Hello,
Hardware:
- i.MX8MQ (REV A0), custom board based on EVK design
- QSPI NOR: Micron MT25QL256A (32MB, 3.3V, Quad connected)
- BSP: Yocto Scarthgap, NXP BSP, U-Boot 2024.04 (u-boot-imx)
Goal: Boot the bootloader (SPL + ATF + U-Boot) from FlexSPI NOR flash.
Kernel and rootfs remain on eMMC.
What works:
- U-Boot (loaded to RAM via uuu SDP/SDPV) runs fine
- "sf probe" detects the flash correctly: mt25ql256a, 32 MiB
- U-Boot can read and write the flash reliably (verified with
read-back tests after "sf protect unlock")
- Image is built with IMXBOOT_TARGETS = "flash_evk_flexspi"
Flash layout (verified by reading back from the chip):
0x000000: FCFB header - "qspihdr check" reports
"Found boot config header in Q(F)SPI"
tag = 42464346, version = 56010000
0x001000: IVT - d1 00 20 41, entry = 0x007E1000,
boot_data = 0x007E0FE0, self = 0x007E0FC0
0x060000: U-Boot proper FIT (d00dfeed), matches
CONFIG_SYS_SPI_U_BOOT_OFFS=0x60000
Problem:
With boot switches set to QSPI/FlexSPI boot and the USB cable
physically disconnected, the board does not boot. Nothing is
printed on the serial console (SPL banner never appears), and
the ROM falls back to serial download mode:
uuu -lsusb
2:1 MX8MQ SDP: 0x1FC9 0x012B NXP FLASH
BT_FUSE_SEL is not blown; boot configuration is done via GPIO
boot pins.
What I have already tried:
- Both header formats: scripts/qspi_header (c0ffee01 tag) and
scripts/fspi_header (FCFB tag). Fixed soc.mak so that
flash_evk_flexspi uses fspi_header with offset 0.
- Varying FCFB parameters: sflashA1Size, serialClkFreq (50MHz -> 20MHz),
dataSetupTime/dataHoldTime, sflashPadType
- "uuu -b qspi" (the official built-in script)
- "qspihdr update safe" and "qspihdr init
- Erasing the flash completely vs. writing the full image:
boot behaviour is essentially identical (SDP appears after
~1.6s vs ~1.8s), which suggests the ROM may not be reading
the flash at all.
Questions:
1. Does the i.MX8MQ Boot ROM support booting from serial NOR
flash over FlexSPI at all? The Reference Manual section I have
lists NAND flash and SD/MMC as boot devices, but I could not
find FlexSPI/QSPI NOR listed. i.MX8MM/8MN documentation seems
to describe it, but I am unsure about 8MQ.
2. If it is supported, what is the exact expected flash layout?
Should the IVT be at offset 0x400 or 0x1000 when an FCFB is
present at 0x0?
3. What is the correct BOOT_MODE / BOOT_CFG combination to select
FlexSPI NOR boot on i.MX8MQ?
4. Are there any known errata for REV A0 silicon regarding
FlexSPI boot?
Thank you.
Hello, I'm working on a similar task.
Some sections on the same document mentions some boot options using SPI.
Would you like to elaborate further please?
Is there absolutely no way to boot the i.MX8MQ from QSPI NOR Flash while keeping the Linux kernel and root filesystem on eMMC? Our hardware design has already been built around this architecture, so it is very important for us.
Hi,
Please refer primarily to the information in the RM; the i.MX8MQ does not support QSPI boot.
Best Regards,
Zhiming
Dear NXP Technical Support Team,
We would like to raise a serious concern regarding the documentation of QSPI boot support for the i.MX8MQ.
Engineers rely on the Reference Manual as the primary and authoritative source when making hardware design decisions. When a boot source is listed or implied as supported in the Reference Manual, it is entirely reasonable for a development team to design the board around that information.
This is not a minor typographical mistake. Boot-source selection directly affects schematic design, PCB layout, component selection, manufacturing, firmware architecture, recovery strategy, and product validation. An incorrect statement regarding QSPI boot capability can therefore result in significant engineering time loss, additional prototype revisions, delayed schedules, and substantial financial cost.
It is especially concerning that similar questions and feedback appear to have been raised in the NXP community since approximately 2017–2018, while the documentation has apparently remained unclear or incorrect for many years. If NXP has known that the i.MX8MQ Boot ROM does not support direct boot from QSPI, this limitation should have been clearly stated in the Reference Manual, device errata, application notes, and product documentation.
Leaving such a critical ambiguity unresolved for years is unacceptable for a component used in professional and commercial hardware designs. Customers must be able to trust the information provided in the official Reference Manual.
We therefore request a clear and formal response to the following points:
- Does the i.MX8MQ Boot ROM support direct boot from QSPI NOR after power-on reset?
- If it does not, why was QSPI presented or implied as a supported boot option in the Reference Manual?
- Has NXP officially classified this as a documentation error?
- In which document revision will this information be corrected?
- Will NXP publish an erratum or product notice to warn customers who may have designed hardware based on the existing documentation?
- Is there any officially supported workaround that allows the Boot ROM to load the initial boot image directly from QSPI without requiring SD or eMMC?
We strongly believe this issue requires more than an informal forum response. A formal documentation correction and an explicit technical notice are necessary to prevent other engineering teams from experiencing the same time and financial losses.
Please escalate this matter to the i.MX8MQ product engineering and documentation teams and provide an authoritative written clarification.
Hello @Zhiming_Liu, @ayse-yilmaz
I've found the following topic related to this very problem: https://community.nxp.com/t5/i-MX-Processors/Does-i-MX8M-support-boot-from-QSPI/m-p/904429#M136467
But as a solution, tech support mentioned "for development purposes, the eFUSEs used to determine the boot device may be overridden using the GPIO pin inputs" but boot ROM does not support it anyway. I'm a bit confused here. Why even though the HW supports it, boot ROM doesn't?
I guess it's impossible to boot from QuadSPI despite of the HW and the documents, due to ROM. Is my understanding right? Please kindly elaborate.
Thx,
Onur
Regards
Issues with the documentation in Chapter 6
For the supported boot device, should refer the 6.1 System boot.
About 1.6 Primary Boot Options, it looks like a document residue.
Best Regards,
Zhiming