Linux4sam_5.7 on G25 UBI rootfs problems

[psutter]

We have been using a Linux 3.16 on buildroot 2014 for quite some time in a configuration where we boot the kernel and dtb directly from nand flash with the Atmel first stage boot loader and then mount a ubi root file system that is also in nand flash.

We recently moved this same configuration forward to use Linux4sam_5.7 (linux 4.9) on buildroot 2017. With this new build, the Atmel first stage boot loader successfully loads the dtb and the kernel and the kernel successfully runs and configures properly until it gets to mounting the ubi root file system. At this point there is a constant flood of PMECC errors (-74).

Has anyone successfully used this latest version of Linux4sam_5.7 in a similar direct, first stage boot configuration on the G25?

Thanks,
Phil

[blue_z]

We have been using a Linux 3.16 on buildroot 2014 for quite some time in a configuration where we boot the kernel and dtb directly from nand flash with the Atmel first stage boot loader and then mount a ubi root file system that is also in nand flash.

The Atmel first-stage bootloader is the ROM boot program (aka RomBOOT) embedded in the SoC. This is documented in the datasheet.
AT91Bootstrap is a second-stage bootloader, since it is loaded by RomBOOT.
UBI is a volume manager, and not a filesystem.
UBIFS is presumably the filesystem that you're using?

At this point there is a constant flood of PMECC errors (-74).

That is an inadequate description of the problem.
74 maps to errno EBADMSG, which is generated by several routines in several UBI-related files.

Has anyone successfully used this latest version of Linux4sam_5.7 in a similar direct, first stage boot configuration on the G25?

That's your sole question?
Except for some "bit flip" messages IIRC the handful of similar PMECC and UBI issues posted at this site all had confirmed root causes that traced back to the user at the keyboard.

Since you seem to implicate this "first [sic] stage boot loader", why have you neglected to mention it by its name and indicate which version(s) that you're using?

Regards