14:53 <amjad> Regarding AM335X EVM , mainline u-boot, I'm trying to apply an overlay dtbo to support PRUSS mode. The overlay shouldn't be apply for CPSW mode. But since for mainline we use sysboot command with extlinux/extlinux.conf located in boot medium, the overlay should be declared in extlinux.conf with "FDTOVERLAYS ../am335x-icev2-prueth.dtbo", but there

14:53 <amjad> isn't a clean way not load this overlay for CPSW mode. Therefore, I'm thinking of having two different extlinux.conf files, one with the overlay directive, the other without, and we choose the approriate file at run-time. Other solution is to have only one extlinux.conf file with the overlay directive, but we unset fdtoverlay_addr_r in u-boot env

14:53 <amjad> for CPSW mode so that sysboot skips loading the overlay, this will show an ugly unharmful error message but the boot continues

14:56 <amjad> What do you think of these two solutions ? is there any other mechanism you use to achieve the same end for mainline u-boot ?

16:07 <khilman> 07:53 <amjad> Regarding AM335X EVM , mainline u-boot, I'm trying to apply an overlay dtbo to support PRUSS mode. The overlay shouldn't be apply for CPSW mode. But since for mainline we use sysboot command with extlinux/extlinux.conf located in boot medium, the overlay should be declared in extlinux.conf with "FDTOVERLAYS ../am335x-icev2-prueth.dtbo", but there

16:07 <khilman> 07:56 <amjad> What do you think of these two solutions ? is there any other mechanism you use to achieve the same end for mainline u-boot ?

16:07 <khilman> 07:53 <amjad> isn't a clean way not load this overlay for CPSW mode. Therefore, I'm thinking of having two different extlinux.conf files, one with the overlay directive, the other without, and we choose the approriate file at run-time. Other solution is to have only one extlinux.conf file with the overlay directive, but we unset fdtoverlay_addr_r in u-boot env

16:07 <khilman> 07:53 <amjad> for CPSW mode so that sysboot skips loading the overlay, this will show an ugly unharmful error message but the boot continues

16:07 <khilman> Tartarus: repeating Amjad's question for you. ^^^

16:09 <Tartarus> Overlays and generic distro boot do indeed make for fun times.

16:11 <Tartarus> Now, extlinux.conf pops up a menu, so why not just 1 extlinux.conf with one entry for PRUSS and another for CPSW?

16:13 <amjad> Wouldn't we need to prompt the user to choose between the two ? In our use-case, we we would like to automatically choose the right entry based on an env variable (that is set based on the physical jumper configuration on the board)

16:13 <Tartarus> Yes, that would require user-intervention.

16:14 <Tartarus> So, hm

16:15 <Tartarus> I assume you're trying to not change bootcmd ?

16:18 <amjad> Well I think we can, our current bootcmd is: run findfdt; run init_console; run finduuid; run distro_bootcmd

16:18 <amjad> we mainly rely on the generic distro_bootcmd

16:19 <amjad> One thing that could make life easier is to add a new option to sysboot, to enable/disabled overlay application

16:20 <amjad> at runtime

16:22 <Tartarus> I'm not sure I like that

16:22 <Tartarus> Since the regular way to handle this would be to just select the right entry

16:22 <Tartarus> Well, lemme finish thinking out loud here :)

16:22 <Tartarus> You're trying to go for non-interactive selection of the right boot

16:23 <Tartarus> And there's not a way to change the default entry, it's always #1, yes?

16:23 <Tartarus> Some code change such that sysboot/etc checks a variable to know what the default entry should be, would be useful and I don't think violate the spec

16:23 <Tartarus> (but please check)

16:24 <Tartarus> Then you could just set the env var as you need it, based on the jumper, to entry #1/#2, whichever is PRUSS/CPSW in your setup

16:30 <amjad> This would be great actually, I'll double-check the sysboot code to make sure it can accomodate that change without breaking anything

16:31 <amjad> Thanks :)

16:36 <Tartarus> Welcome

16:37 <Tartarus> Tag me here or #u-boot if you have any other problems, there's other folks in #u-boot too of course :)