[U-Boot] [PATCH 2/2] ARM: davinci: SPL: fix BSS initialization

[Sekhar Nori]

On 21/05/19 9:01 PM, Adam Ford wrote:
> On Tue, May 21, 2019 at 10:09 AM Sekhar Nori <nsekhar at ti.com> wrote:
>>
>> U-Boot README recommends initializing SDRAM in board_init_f(). DA850
>> was doing it as part of board_init_r() (through call to spl_board_init()
>> which calls arch_cpu_init() which calls da850_ddr_setup())
>>
>> This worked fine till commit 15b8c7505819 ("davinci:
>> da850evm/omapl138-lcdk: Move BSS to SDRAM because SRAM is full") moved
>> BSS to SDRAM.
>>
>> Functions like mmc_initialize() called in board_init_r() assume BSS is
>> available. Since SDRAM was not initialized when arch/arm/lib/crt0.S tried
>> to initialize BSS to 0, BSS is not initialized correctly.
>>
>> Fix this by simply calling arch_cpu_init() from board_init_f(). Since the
>> README recommends calling preloader_console_init() from spl_board_init(),
>> we keep it as-it-is.
> 
> The README also states preloader_console_init() can get called from
> board_init_f().  Doing this enables for debugging of board_init_r

Okay, I can change it. spl_board_init() will be empty so I will turn off
 CONFIG_SPL_BOARD_INIT also.

I was put off by README saying "preloader_console_init() can be called
here in extremis" which I meant as saying it should be rare to do that.

Debugging board_init_r() should be pretty useful, so perhaps the wording
there should be more easy.

> 
>>
>> Tested using MMC/SD boot on OMAP-L138 LCDK board.
>>
>> Signed-off-by: Sekhar Nori <nsekhar at ti.com>
>> ---
>>  arch/arm/mach-davinci/spl.c | 6 +++++-
>>  1 file changed, 5 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/mach-davinci/spl.c b/arch/arm/mach-davinci/spl.c
>> index 103639e34757..117b5ee836f8 100644
>> --- a/arch/arm/mach-davinci/spl.c
>> +++ b/arch/arm/mach-davinci/spl.c
>> @@ -33,10 +33,14 @@ void putc(char c)
>>
>>  void spl_board_init(void)
>>  {
>> -       arch_cpu_init();
>>         preloader_console_init();
>>  }
>>
>> +void board_init_f(ulong dummy)
>> +{
>> +       arch_cpu_init();
> 
> What about a reference to board_early_init_f()?
> Looking at other boards, it appears that we should call that here.
> Both the LCDK and da850 evm have the function enabled to configure the
> DSP.

This is only needed at U-Boot stage, right? Looks like it will be called
because CONFIG_BOARD_EARLY_INIT_F is enabled.

Thanks,
Sekhar