Hi Patrice,
On Fri, 17 Jan 2020 at 06:56, Patrice CHOTARD patrice.chotard@st.com wrote:
Hi All
Since the last sync of libfdt [1], boot time increase of 2.3 seconds on STM32MP1 dk2 board
On v2020.1 tag:
STM32MP> bootstage report Timer summary in microseconds (9 records): Mark Elapsed Stage 0 0 reset 571,804 571,804 board_init_f 3,535,935 2,964,131 board_init_r 3,954,721 418,786 id=64 4,006,006 51,285 id=65 4,006,708 702 main_loop 4,559,423 552,715 id=175
After reverting 'f0921f5098d8 (dt: Sync up to the latest libfdt)', boot time was restored:
STM32MP> bootstage report Timer summary in microseconds (9 records): Mark Elapsed Stage 0 0 reset 568,918 568,918 board_init_f 1,801,471 1,232,553 board_init_r 2,074,570 273,099 id=64 2,101,242 26,672 id=65 2,101,944 702 main_loop 3,229,354 1,127,410 id=175
After some investigation, the new implementation of fdt32_ld() is responsible of this time consuming.
Same issue has been already encountered on TF-A side [2]. TF-A community has decided to not update libfdt with v1.4.7
and stayed on the previous one v1.4.6 to avoid similar regression.
I think it would be worth having an option to use a simple read instead of the unaligned handling of fdt32_ld. We could have it as an assumption, e.g. fdt_chk_alignment().
Regards, Simon
Thanks
Patrice