Re: [PATCH] rockchip: spl: Cache boot source id for later use

[Kever Yang <kever.yang@rock-chips.com>]

On 2024/3/16 01:34, Jonas Karlman wrote:
> Rockchip BROM write a boot source id at CFG_IRAM_BASE + 0x10, the id
> indicate from what storage media TPL/SPL was loaded from.
>
> SPL use this value to determine what device "same-as-spl" represent when
> determining from where FIT should be loaded. This works as long as the
> boot_devices array contain a matching id <-> node path entry.
>
> However, SPL typically load a small part of TF-A into SRAM and on RK3399
> this overwrites the CFG_IRAM_BASE + 0x10 addr used for boot source id.
>
> Here boot source id is 3 before FIT images is loaded, and 0 after:
>
>    U-Boot SPL 2024.04-rc4 (Mar 15 2024 - 17:26:19 +0000)
>    board_spl_was_booted_from: brom_bootdevice_id 3 maps to '/spi@ff1d0000/flash@0'
>    Trying to boot from SPI
>    ## Checking hash(es) for config config-1 ... OK
>    ## Checking hash(es) for Image atf-1 ... sha256+ OK
>    ## Checking hash(es) for Image u-boot ... sha256+ OK
>    ## Checking hash(es) for Image fdt-1 ... sha256+ OK
>    ## Checking hash(es) for Image atf-2 ... sha256+ OK
>    ## Checking hash(es) for Image atf-3 ... sha256+ OK
>    board_spl_was_booted_from: failed to resolve brom_bootdevice_id 0
>    spl_decode_boot_device: could not find udevice for /mmc@fe330000
>    spl_decode_boot_device: could not find udevice for /mmc@fe320000
>    spl_perform_fixups: could not map boot_device to ofpath: -19
>
> Use a static bootdevice_brom_id to cache the boot source id after an
> initial read from SRAM to fix this, this allow spl_perform_fixups() to
> resolve correct boot source path for "same-as-spl" after SPL have loaded
> TF-A related FIT images into memory.
>
> With this the spl-boot-device prop can correctly be resolved to the
> SPI flash node in the control FDT:
>
>    => fdt addr ${fdtcontroladdr}
>    Working FDT set to f1ee6710
>    => fdt list /chosen
>    chosen {
>        u-boot,spl-boot-device = "/spi@ff1d0000/flash@0";
>        stdout-path = "serial2:1500000n8";
>        u-boot,spl-boot-order = "same-as-spl", "/mmc@fe330000", "/mmc@fe320000";
>    };
>
> Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>

Thanks,
- Kever
> ---
>   arch/arm/mach-rockchip/spl.c | 10 +++++++++-
>   1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/mach-rockchip/spl.c b/arch/arm/mach-rockchip/spl.c
> index 1586a093fc37..27e996b504e7 100644
> --- a/arch/arm/mach-rockchip/spl.c
> +++ b/arch/arm/mach-rockchip/spl.c
> @@ -32,9 +32,17 @@ __weak const char * const boot_devices[BROM_LAST_BOOTSOURCE + 1] = {
>   
>   const char *board_spl_was_booted_from(void)
>   {
> -	u32  bootdevice_brom_id = readl(BROM_BOOTSOURCE_ID_ADDR);
> +	static u32 bootdevice_brom_id;
>   	const char *bootdevice_ofpath = NULL;
>   
> +	if (!bootdevice_brom_id)
> +		bootdevice_brom_id = readl(BROM_BOOTSOURCE_ID_ADDR);
> +	if (!bootdevice_brom_id) {
> +		debug("%s: unknown brom_bootdevice_id %x\n",
> +		      __func__, bootdevice_brom_id);
> +		return NULL;
> +	}
> +
>   	if (bootdevice_brom_id < ARRAY_SIZE(boot_devices))
>   		bootdevice_ofpath = boot_devices[bootdevice_brom_id];
>