rs
+++ b/cortex-a-rt/src/lib.rs
@@ -708,6 +708,20 @@ core::arch::global_asm!(
         stm     r0!, {{r3}}
         b       0b
     1:
+        // Zero all registers before calling kmain
+        mov     r0, 0
+        mov     r1, 0
+        mov     r2, 0
+        mov     r3, 0
+        mov     r4, 0
+        mov     r5, 0
+        mov     r6, 0
+        mov     r7, 0
+        mov     r8, 0
+        mov     r9, 0
+        mov     r10, 0
+        mov     r11, 0
+        mov     r12, 0
         // Jump to application
         bl      kmain
         // In case the application returns, loop forever
diff --git a/cortex-r-rt/src/lib.rs b/cortex-r-rt/src/lib.rs
index b064856..052412f 100644
--- a/cortex-r-rt/src/lib.rs
+++ b/cortex-r-rt/src/lib.rs
@@ -742,6 +742,20 @@ core::arch::global_asm!(
         "#,
     fpu_enable!(),
     r#"
+        // Zero all registers before calling kmain
+        mov     r0, 0
+        mov     r1, 0
+        mov     r2, 0
+        mov     r3, 0
+        mov     r4, 0
+        mov     r5, 0
+        mov     r6, 0
+        mov     r7, 0
+        mov     r8, 0
+        mov     r9, 0
+        mov     r10, 0
+        mov     r11, 0
+        mov     r12, 0
         // Jump to application
         bl      kmain
         // In case the application returns, loop forever
@@ -805,6 +819,20 @@ core::arch::global_asm!(
         "#,
         fpu_enable!(),
         r#"
+        // Zero all registers before calling kmain
+        mov     r0, 0
+        mov     r1, 0
+        mov     r2, 0
+        mov     r3, 0
+        mov     r4, 0
+        mov     r5, 0
+        mov     r6, 0
+        mov     r7, 0
+        mov     r8, 0
+        mov     r9, 0
+        mov     r10, 0
+        mov     r11, 0
+        mov     r12, 0
         // Jump to application
         bl      kmain
         // In case the application returns, loop forever
diff --git a/examples/mps3-an536/src/bin/smp_test.rs b/examples/mps3-an536/src/bin/smp_test.rs
index c7f8a76..6155787 100644
--- a/examples/mps3-an536/src/bin/smp_test.rs
+++ b/examples/mps3-an536/src/bin/smp_test.rs
@@ -209,6 +209,21 @@ core::arch::global_asm!(
         ldr     r0, [r0]
         // set up our stacks using that stack pointer
         bl      _stack_setup
+        // Zero all registers before calling kmain
+        mov     r0, 0
+        mov     r1, 0
+        mov     r2, 0
+        mov     r3, 0
+        mov     r4, 0
+        mov     r5, 0
+        mov     r6, 0
+        mov     r7, 0
+        mov     r8, 0
+        mov     r9, 0
+        mov     r10, 0
+        mov     r11, 0
+        mov     r12, 0
+        // call our kmain2 for core 1
         bl      kmain2
     .size _start, . - _start
     "#,