Re: [PATCH v4 01/10] spacemit: k1: select boot device via config registers

[Yao Zi <me@ziyao.cc>]

On Tue, Jul 07, 2026 at 11:21:42PM +0800, Eric Chung wrote:
> Add logic to determine the current boot device by reading the
> SoC's configuration registers, rather than using a hardcoded
> default.
> 
> Signed-off-by: Eric Chung <eric.chung@riscstar.com>
> 
> ---
> v2:
> - Use FIELD_GET() to parse boot strap mode.
> - Remove comments on hacking. Since the sequence between eMMC
>   and SD device is exchanged in the upstream DTS. So it isn't
>   a hacking any more.
> ---
>  board/spacemit/k1/spl.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 68 insertions(+), 1 deletion(-)
> 
> diff --git a/board/spacemit/k1/spl.c b/board/spacemit/k1/spl.c
> index 0db362130e4..70579637b5e 100644
> --- a/board/spacemit/k1/spl.c
> +++ b/board/spacemit/k1/spl.c

...

> @@ -379,7 +402,51 @@ void board_init_f(ulong dummy)
>  
>  u32 spl_boot_device(void)
>  {
> -	return BOOT_DEVICE_SPI;
> +	void __iomem *boot_dev = (void __iomem *)BOOT_DEV_FLAG_REG;
> +	void __iomem *boot_strap = (void __iomem *)BOOT_PIN_SEL_REG;
> +	u32 mode, sel, ret = 0;
> +
> +	mode = readl(boot_dev);
> +	if (mode == BOOT_MODE_NONE || mode > BOOT_MODE_SD) {
> +		sel = FIELD_GET(BOOT_STRAP_MODE_MASK << BOOT_STRAP_MODE_OFFSET,
> +				readl(boot_strap));
> +		switch (sel) {
> +		case BOOT_STRAP_MODE_EMMC:
> +			mode = BOOT_MODE_EMMC;
> +			break;
> +		case BOOT_STRAP_MODE_NAND:
> +			mode = BOOT_MODE_NAND;
> +			break;
> +		case BOOT_STRAP_MODE_SPI:
> +			mode = BOOT_MODE_SPI;
> +			break;
> +		case BOOT_STRAP_MODE_SD:
> +		default:
> +			mode = BOOT_MODE_SD;
> +			break;
> +		}
> +	}
> +	switch (mode) {
> +	case BOOT_MODE_EMMC:
> +		ret = BOOT_DEVICE_MMC1;
> +		break;
> +	case BOOT_MODE_NAND:
> +		ret = BOOT_DEVICE_NAND;
> +		break;
> +	case BOOT_MODE_SPI:
> +		ret = BOOT_DEVICE_SPI;
> +		break;
> +	case BOOT_MODE_USB:
> +		ret = BOOT_DEVICE_USB;
> +		break;
> +	case BOOT_MODE_SD:
> +		ret = BOOT_DEVICE_MMC2;
> +		break;
> +	default:
> +		ret = BOOT_DEVICE_MMC1;
> +		break;
> +	}

Adding empty lines before and after this switch might make the code a
little cleaner. Though being a little strange to me, checkpatch.pl
doesn't complain about it, so I don't have a strong opinion for this.

Reviewed-by: Yao Zi <me@ziyao.cc>

Best regards,
Yao Zi