[U-Boot] [PATCH 2/2] arm: socfpga: Enable tiny printf and simple malloc in SPL

[Sylvain Lesne]

On 05/31/2016 05:42 PM, Marek Vasut wrote:
> On 05/31/2016 04:58 PM, Sylvain Lesne wrote:
>> Hi,
> 
> Hi,
> 
>> On 05/30/2016 05:22 PM, Marek Vasut wrote:
>>> Enable both features to reduce the SPL size by 6 kiB.
>>>
>>> Signed-off-by: Marek Vasut <marex at denx.de>
>>> Cc: Chin Liang See <clsee at altera.com>
>>> Cc: Dinh Nguyen <dinguyen at opensource.altera.com>
>>> Cc: Pavel Machek <pavel at denx.de>
>>> Cc: Stefan Roese <sr at denx.de>
>>
>> I tried to use the raw MMC boot (on the sockit, with current master
>> + your patches), so I changed the following:
>>
>> --- a/include/configs/socfpga_common.h
>> +++ b/include/configs/socfpga_common.h
>> @@ -349,9 +349,10 @@ unsigned int cm_get_qspi_controller_clk_hz(void);
>> #define CONFIG_SPL_FS_LOAD_PAYLOAD_NAME "u-boot-dtb.img"
>> #define CONFIG_SPL_LIBDISK_SUPPORT
>> #else
>> -#define CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 3
>> -#define CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR 0xa00 /* offset 2560
>> sect (1M+256k) */
>> -#define CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS 800 /* 400 KB */
>> +#define CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 3
>> +#define CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR 0x200 /* offset 512
>> sect (256k) */
>> +#define CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS 1000 /* 512 KB */
> 
> This should be 0x800 (was probably a typo in the original).
> Otherwise this should not break anything, yeah.
> 

I might be missing something obvious, but it actually seems that this
define isn't used outside of the include/configs/ folder...

>> +#define CONFIG_SPL_LIBDISK_SUPPORT
>> #endif
>> #endif
>>
>> AFAIK, there were two mistakes:
>> 1) FS_BOOT_PARTITION instead of RAW_MODE_U_BOOT
>> 2) CONFIG_SPL_LIBDISK_SUPPORT was missing
> 
> In fact, LIBDISK support was not used before you added the
> CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION into the board config.
> The libdisk functions are needed for determining the start of the
> partition. Looking through the SPL MMC, the code originally loaded the
> u-boot image from a fixed offset on the card (2560 sectors), which is
> indeed not optimal.
> 

I agree, but I thought that the CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
option was a bit confusing in this context! And I did not realise
the behaviour would be to load from a fixed offset.

As soon as the tiny printf "issue" is solved, I'll send this patch
(as I don't want to break the build).

> So yes, please send the above patch, it'd be a nice improvement.
> 
>> (I edited the offset to be able to use u-boot-with-spl.sfp directly)
>>
>> With these settings, I think we run into the size problem reported
>> previously in the ML.
>>
>> So, enabling tiny printf could help, but we now get:
>>
>> disk/built-in.o: In function `part_get_info_extended':
>> ...u-boot/disk/part_dos.c:236: undefined reference to `sprintf'
>>
>> So I think we can just put "info->name[0] = 0;" instead of
>> the snprintf() calls, when using tiny printf.
> 
> There is more of that stuff in disk/ , at least part_efi.c and
> part_iso.c suffer from the exact same problem. I am not sure if
> setting the name to '\0' wouldn't break anything, CCing Simon
> as he was recently digging in those areas.
> 
> Also, take a look at this patch:
> https://patchwork.ozlabs.org/patch/626760/

Ah yes, I naively only looked at the part_dos.c file. Actually
a tiny snprintf implementation by Simon was already merged!

http://git.denx.de/?p=u-boot.git;a=commit;h=5c411d88be8df5f6a8a1ea0c961f7c35ba82c064

If I implement a naive sprintf() using this as a basis, I can boot
from MMC without tweaking anything else, but it adds ~730 bytes
to tiny-printf.o.

Thanks!
Sylvain

> 
>> I can submit those changes as two patches if it makes sense.
> 
> Please do.
>