[U-Boot] environment reliability after "env default -f -a"
Hi all,
It was noticed that after resetting the U-Boot environment ("env default -f -a") some variables are missing, and being added back after "reset". E.g. in my case it's next variables:
board_name=am57xx_evm_reva3 ethaddr=fc:0f:4b:7b:27:9c fastboot.board_rev=A.3A fastboot.cpu=DRA752 fastboot.secure=GP fastboot.userdata_size=2352351 fdtcontroladdr=fdf0d188 scsidevs=0 serial#=0c0090170f6e0122 stderr=serial@48020000 stdin=serial@48020000 stdout=serial@48020000 ver=U-Boot 2018.11-00028-g3ad6ba7780 (Nov 15 2018 - 21:17:57 +0200)
Most likely those variables are being set on board_late_init(), so we don't see them after "env default -f -a".
My question is: do we rely on environment to be the same after doing "env default -f -a", comparing to environment after reboot? If so, should I provide some sort of env callback to run corresponding routines on "env default" event (like [1])?
P.S. As I understand, we don't rely on this. But I didn't find this in documentation, so asking just to be completely sure.
Thanks!
Dear Sam,
In message CAKaJLVveZcdD-OCCRXCSJT0KVeWD1M9G+AqPxX9pSs4MRoLoaw@mail.gmail.com you wrote:
My question is: do we rely on environment to be the same after doing "env default -f -a", comparing to environment after reboot? If so, should I provide some sort of env callback to run corresponding routines on "env default" event (like [1])?
We should rather not rely on this.
I think many boards contain board-specific code to manipulate the environment, especially on first boot (and resetting the env usually makes the next boot a "first" one). You cannot scan all board specific code for such actions, or implement any generic handler for this.
[Well yes, maybe one could rewrite all such board-specific code into some common "first boot handler" that could be called from a central place, but who should do that?
Best regards,
Wolfgang Denk
Hi,
On Fri, Nov 16, 2018 at 3:20 PM Wolfgang Denk wd@denx.de wrote:
Dear Sam,
In message CAKaJLVveZcdD-OCCRXCSJT0KVeWD1M9G+AqPxX9pSs4MRoLoaw@mail.gmail.com you wrote:
My question is: do we rely on environment to be the same after doing "env default -f -a", comparing to environment after reboot? If so, should I provide some sort of env callback to run corresponding routines on "env default" event (like [1])?
We should rather not rely on this.
I think many boards contain board-specific code to manipulate the environment, especially on first boot (and resetting the env usually makes the next boot a "first" one). You cannot scan all board specific code for such actions, or implement any generic handler for this.
[Well yes, maybe one could rewrite all such board-specific code into some common "first boot handler" that could be called from a central place, but who should do that?
Sounds logical. Thank you for confirming this, Wolfgang!
Best regards,
Wolfgang Denk
-- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de As usual, this being a 1.3.x release, I haven't even compiled this kernel yet. So if it works, you should be doubly impressed. - Linus Torvalds in 199506181536.SAA10638@keos.cs.Helsinki.FI
participants (2)
-
Sam Protsenko -
Wolfgang Denk