ERROR - "Back to ROM, SDP" on i.MX 8M Mini

[danie007]

We're trying to flash the bootloader on CompuLab IOT-GATE-iMX8 EVK that is based on NXP i.MX 8MM application processor, we get the following error.

U-Boot SPL 2020.04-iot-gate-imx8-2.3-5.4.24-2.1.0+g4979a99482 (May 28 2021 - 06:32:44 +0000)
power_bd71837_init
DDRINFO(D): Nanya 2048G
DDRINFO: start DRAM init
DDRINFO:ddrphy calibration done
DDRINFO: ddrmix config done
DDRINFO(M): mr5-8 [ 0x5000010 ]
DDRINFO(E): mr5-8 [ 0x5000010 ]
Back to ROM, SDP

We referenced this issue, which talks about "Back to ROM, SDP" error and verified that we're using the latest and supported U-Boot version (v2020.04).

It is to be noted that, the above error message gets printed as soon as we changed to SDP. And when we try to run the UUU flashing script, it does not respond at all.

NOTE: We checked that the SDP is working by running the uuu -lsusb command and also checked that fastboot is enabled and working on the U-Boot.

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CC @tkmozhi

[danie007]

@nxpfrankli can you comment on this?

[nxpfrankli]

Back to ROM, SDP is old method. We have give up this way.

Please check config and nxp release uboot. nxp 2020 uboot should already switch SPL SDP.

[danie007]

Our U-Boot version is 2020.04 yet we're seeing this error! What does that signify?

Please check config and nxp release uboot.

What should I be checking on these? Could you be more specific.

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CC @tkmozhi

[nxpfrankli]

It is boards file. refer: board/freescale/imx8mm_evk/spl.c

int spl_board_boot_device(enum boot_device boot_dev_spl) { switch (boot_dev_spl) { case SD2_BOOT: case MMC2_BOOT: return BOOT_DEVICE_MMC1; case SD3_BOOT: case MMC3_BOOT: return BOOT_DEVICE_MMC2; case QSPI_BOOT: return BOOT_DEVICE_NOR; case NAND_BOOT: return BOOT_DEVICE_NAND; case USB_BOOT: return BOOT_DEVICE_BOARD; default: return BOOT_DEVICE_NONE; } }

Need return BOOT_DEVICE_BOARD.

[danie007]

@nxpfrankli I've verified the above functions on the NXP i.MX 8MM EVK and everything works as expected. However in CompuLab BSP, it's seem like that they've scraped the SDP related parts.

If the CompuLab BSP is void of these options, how should I add these? Are there any references?

Thanks in advance.

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CC @tkmozhi

[nxpfrankli]

what's your means? board/freescale/imx8mm_evk/spl.c is refer code.

[danie007]

@nxpfrankli Thanks for your support 😇 The issue is resolved with this patch note from one of the collaborators (@vraevsky) of compulab-yokneam/meta-bsp-imx8mm repo.

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CC @tkmozhi