[U-Boot] [PATCH] rockchip: Fix SPL console output when ROCKCHIP_SPL_BACK_TO_BROM is enabled

[Simon Glass]

On 22 September 2016 at 20:28, Simon Glass <sjg at chromium.org> wrote:
> Acked-by: Simon Glass <sjg at chromium.org>
>
> On 13 August 2016 at 05:08, Ziyuan Xu <xzy.xu at rock-chips.com> wrote:
>> Acked-by: Ziyuan Xu <xzy.xu at rock-chips.com>
>>
>>
>> On 2016年08月11日 19:08, Sandy Patterson wrote:
>>>
>>>
>>> On Wed, Aug 10, 2016 at 11:01 PM, Ziyuan Xu <xzy.xu at rock-chips.com
>>> <mailto:xzy.xu at rock-chips.com>> wrote:
>>>
>>>
>>>
>>>     On 2016年08月10日 22:21, Sandy Patterson wrote:
>>>
>>>         Move back_to_bootrom() call later in SPL init so that the
>>>         console is
>>>         initialized and printouts happen.
>>>
>>>         Currently when ROCKCHIP_SPL_BACK_TO_BROM is enabled there is
>>>         no console
>>>         output from the SPL init stages.
>>>
>>>         I wasn't sure exactly where this should happen, so if we are
>>>         set to do
>>>         run spl_board_init, then go back to bootrom there after
>>>         preloader_console_init(). Otherwise fall back to old behavior
>>>         of doing
>>>         it in board_init_f.
>>>
>>>     In fact, ROCKCHIP_SPL_BACK_TO_BROM's aim is to reduce SPL's size,
>>>     and we can undef CONFIG_SPL_MMC_SUPPORT and other thing.
>>>     The SPL only in charge of DDR initialization, so that boot rom
>>>     could load u-boot to RAM.
>>>     If you really need something output, you can enable EARYLY_UART in
>>>     rk3288-board-spl.c:board_init_f().
>>>     But the above is my own understanding.
>>>
>>> EARLY_UART is a good tool, but this patch just fixes printouts. It's not
>>> enabling or disabling any code compilation. The console init and version
>>> information code is there. I just move the back_to_bootrom call later in the
>>> SPL if that later point exits. You can still disable CONFIG_SPL_BOARD_INIT
>>> and it will fall back to calling the bootrom earlier.
>>>
>>> We don't actually need that much space. We chose to use BOOT_TO_BROM
>>> instead of disabling the console in SPL.
>>>
>>> We disable CONFIG_SPL_MMC_SUPPORT in our production system within the
>>> rock2.h file if CONFIG_SPL_MMC_SUPPORT. I'll submit another patch for that.
>>> I think if boootrom is used then the mmc should be removed from spl. I'm not
>>> really sure how the config system is supposed to work in this case.


Applied to u-boot-rockchip, thanks!