移植ucos出現 Error: registers may not be the same -- `strexh r3,r2,[r3]' 處理

移植ucos在gcc的編譯環境，出現以下錯誤

Error: C:\Users\jack\AppData\Local\Temp\cch0iNvt.s:869: Error: registers may not be the same -- `strexh r3,r2,[r3]'

參考github代碼

https://gist.github.com/timbrom/1942280

修改core_cm3.c文件解決該問題

From 7341a316c38a61cc745ce04e618916677007883b Mon Sep 17 00:00:00 2001
From: Timothy Brom <[e-mail]>
Date: Wed, 29 Feb 2012 11:29:55 -0500
Subject: [PATCH] Fixed error about strexh and strexb using the same register

---
 example/libs_stm/inc/core_support/core_cm3.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/example/libs_stm/inc/core_support/core_cm3.c b/example/libs_stm/inc/core_support/core_cm3.c
index 56fddc5..0e8c3c4 100644
--- a/example/libs_stm/inc/core_support/core_cm3.c
+++ b/example/libs_stm/inc/core_support/core_cm3.c
@@ -733,7 +733,7 @@ uint32_t __STREXB(uint8_t value, uint8_t *addr)
 {
    uint32_t result=0;

-   __ASM volatile ("strexb %0, %2, [%1]" : "=r" (result) : "r" (addr), "r" (value) );
+   __ASM volatile ("strexb %0, %2, [%1]" : "=&r" (result) : "r" (addr), "r" (value) );
    return(result);
 }

@@ -750,7 +750,7 @@ uint32_t __STREXH(uint16_t value, uint16_t *addr)
 {
    uint32_t result=0;

-   __ASM volatile ("strexh %0, %2, [%1]" : "=r" (result) : "r" (addr), "r" (value) );
+   __ASM volatile ("strexh %0, %2, [%1]" : "=&r" (result) : "r" (addr), "r" (value) );
    return(result);
 }