RE: [EXT] RE: [PATCHv2 0/7] hw/arm: Adding Cortex-M7 Asymmetric Multiprocessing boot support for i.MX8MP

NXP Confidential
> -----Original Message-----
> From: Bernhard Beschow <[email protected]>
> Sent: 23 August 2026 22:26
> To: Gaurav Sharma <[email protected]>; [email protected]
> Cc: [email protected]; [email protected]
> Subject: [EXT] RE: [PATCHv2 0/7] hw/arm: Adding Cortex-M7 Asymmetric
> Multiprocessing boot support for i.MX8MP
>
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>
> Am 23. August 2026 12:02:22 UTC schrieb Bernhard Beschow
> <[email protected]>:
> >
> >
> >Am 11. August 2026 04:47:40 UTC schrieb Gaurav Sharma
> <[email protected]>:
> >>ping
> >>
> >>> -----Original Message-----
> >>> From: Gaurav Sharma <[email protected]>
> >>> Sent: 24 July 2026 09:32
> >>> To: Gaurav Sharma <[email protected]>; qemu-
> [email protected]
> >>> Cc: [email protected]; [email protected]; Bernhard Beschow
> >>> <[email protected]>
> >>> Subject: RE: [PATCHv2 0/7] hw/arm: Adding Cortex-M7 Asymmetric
> >>> Multiprocessing boot support for i.MX8MP
> >>>
> >>> Ping
> >
> >Hi Gurav,
> >
> >I finally could test your series. I built Buildroot's
> freescale_imx8mpevk_defonfig (v2026.05) which has the required kernel
> options already enabled and passed imx8mp-evk-rpmsg.dtb to QEMU. QEMU
> starts successfully. However, when attempting to load an .elf image to
> remoteproc0/firmware, I get:
> >
> >    # echo zephyr.elf >
> >/sys/devices/platform/imx8mp-cm7/remoteproc/remoteproc0/firm
> >ware
> >    [  887.325597] imx-rproc imx8mp-cm7: can't change firmware while
> running
> >    sh: write error: Device or resource busy
> >
> >Checking the state results in:
> >
> >    # cat /sys/devices/platform/imx8mp-cm7/remoteproc/remoteproc0/state
> >    attached
> >
> >I didn't dig into the Linux kernel sources to investigate this further. Do you
> have an idea of what is missing?
>
> Okay, I missed the -mmio change as well as the reserved regions:
> https://docs.n/
> xp.com%2Fbundle%2FAN5317%2Fpage%2Ftopics%2Fimx_linux_rproc_suppo
> rt.html&data=05%7C02%7Cgaurav.sharma_7%40nxp.com%7Cba42497956e94
> 77b17c608df01376f9a%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%
> 7C639231009747150362%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGki
> OnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoy
> fQ%3D%3D%7C0%7C%7C%7C&sdata=VnPdMGYtloMgOrGjEMM8V0fAeyJ4PX
> 1mE0mDUQJiasA%3D&reserved=0 . Fixed.
>
> Then I set up MCUXpresso following this guide:
> https://mcuxpr/
> esso.nxp.com%2Fmcuxsdk%2Flatest%2Fhtml%2Fgsd%2Frepo_setup.html&dat
> a=05%7C02%7Cgaurav.sharma_7%40nxp.com%7Cba42497956e9477b17c608
> df01376f9a%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C6392310
> 09747181724%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUs
> IlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D
> %7C0%7C%7C%7C&sdata=9h%2BskLy4Ymmj5Hdm4bbxNWwBMVmTA%2Fj%2
> Bt2eAQvbKnrg%3D&reserved=0
>
> With an ARM eabi toolchain provided by my distrubution I created the .elf
> file:
>
>     west build -b evkmimx8mp examples/driver_examples/uart/polling/ --
> config ddr_release
>
> With the apporpriate .dtb I get in Buildroot guest:
>
>     # modprobe rpmsg_char
>     # echo uart_polling_cm7.elf > /sys/devices/platform/imx8mp-
> cm7/remoteproc/remoteproc0/firmware
>     # echo start > /sys/devices/platform/imx8mp-
> cm7/remoteproc/remoteproc0/state
>     [   52.182388] remoteproc remoteproc0: powering up imx-rproc
>     [   52.195672] remoteproc remoteproc0: Direct firmware load for
> uart_polling_cm7.elf failed with error -2
>     [   52.195895] remoteproc remoteproc0: Falling back to sysfs fallback for:
> uart_polling_cm7.elf
>     [  113.748324] remoteproc remoteproc0: request_firmware failed: -110
>     [  113.755836] remoteproc remoteproc0: Boot failed: -110
>     sh: write error: Connection timed out
>
> Any ideas?
>

Hey Bernhard,

Please copy the elf firmware to /lib/firmware directory before trying the above remoteproc loading. Linux kernel has a built-in firmware loader subsystem that automatically searches for firmware files in specific directories such as :-
/lib/firmware/

It is a one-time setup. The firmware loading should then work. I might have missed this copy step in the rst. I will add it.

> Best regards,
> Bernhard
>
> >
> >Note that I built Zephyr's imx8mp_evk for the M7 [1] which produces
> zephyr.elf. Does the series provide everything to use Zephyr or do we need to
> add ITCM memory? Adding a dedicated memory map including ITCM for the
> M7 core doesn't seem too complicated. Using Zephyr may allow for having a
> functional test in our CI, though of course binary images had to be provided.
> >
> >Best regards,
> >Bernhard
> >
> >[1]
> >https://docs/.
> >zephyrproject.org%2Flatest%2Fboards%2Fnxp%2Fimx8mp_evk%2Fdoc%2Fin
> dex.ht
> >ml%23programming-and-debugging-
> m7&data=05%7C02%7Cgaurav.sharma_7%40nxp.
> >com%7Cba42497956e9477b17c608df01376f9a%7C686ea1d3bc2b4c6fa92cd
> 99c5c3016
> >35%7C0%7C0%7C639231009747200340%7CUnknown%7CTWFpbGZsb3d8ey
> JFbXB0eU1hcGk
> >iOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIj
> oyfQ
> >%3D%3D%7C0%7C%7C%7C&sdata=cyY1qeaapUnyZB45dfZ5V4Os0S2gkQrrq
> MXR5XZ83fw%3
> >D&reserved=0
> >
> >
> >>>
> >>> > -----Original Message-----
> >>> > From: Gaurav Sharma <[email protected]>
> >>> > Sent: 06 July 2026 21:59
> >>> > To: [email protected]
> >>> > Cc: [email protected]; [email protected]; Gaurav Sharma
> >>> > <[email protected]>
> >>> > Subject: [PATCHv2 0/7] hw/arm: Adding Cortex-M7 Asymmetric
> >>> > Multiprocessing boot support for i.MX8MP
> >>> >
> >>> > Changes in v1:
> >>> >
> >>> > This series adds Asymmetric Multiprocessing (AMP) boot support for
> >>> > the
> >>> > Cortex-M7 core on the i.MX8MP SoC. The M7 firmware can be loaded
> >>> > and started from Linux running on the Cortex-A53 cores via the
> >>> > remoteproc framework.
> >>> >
> >>> > The series introduces the following peripheral models needed for AMP:
> >>> >   - GPC (General Power Controller)
> >>> >   - GPR (General Purpose Registers)
> >>> >   - SRC (System Reset Controller) authored by Bernhard Beschow
> >>> > <[email protected]>
> >>> >   - MU (Messaging Unit)
> >>> >   - Extends the CCM with M7 clock outputs and wires into the i.MX8MP
> SoC
> >>> >   - Enable Cortex-M7 boot in i.MX8MP EVK functional test
> >>> >
> >>> > Changes in v2:
> >>> >
> >>> > - Removed the usage of device_class_set_legacy_reset in imx8mp
> >>> > gpc,gpr,mu and
> >>> >   src.
> >>> > - Removed the usage of 'smp' , 'maxcpus' and 'enable-cm7' to make the
> >>> >   invocation simpler.
> >>> > - Cleaned up imx8mp_src by removing redundant/unused code.
> >>> > - Updated Maintainers and improved the imx8mp documentation
> >>> >
> >>> > Signed-off-by: Gaurav Sharma <[email protected]>
> >>> >
> >>> > Bernhard Beschow (1):
> >>> >   hw/misc: Add SRC (System Reset Controller) to i.MX8MP
> >>> >
> >>> > Gaurav Sharma (6):
> >>> >   hw/misc: Add i.MX8MP GPC (General Power Controller) IP
> >>> >   hw/misc: Add GPR (General Purpose Register) IP to iMX8MP
> >>> >   hw/misc: Add MU (Messaging Unit) IP to i.MX8MP device model
> >>> >   hw/misc: Extend i.MX8MP CCM with Cortex-M7 clock outputs
> >>> >   hw/arm: Enable Cortex-M7 AMP boot on i.MX8MP
> >>> >   tests/functional: Enable Cortex-M7 boot in i.MX8MP EVK
> >>> > functional test
> >>> >
> >>> >  MAINTAINERS                                 |  13 +-
> >>> >  docs/system/arm/imx8m.rst                   | 188 ++++++++++-
> >>> >  hw/arm/Kconfig                              |   4 +
> >>> >  hw/arm/fsl-imx8mp.c                         | 220 ++++++++++++-
> >>> >  hw/arm/imx8mp-evk.c                         |   3 +-
> >>> >  hw/misc/Kconfig                             |  12 +
> >>> >  hw/misc/imx8mp_ccm.c                        |   9 +
> >>> >  hw/misc/imx8mp_gpc.c                        | 146 +++++++++
> >>> >  hw/misc/imx8mp_gpr.c                        | 153 +++++++++
> >>> >  hw/misc/imx8mp_mu.c                         | 328 ++++++++++++++++++++
> >>> >  hw/misc/imx8mp_src.c                        | 275 ++++++++++++++++
> >>> >  hw/misc/meson.build                         |   4 +
> >>> >  hw/misc/trace-events                        |   5 +
> >>> >  include/hw/arm/fsl-imx8mp.h                 |  29 +-
> >>> >  include/hw/misc/imx8mp_ccm.h                |   3 +
> >>> >  include/hw/misc/imx8mp_gpc.h                |  34 ++
> >>> >  include/hw/misc/imx8mp_gpr.h                |  56 ++++
> >>> >  include/hw/misc/imx8mp_mu.h                 |  53 ++++
> >>> >  include/hw/misc/imx8mp_src.h                |  31 ++
> >>> >  tests/functional/aarch64/test_imx8mp_evk.py |   1 -
> >>> >  20 files changed, 1539 insertions(+), 28 deletions(-)  create
> >>> > mode
> >>> > 100644 hw/misc/imx8mp_gpc.c  create mode 100644
> >>> hw/misc/imx8mp_gpr.c
> >>> > create mode 100644 hw/misc/imx8mp_mu.c  create mode 100644
> >>> > hw/misc/imx8mp_src.c  create mode 100644
> >>> include/hw/misc/imx8mp_gpc.h
> >>> > create mode 100644 include/hw/misc/imx8mp_gpr.h  create mode
> >>> > 100644 include/hw/misc/imx8mp_mu.h  create mode 100644
> >>> > include/hw/misc/imx8mp_src.h
> >>> >
> >>> > --
> >>> > 2.34.1
> >>