FIELD_RETURN on i.MX8MNANOLPD4 EVK

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@kontron.com www.kontron.com
Kontron Europe GmbH Heinrich-Barth-Straße 1-1a | 66115 Saarbrücken | Germany

+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@kontron.com www.kontron.com
Kontron Europe GmbH Heinrich-Barth-Straße 1-1a | 66115 Saarbrücken | Germany

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@oss.nxp.com Sent: Thursday, January 11, 2024 11:51 AM To: Thomas Schäfer thomas.schaefer@kontron.com; 'u-boot@lists.denx.de' u-boot@lists.denx.de; Ye Li ye.li@nxp.com Cc: Peng Fan peng.fan@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@kontron.com www.kontron.com
Kontron Europe GmbH Heinrich-Barth-Straße 1-1a | 66115 Saarbrücken | Germany

Hi Ye,
Yes, I can boot SPL without signature. I also added some debug messages to my build and I can see that SPL can load u-boot proper via USB until 'Jumping to U-Boot' message in board_init_r function (common/spl/spl.c)
Actually this looks like the SError problem caused by errata ERR050350 which has been worked around in patch 2f3c92060dcd. But that patch is currently active in u-boot and so I don't understand what the problem is here in this case.
Best regards, Thomas
-----Ursprüngliche Nachricht----- Von: Ye Li ye.li@nxp.com Gesendet: Donnerstag, 11. Januar 2024 05:09 An: Peng Fan (OSS) peng.fan@oss.nxp.com; Thomas Schaefer thomas.schaefer@kontron.com; 'u-boot@lists.denx.de' u-boot@lists.denx.de Cc: Peng Fan peng.fan@nxp.com Betreff: RE: FIELD_RETURN on i.MX8MNANOLPD4 EVK
[You don't often get email from ye.li@nxp.com. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
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@oss.nxp.com Sent: Thursday, January 11, 2024 11:51 AM To: Thomas Schäfer thomas.schaefer@kontron.com; 'u-boot@lists.denx.de' u-boot@lists.denx.de; Ye Li ye.li@nxp.com Cc: Peng Fan peng.fan@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@kontron.com https://eur04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww .kontron.com%2F&data=05%7C02%7Cthomas.schaefer%40kontron.com%7C7eb38 f57a0304f030f2f08dc125b1c74%7C8c9d3c973fd941c8a2b1646f3942daf1%7C0%7 C0%7C638405429733492095%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAi LCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata =nOuWb2NSpPBRl5FaV8xa5MiQZ%2FzE7z8F%2FC2Rfv%2F7yzo%3D&reserved=0
Kontron Europe GmbH Heinrich-Barth-Straße 1-1a | 66115 Saarbrücken | Germany

Hi Thomas,
It is due to ARMV8_SPL_EXCEPTION_VECTORS not enabled by default in upstream. I will send a patch
Best regards, Ye Li
-----Original Message----- From: Thomas Schaefer Thomas.Schaefer@kontron.com Sent: Thursday, January 11, 2024 9:40 PM To: Ye Li ye.li@nxp.com; Peng Fan (OSS) peng.fan@oss.nxp.com; 'u-boot@lists.denx.de' u-boot@lists.denx.de Cc: Peng Fan peng.fan@nxp.com Subject: [EXT] AW: FIELD_RETURN on i.MX8MNANOLPD4 EVK
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Hi Ye,
Yes, I can boot SPL without signature. I also added some debug messages to my build and I can see that SPL can load u-boot proper via USB until 'Jumping to U-Boot' message in board_init_r function (common/spl/spl.c)
Actually this looks like the SError problem caused by errata ERR050350 which has been worked around in patch 2f3c92060dcd. But that patch is currently active in u-boot and so I don't understand what the problem is here in this case.
Best regards, Thomas
-----Ursprüngliche Nachricht----- Von: Ye Li ye.li@nxp.com Gesendet: Donnerstag, 11. Januar 2024 05:09 An: Peng Fan (OSS) peng.fan@oss.nxp.com; Thomas Schaefer thomas.schaefer@kontron.com; 'u-boot@lists.denx.de' u-boot@lists.denx.de Cc: Peng Fan peng.fan@nxp.com Betreff: RE: FIELD_RETURN on i.MX8MNANOLPD4 EVK
[You don't often get email from ye.li@nxp.com. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
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@oss.nxp.com Sent: Thursday, January 11, 2024 11:51 AM To: Thomas Schäfer thomas.schaefer@kontron.com; 'u-boot@lists.denx.de' u-boot@lists.denx.de; Ye Li ye.li@nxp.com Cc: Peng Fan peng.fan@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@kontron.com https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww %2F&data=05%7C02%7Cye.li%40nxp.com%7C060b2d6efc44474f6b6308dc1
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Kontron Europe GmbH Heinrich-Barth-Straße 1-1a | 66115 Saarbrücken | Germany
participants (3)
-
Peng Fan
-
Thomas Schaefer
-
Ye Li