For early debug, the following configs needs to be enabled:

CONFIG_DEBUG_UART=y CONFIG_DEBUG_UART_OMAP=y CONFIG_DEBUG_UART_CLOCK=48000000 CONFIG_DEBUG_UART_SHIFT=2 CONFIG_DEBUG_UART_ANNOUNCE=y

For DRA7xx: CONFIG_DEBUG_UART_BASE=0x4806a000

For AM57xx: CONFIG_DEBUG_UART_BASE=0x48020000

Signed-off-by: Lokesh Vutla lokeshvutla@ti.com --- - Depends on DEBUG_UART_OMAP support patch[1] - Explicitly did not enable all the above configs by default as early debug is not need on every boot.

arch/arm/mach-omap2/hwinit-common.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/arch/arm/mach-omap2/hwinit-common.c b/arch/arm/mach-omap2/hwinit-common.c index f317293988..eb310be392 100644 --- a/arch/arm/mach-omap2/hwinit-common.c +++ b/arch/arm/mach-omap2/hwinit-common.c @@ -12,6 +12,7 @@ * SPDX-License-Identifier: GPL-2.0+ */ #include <common.h> +#include <debug_uart.h> #include <spl.h> #include <asm/arch/sys_proto.h> #include <linux/sizes.h> @@ -159,6 +160,9 @@ void early_system_init(void) setup_early_clocks(); do_board_detect(); vcores_init(); +#ifdef CONFIG_DEBUG_UART_OMAP + debug_uart_init(); +#endif prcm_init(); }