FIELD_RETURN on i.MX8MNANOLPD4 EVK

[Ye Li]

I think there is no particular SW support needed for FIELD_RETURN on 8MN. 
From what you described, you have moved the part from closed to FIELD_RETURN. So are you 
able to boot into SPL without signature? 

Best regards,
Ye Li
> -----Original Message-----
> From: Peng Fan (OSS) <peng.fan at oss.nxp.com>
> Sent: Thursday, January 11, 2024 11:51 AM
> To: Thomas Schäfer <thomas.schaefer at kontron.com>; 'u-boot at lists.denx.de'
> <u-boot at lists.denx.de>; Ye Li <ye.li at nxp.com>
> Cc: Peng Fan <peng.fan at nxp.com>
> Subject: Re: FIELD_RETURN on i.MX8MNANOLPD4 EVK
> 
> +Ye
> 
> 在 1/9/2024 4:52 PM, Thomas Schaefer 写道:
> > Hi all,
> >
> > We are trying to enable FIELD RETURN on the NXP i.MX8MNano LPD4 EVK
> board.
> >
> > We enabled Secure Boot in u-boot in the first step. After checking proper
> execution of a signed bootloader image we closed the board blowing the
> SEC_CONFIG fuse.
> >
> > In the next step we created the board specific signature with UID of the CPU
> included to remove the FIELD RETURN lock. After that we were able to blow
> the FIELD_RETURN fuse with 'fuse prog 8 3 0x1' command. But now, the board
> cannot boot any more, it will hang after execution of the SPL bootloader part.
> >
> > We can observe this behavior with both signed and unsigned bootloader
> images.
> >
> > Is the FIELD_RETURN feature for the i.MX8MNano supported with u-boot
> v2024.01?
> >
> > Best regards,
> > Thomas
> >
> >
> > Thomas Schäfer
> > SW Design Engineer
> >
> > thomas.schaefer at kontron.com
> > www.kontron.com
> >
> >
> >
> >
> > Kontron Europe GmbH
> > Heinrich-Barth-Straße 1-1a | 66115 Saarbrücken | Germany