[U-Boot] [PATCH] ARM: atmel: at91sam9m10g45ek: enable SPL

[Bo Shen <voice.shen@atmel.com>]

Hi Andreas,

On 01/16/2015 05:10 PM, Andreas Bie?mann wrote:
> Hi Bo,
>
> just a short review, more will follow this weekend.
>
> On 01/16/2015 03:53 AM, Bo Shen wrote:
>> Supports boot up from NAND flash with software ECC eanbled.
>> And supports boot up from SD/MMC card with FAT file system.
>>
>> As the boot from SD/MMC card with FAT file system, the BSS
>> segment is too big to fit into SRAM, so, use the lds to put
>> it into SDRAM. So, we need to initialize the SDRAM as soon
>> as possible. Borrow the low level init code from
>> <arm/arm/cpu/armv7/lowlevel_init.S> for this purpose.
>>
>> As there is a little change, which need lowlevel init, so
>> also change taurus board based on at91sam9260, corvus board
>> based on at91sam9g45.
>> (CONFIG_SPL_STACK is replaced by CONFIG_SYS_INIT_SP_ADDR)
>>
>> Signed-off-by: Bo Shen <voice.shen@atmel.com>
>> ---
>>
>>   arch/arm/Kconfig                                |  1 +
>>   arch/arm/cpu/arm926ejs/at91/Makefile            |  4 ++
>>   arch/arm/cpu/arm926ejs/at91/spl_lowlevel_init.S | 37 ++++++++++++
>>   arch/arm/cpu/at91-common/spl_at91.c             |  7 +--
>>   arch/arm/cpu/at91-common/u-boot-spl-arm9.lds    | 48 +++++++++++++++
>>   board/atmel/at91sam9m10g45ek/at91sam9m10g45ek.c | 80 +++++++++++++++++++++++++
>>   configs/at91sam9m10g45ek_mmc_defconfig          |  5 +-
>>   configs/at91sam9m10g45ek_nandflash_defconfig    |  5 +-
>>   include/configs/at91sam9m10g45ek.h              | 65 ++++++++++++++++++++
>>   include/configs/corvus.h                        |  7 ++-
>>   include/configs/taurus.h                        |  7 ++-
>>   11 files changed, 256 insertions(+), 10 deletions(-)
>>   create mode 100644 arch/arm/cpu/arm926ejs/at91/spl_lowlevel_init.S
>>   create mode 100644 arch/arm/cpu/at91-common/u-boot-spl-arm9.lds
>>
>> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
>> index 5eb1d03..f4788c6 100644
>> --- a/arch/arm/Kconfig
>> +++ b/arch/arm/Kconfig
>> @@ -141,6 +141,7 @@ config TARGET_AT91SAM9263EK
>>   config TARGET_AT91SAM9M10G45EK
>>   	bool "Support at91sam9m10g45ek"
>>   	select CPU_ARM926EJS
>> +	select SUPPORT_SPL
>>
>>   config TARGET_AT91SAM9N12EK
>>   	bool "Support at91sam9n12ek"
>> diff --git a/arch/arm/cpu/arm926ejs/at91/Makefile b/arch/arm/cpu/arm926ejs/at91/Makefile
>> index 698a28d..238434b 100644
>> --- a/arch/arm/cpu/arm926ejs/at91/Makefile
>> +++ b/arch/arm/cpu/arm926ejs/at91/Makefile
>> @@ -25,5 +25,9 @@ obj-y	+= reset.o
>>   obj-y	+= timer.o
>>
>>   ifndef CONFIG_SKIP_LOWLEVEL_INIT
>> +ifdef CONFIG_SPL_BUILD
>> +obj-y	+= spl_lowlevel_init.o
>> +else
>>   obj-y	+= lowlevel_init.o
>>   endif
>> +endif
>
> I'm fine with having two variants of lowlevel_init for a time, but we
> should consolidate this and use C-style initialisation of SDRAM and
> stuff for the other armv5 at91 devices in future. AFAIK the
> a/a/c/arm926ejs/at91/lowlevel_init.S is mainly used for NOR Flash boots,
> so using the SPL code (but not necessarily the two binary mechanism) for
> the NOR Flash boots in future is appreciated.

OK, when all the arm9 at91 related board has SPL support, then I will do 
this.

>> diff --git a/arch/arm/cpu/arm926ejs/at91/spl_lowlevel_init.S b/arch/arm/cpu/arm926ejs/at91/spl_lowlevel_init.S
>> new file mode 100644
>> index 0000000..f1b2ec9
>> --- /dev/null
>> +++ b/arch/arm/cpu/arm926ejs/at91/spl_lowlevel_init.S
>> @@ -0,0 +1,37 @@
>> +/*
>> + * A lowlevel_init function that sets up the stack to call a C function to
>> + * perform further init.
>> + *
>> + * (C) Copyright 2010
>> + * Texas Instruments, <www.ti.com>
>> + *
>> + * Author :
>> + *	Aneesh V	<aneesh@ti.com>
>> + *
>> + * SPDX-License-Identifier:	GPL-2.0+
>> + */
>> +
>> +#include <asm-offsets.h>
>> +#include <config.h>
>> +#include <linux/linkage.h>
>> +
>> +ENTRY(lowlevel_init)
>> +	/*
>> +	 * Setup a temporary stack
>> +	 */
>> +	ldr	sp, =CONFIG_SYS_INIT_SP_ADDR
>> +	bic	sp, sp, #7 /* 8-byte alignment for ABI compliance */
>> +
>> +	ldr	r9, =gdata
>
> I remember some patches removing the SPL gdata stuff, is that true?

Thanks.

Yes, just search for it, the following patch do this.
http://patchwork.ozlabs.org/patch/423789/ (arm: Reduce the scope of 
lowlevel_init())

>> +
>> +	/*
>> +	 * Save the old lr(passed in ip) and the current lr to stack
>> +	 */
>> +	push	{ip, lr}
>> +
>> +	/*
>> +	 * go setup pll, mux, memory
>> +	 */
>> +	bl	s_init
>> +	pop	{ip, pc}
>> +ENDPROC(lowlevel_init)
>
> Rest of this patch will be reviewed later.

Thanks.

> Best regards
>
> Andreas Bie?mann
>

Best Regards,
Bo Shen