+ switch_el x1, 3f, 2f, 1f
+ bl hang
+3: mrs x0, sctlr_el3
+ b 0f
+2: mrs x0, sctlr_el2
+ b 0f
+1: mrs x0, sctlr_el1
+0: tbz w0, #2, 5f /* skip flushing cache if disabled */
+ tbz w0, #12, 4f /* invalide i-cache is enabled */
+ ic iallu /* i-cache invalidate all */
+ isb sy
+4: ldp x0, x1, [sp, #16]
+ bl __asm_flush_dcache_range
+5: ldp x29, x30, [sp],#16