Re: [PATCH 1/1] riscv: enable CONFIG_DEBUG_UART by default

[Leo Liang <ycliang@andestech.com>]

Hi Heinrich,

On Sat, Sep 23, 2023 at 01:35:26AM +0200, Heinrich Schuchardt wrote:
> Most boards don't enable the pre-console buffer. So we will not see any
> early messages. OpenSBI 1.3 provides us with the debug console extension
> that can fill this gap.
> 
> For S-Mode U-Boot enable CONFIG_DEBUG_UART by default.
> 
> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
> ---
>  arch/riscv/Kconfig | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 1c62c2345b..06fae7ebe8 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -141,6 +141,7 @@ config RISCV_MMODE
>  
>  config RISCV_SMODE
>  	bool "Supervisor"
> +	imply DEBUG_UART

This patch will cause the following compilation warnings.
Could you take a look at them ?

It seems that some configuration values will not be set
if we imply DEBUG_UART.

u-boot$ make qemu-riscv64_spl_defconfig
  HOSTCC  scripts/basic/fixdep
  HOSTCC  scripts/kconfig/conf.o
  YACC    scripts/kconfig/zconf.tab.c
  LEX     scripts/kconfig/zconf.lex.c
  HOSTCC  scripts/kconfig/zconf.tab.o
  HOSTLD  scripts/kconfig/conf
#
# configuration written to .config
#

u-boot$ make ARCH_FLAGS="-march=rv64imafdc" -j`nproc`
scripts/kconfig/conf  --syncconfig Kconfig
.config:78:warning: symbol value '' invalid for DEBUG_UART_BASE
.config:79:warning: symbol value '' invalid for DEBUG_UART_CLOCK
.config:1347:warning: symbol value '' invalid for SPL_DEBUG_UART_BASE
...

Best regards,
Leo

>  	help
>  	  Choose this option to build U-Boot for RISC-V S-Mode.
>  
> -- 
> 2.40.1
>