From 8087887afd9f661a797eb50e6ed24b03a5e12dba Mon Sep 17 00:00:00 2001
From: Dan Halbert <halbert@halwitz.org>
Date: Tue, 20 Dec 2022 22:18:43 -0500
Subject: [PATCH] Use returns_twice attribute to preserve regs in nlrthumb
 nlr_push()

---
 py/nlrthumb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/py/nlrthumb.c b/py/nlrthumb.c
index 30f9f2c196234..4b20d30c6ef8f 100644
--- a/py/nlrthumb.c
+++ b/py/nlrthumb.c
@@ -36,7 +36,7 @@
 // For reference, arm/thumb callee save regs are:
 //      r4-r11, r13=sp
 
-__attribute__((naked)) unsigned int nlr_push(nlr_buf_t *nlr) {
+__attribute__((naked, returns_twice)) unsigned int nlr_push(nlr_buf_t *nlr) {
 
     __asm volatile (
         "str    r4, [r0, #12]       \n" // store r4 into nlr_buf