[U-Boot] [PATCH 0/5] fix the boot issue of Rockchip RK3036

[Dr. Philipp Tomsich]

For what it’s worth: GCC 7.1 (in an aarch64-unknown-elf configuration) is
now our default build-environment for our RK3399 and RK3368 boards and
works as expected.

> On 04 Jul 2017, at 15:32, Tom Rini <trini at konsulko.com> wrote:
> 
> On Mon, Jul 03, 2017 at 04:02:59PM +0800, Andy Yan wrote:
>> Hi Philipp:
>> 
>> 
>> On 2017年06月30日 16:14, Dr. Philipp Tomsich wrote:
>>> Andy,
>>> 
>>>> On 30 Jun 2017, at 09:47, Andy Yan <andy.yan at rock-chips.com> wrote:
>>>> 
>>>> 
>>>> As Kever mentioned in [0], the RK3036 based boards could't
>>>> bootup for a long time.
>>>> After a git bisect, I found the RK3036 SPL code size has
>>>> increased from patch [1] [2]. Before Tom's patch [1], the
>>>> SPL size is 3160 bytes, but it becomes 4080 bytes after [1]
>>>> applied. After a look at this patch, I realised I should
>>>> disable SPL_USE_ARCH_MEMCPY/MEMSET, and the code size indeed
>>>> come down after I disabled them. But I got a LD error after
>>>> apply patch[2]: "undefined reference to memset", RK3036 SPL
>>>> didn't use lib/string because of the sram space imitation.
>>>> The compile succeed after CONFIG_SPL_LIBGENERIC_SUPPORT enabled,
>>>> but the spl code size become 3248 bytes.
>>>> 
>>>> Additionally, Simon post patch [3] call printf to print a
>>>> message before back to bootrom from spl, which make the spl
>>>> code size increased to nearly 3.7 kb.
>>>> 
>>>> RK3036 SPL only has 4kb sram to use, the spl code will use
>>>> 3.4 ~ 3.5 kb, the last 0.5kb are used for SP and GD, so there
>>>> is no space for malloc.
>>> gcc-6-arm-linux-gnueabi
>>> What version of GCC are you using?
>>> If your problem can also be solved by moving to GCC 6.3 (or newer) and
>>> the code-size improvements there, I’d rather just require a more recent
>>> GCC version.
>> 
>>    I default use arm-linux-gnueabe-gcc v5.4.
>>    The current upstream kylin-rk3036_defconfig compiled by gcc-5.4
>> is 4384 bytes, the size comes down to 3936 bytes if I use
>> arm-linux-gnueabihf-gcc v6.3 from linaro. But this is still too
>> large for rk3036.
> 
> Please note that (and U-Boot should be complaining at you) that with
> v2018.01 we'll be moving to gcc-6.x or later for ARM.
> 
>>    Disable SPL_USE_ARCH_MEMCPY/MEMSET will make the spl size comes
>> down to 3042 bytes by gcc v6.3. But I still need some hack: enable
>> CONFIG_SPL_LIBGENERIC to get support for memset, masks Simon's print
>> in bootrom.c, or the code size will become very large. Event though
>> this hack make things work, we still lost a few hundreds bytes by
>> function board_init_f_alloc_reserve, because platforms with very
>> limit sram like rk3036 will return to bootrom after the dram
>> initialized, they never use the malloc space. This few hundreds
>> bytes is a large space for 4kb sarm,  it's better to letf them for
>> code or SP.
> 
> Since we're really size constrained here maybe it makes sense to move
> that print to a debug() ?
> 
> -- 
> Tom