Hi Andy,
Am Montag, 3. Juli 2017, 16:02:59 CEST schrieb Andy Yan:
On 2017年06月30日 16:14, Dr. Philipp Tomsich wrote:
On 30 Jun 2017, at 09:47, Andy Yan andy.yan@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 is4384 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. 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.
For a start, maybe you could take a look at Simon's size reduction series from april. The TPL-specific stuff may not be that interesting, but the first patch adds a totally slimmed down memset, which may be better for real hard size constraints
[PATCH v2 0/5] Patches to reduce TPL code size: https://www.mail-archive.com/u-boot@lists.denx.de/msg243443.html
Heiko