[PATCH u-boot-mvebu 22/31] arm: mvebu: Always use BootROM for loading the rest of U-Boot's binary

[Baruch Siach]

Hi Marek, Pali,

On Thu, Jul 08 2021, Marek Behún wrote:
> From: Pali Rohár <pali at kernel.org>
>
> Now that proper load and execution addresses are set in v1 kwbimage, we
> can use BootROM to continue loading main U-Boot binary instead of
> U-Boot's SPL code.
>
> This also reduces the size of U-Boot's SPL image.
>
> The v1 kwbimage contains two separate executable parts: DDR training
> code (contains SPL) and bootloader (contains main U-Boot). BootROM first
> loads the first part, executes it and expects that the code returns back.
> Afterwards it loads the second part and executes it.
>
> The current SPL code (used for the first part) for non-UART/NAND boots
> never returns back to BootROM and loads main U-Boot from external storage
> itself, and it lets BootROM think that it is still executing the first
> part - DDR training code.
>
> With this change the SPL always returns execution back to BootROM and
> lets BootROM to load and execute U-Boot, like it was already done when
> booting from UART and NAND.
>
> Note that the config options CONFIG_SPL_SPI_FLASH_SUPPORT,
> CONFIG_SPL_SPI_LOAD and CONFIG_SPL_SPI_SUPPORT needs to be enabled as
> config option CONFIG_SYS_U_BOOT_OFFS (used by kwbimage) depends on it.

I think it's worth noting here that a subsequent commit will remove
both.

baruch

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