Hi all, I am testing the latest kernel(4.8+) on my S5PV210 ARM boards. I found I have to add the kputc debug in __armv7_mmu_cache_on in boot/compressed/head.S: mov r11, r3 kputc #'x' mov r3, r11 Without the above kputc, the kernel boot hang, there is no any output on UART Any suggestions? Thanks, Yong