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

[Heiko Schocher]

Hello Bo,

Am 19.01.2015 02:38, schrieb Bo Shen:
> Hi Heiko,
>
> On 01/16/2015 07:35 PM, Heiko Schocher wrote:
>> Hello Bo
>>
>> Am 16.01.2015 03:53, schrieb Bo Shen:
>>> 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 at 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
>>
>> Acked-by: Heiko Schocher <hs at denx.de>
>
> Thanks.
>
>> but it does not boot on the corvus board ... please add this fix to
>> your patch:
>>
>> diff --git a/include/configs/corvus.h b/include/configs/corvus.h
>> index efc8ce5..dc25d95 100644
>> --- a/include/configs/corvus.h
>> +++ b/include/configs/corvus.h
>> @@ -90,7 +90,7 @@
>>   #define CONFIG_SYS_SDRAM_SIZE          0x08000000
>>
>>   #ifdef CONFIG_SPL_BUILD
>> -#define CONFIG_SYS_INIT_SP_ADDR                0x310000
>> +#define CONFIG_SYS_INIT_SP_ADDR                (16 * 1024)
>>   #else
>>   #define CONFIG_SYS_INIT_SP_ADDR \
>>          (CONFIG_SYS_SDRAM_BASE + 4 * 1024 - GENERATED_GBL_DATA_SIZE)
>>
>>
>> Tested your patch also on the taurus board, there it boots fine!
>>
>> so, after you fixed the corvus board, you can add my:
>> Tested-by: Heiko Schocher <hs at denx.de>
>
> Thanks, I will add this fix into next version.

Thanks!

>> Thanks! And one question ...
>>
>> [...]
>>> 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 at 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
>>
>> Could we use here a new define (saying CONFIG_SYS_INIT_SP_LOWLEVEL)?
>>
>> Benefit would be, we can setup first the stack in sram, and after RAM
>> init, which is done with your patch very early, we can set the stack
>> with CONFIG_SYS_INIT_SP_ADDR into RAM!
>>
>> With using CONFIG_SYS_INIT_SP_ADDR here, the stack gets set twice
>> to CONFIG_SYS_INIT_SP_ADDR ... I just try to get SPL on an atsam9260
>> based board working with only 4k sram ... so it would be nice to
>> have stack also optionally in RAM ... but we have problems with the
>> debugger adapter on the board ... so I have to wait some more days to
>> try this part ...
>
>    This just for the at91sam9260 based boards, not for others. Or else, we also need to add this definition for other boards. Can you do the following check?
>
> #ifdef CONFIG_SYS_INIT_SP_LOWLEVEL
>      ldr    sp, =CONFIG_SYS_INIT_SP_LOWLEVEL
> #else
>      ldr    sp, =CONFIG_SYS_INIT_SP_ADDR
> #endif
>
>    If it is acceptable, can you add through your patches, as I my patch nowhere will use it.

Or we check if "CONFIG_SYS_INIT_SP_LOWLEVEL" is defined, if not
we set default to:
#define CONFIG_SYS_INIT_SP_LOWLEVEL	CONFIG_SYS_INIT_SP_ADDR

so, something like:

diff --git a/arch/arm/cpu/arm926ejs/at91/spl_lowlevel_init.S b/arch/arm/cpu/arm926ejs/at91/spl_lowlevel_init.S
index f1b2ec9..ed9adc7 100644
--- a/arch/arm/cpu/arm926ejs/at91/spl_lowlevel_init.S
+++ b/arch/arm/cpu/arm926ejs/at91/spl_lowlevel_init.S
@@ -15,11 +15,15 @@
  #include <config.h>
  #include <linux/linkage.h>

+#ifndef CONFIG_SYS_INIT_SP_ADDR_LOWLEVEL
+#define CONFIG_SYS_INIT_SP_ADDR_LOWLEVEL CONFIG_SYS_INIT_SP_ADDR
+#endif
+
  ENTRY(lowlevel_init)
         /*
          * Setup a temporary stack
          */
-       ldr     sp, =CONFIG_SYS_INIT_SP_ADDR
+       ldr     sp, =CONFIG_SYS_INIT_SP_ADDR_LOWLEVEL
         bic     sp, sp, #7 /* 8-byte alignment for ABI compliance */

         ldr     r9, =gdata

so we do not need to adapt existing boards, just add an entry
in README, that we have such a possibility now for at91 boards ...

bye,
Heiko
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