arvm7m: add cleanup before linux booting
Data cache memory needs to be disabled before handing over control to
linux kernel. This patch populates the cleanup_before_linux stub.
Signed-off-by: Vikas Manocha <vikas.manocha@st.com>
diff --git a/arch/arm/cpu/armv7m/cpu.c b/arch/arm/cpu/armv7m/cpu.c
index 58cde93..a424bab 100644
--- a/arch/arm/cpu/armv7m/cpu.c
+++ b/arch/arm/cpu/armv7m/cpu.c
@@ -18,6 +18,25 @@
*/
int cleanup_before_linux(void)
{
+ /*
+ * this function is called just before we call linux
+ * it prepares the processor for linux
+ *
+ * disable interrupt and turn off caches etc ...
+ */
+ disable_interrupts();
+ /*
+ * turn off D-cache
+ * dcache_disable() in turn flushes the d-cache
+ * MPU is still enabled & can't be disabled as the u-boot
+ * code might be running in sdram which by default is not
+ * executable area.
+ */
+ dcache_disable();
+ /* invalidate to make sure no cache line gets dirty between
+ * dcache flushing and disabling dcache */
+ invalidate_dcache_all();
+
return 0;
}