iMXRT boards linker scrips

[Michal Lenc <mi...@seznam.cz>]

Hi everyone,



I was taking a look into Teensy 4.x ld scripts. They are mainly copied from 
imxrt1060-evk and they seem to be working fine, but I´ve run into some 
problems during recent work on imxrt_flexcan <https://github.com/michallenc/
incubator-nuttx/commits/can-rewrite/arch/arm/src/imxrt/imxrt_flexcan.c> so I
´ve also checked ld scripts. Pavel Píša sugested to change section 
alignement to 16 byte and to remove _eronly = ABSOLUTE(.); as it might couse
free space after alignement. We also added _eronly = LOADADDR(.data); after 
data sections. The whole change is in this commit <https://github.com/
michallenc/incubator-nuttx/commit/77a1c157907eff75e514125c5be09a2671342cae> 
(do not mind the changes in memory size). 




The question is we are not sure whether these changes are actually correct 
(my problems with CAN were coused by my mistakes during rewrite process and 
wer not related to ld scripts). It seems there is no change in running NuttX
on Teensy with old or new ld scripts. It would be great if someone with more
understading of binutuls could shed some light into this. If these changes 
are correct, then they should be also made into imxrt1060-evk, imxrt1050-evk
and imxrt1020-evk aswell.

PS: There has been some discussion about NuttX being involded in GsoC under 
Apache flag, was there any further development?



Best regards,
Michal Lenc