Add volatile qualifier (FreeRTOS#1283)

aggarg · web-flow · commit 28a20d5a6971 · 2024-10-17T11:08:16.000+05:30
Add volatile qualifier

This is needed to ensure that the memory mapped address it always read.

Signed-off-by: Gaurav Aggarwal &lt;aggarg@amazon.com&gt;
diff --git a/.gitignore b/.gitignore
@@ -11,6 +11,7 @@
 [Oo]bj/
 [Ll]og/
 [Ll]ogs/
+[Bb]uild/
 
 # CodeWarrior temporary files
 *.tdt
diff --git a/FreeRTOS/Demo/RISC-V-Qemu-virt_GCC/ns16550.c b/FreeRTOS/Demo/RISC-V-Qemu-virt_GCC/ns16550.c
@@ -20,7 +20,7 @@
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  *
  * https://www.FreeRTOS.org
- * https://www.github.com/FreeRTOS
+ * https://github.com/FreeRTOS
  *
  */
 
@@ -54,12 +54,12 @@
 
 static uint8_t readb( uintptr_t addr )
 {
-	return *( (uint8_t *) addr );
+	return *( (volatile uint8_t *) addr );
 }
 
 static void writeb( uint8_t b, uintptr_t addr )
 {
-	*( (uint8_t *) addr ) = b;
+	*( (volatile uint8_t *) addr ) = b;
 }
 
 void vOutNS16550( struct device *dev, unsigned char c )

Original file line number	Diff line number	Diff line change
`@@ -20,7 +20,7 @@`
`20`	`20`	`* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.`
`21`	`21`	`*`
`22`	`22`	`* https://www.FreeRTOS.org`
`23`		`- * https://www.github.com/FreeRTOS`
	`23`	`+ * https://github.com/FreeRTOS`
`24`	`24`	`*`
`25`	`25`	`*/`
`26`	`26`
`@@ -54,12 +54,12 @@`
`54`	`54`
`55`	`55`	`static uint8_t readb( uintptr_t addr )`
`56`	`56`	`{`
`57`		`- return ( (uint8_t ) addr );`
	`57`	`+ return ( (volatile uint8_t ) addr );`
`58`	`58`	`}`
`59`	`59`
`60`	`60`	`static void writeb( uint8_t b, uintptr_t addr )`
`61`	`61`	`{`
`62`		`- ( (uint8_t ) addr ) = b;`
	`62`	`+ ( (volatile uint8_t ) addr ) = b;`
`63`	`63`	`}`
`64`	`64`
`65`	`65`	`void vOutNS16550( struct device *dev, unsigned char c )`