Re: firmwareload fails for cortex-m7 on imx8mp

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

Hi Stefano,

On 15.11.24 16:01, Stefano Manni wrote:
> Il giorno ven 15 nov 2024 alle ore 15:49 Ahmad Fatoum
> 
> <a.fatoum@pengutronix.de> ha scritto:
>>
>> Hello Stefano,
>>
>> On 15.11.24 15:47, Stefano Manni wrote:
>>> Hello Ahmad,
>>>
>>> patch [1] works fine when M7 firmware is compiled to run from ITCM. Thank you!
>>
>> Thanks for testing.
>>
>>> But when I use exactly the same firmware but compiled to run from DDR
>>> (see [2]) I got:
>>>
>>> barebox@NXP i.MX8MPlus EVK board:/ firmwareload hello-ddr.elf
>>> remoteproc0: powering up remoteproc-cm7.of
>>> ERROR: remoteproc0: bad phdr da 0x80000000 mem 0x3de4
>>> ERROR: remoteproc0: Failed to load program segments: -22
>>>
>>> Note that I can run it both from linux and u-boot.

I am surprised it works for you in Linux. To get it working with barebox:

 1) run iomem and note where your malloc area begins. Set CONFIG_MALLOC_SIZE,
    so it starts after 0x90000000 

 2) Add the following to your DT:

&{/reserved-memory} {
	rproc_reserved: rproc@80000000 {
        	reg = <0 0x80000000 0 0x10000000>;
	};
};

&remoteproc_cm7 {
	memory-region = <&rproc_reserved>;
};

Do you not have an equivalent memory-region definition in your kernel DT?

 3) I found some issues that I just Cc'd you on the fixes for. They may not be
    necessary for the simple hello-ddr.elf example though.

Cheers,
Ahmad

>>>
>>> [1] https://lore.barebox.org/barebox/20241115135242.1251691-1-a.fatoum@pengutronix.de/
>>> [2] https://docs.zephyrproject.org/latest/boards/nxp/imx8mp_evk/doc/index.html#programming-and-debugging-m7
>>
>> Can you send me the ELF file, so I can look at the headers myself?
>>
>> Cheers,
>> Ahmad
>>
>>>
>>> Il giorno ven 15 nov 2024 alle ore 15:02 Ahmad Fatoum
>>> <a.fatoum@pengutronix.de> ha scritto:
>>>>
>>>> Hello Stefano,
>>>>
>>>> On 15.11.24 14:43, Stefano Manni wrote:
>>>>> Dear all,
>>>>>
>>>>> I cannot run an ELF image on the M7 core on the imx8mp soc.
>>>>> The ELF comes from zephyr and it runs as expected when I load it from linux,
>>>>> but in barebox I encounter this error:
>>>>>
>>>>> barebox@NXP i.MX8MPlus EVK board:/ tftp zephyr.elf
>>>>>         [################################################################]
>>>>> barebox@NXP i.MX8MPlus EVK board:/ firmwareload zephyr.elf
>>>>> remoteproc0: powering up remoteproc-cm7.of
>>>>> DABT (current EL) exception (ESR 0x96000061) at 0x00000000007e0004
>>>>
>>>> https://esr.arm64.dev/#0x96000061 decodes this as
>>>> "Abort caused by writing to memory" (Alignment fault) with valid FAR.
>>>>
>>>> FAR is the addresss listed here (0x00000000007e0004), which is indeed
>>>> not divisible by 8.
>>>>
>>>>> [<ffd826f4>] (__arch_memcpy+0x48/0x13c) from [<ffd82a00>] (memcpy+0xc/0x14)
>>>>
>>>> The optimized memcpy used here expects misalignment not to trap.
>>>>
>>>>> As you can see the exception happens when rproc_elf_load_segments() tries to
>>>>> memcpy a segment where the M7 expects it. The ELF has been compiled to run
>>>>> from ITCM memory (0x007E0000-0x007FFFFF).
>>>>>
>>>>> Do you have any idea? Maybe may I have to put a reserved-memory for ITCM?
>>>>
>>>> I think I may have broken this when I changed barebox to map everything outside
>>>> main memory as uncached.
>>>>
>>>> I did this, because we 1) don't want to risk the main CPU speculating into I/O
>>>> memory and 2) don't want to have to use memory barriers for synchronization.
>>>>
>>>> The flipside is that drivers that access I/O memory must do this via
>>>> readl/writel and friends or via memcpy_io/memset_io. This was already required
>>>> before, but some drivers that didn't do this were lucky enough to fly under
>>>> the radar. At least for remoteproc, this seems no longer the case.
>>>>
>>>> I just Cc'd you on a patch to fix this for remoteproc.
>>>> Please let me know with a Tested-by if this resolves your issue.
>>>>
>>>> Cheers,
>>>> Ahmad
>>>>
>>>>>
>>>>> Thank you.
>>>>>
>>>>> Best,
>>>>> Stefano
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> Pengutronix e.K.                           |                             |
>>>> Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
>>>> 31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
>>>> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
>>>
>>
>>
>> --
>> Pengutronix e.K.                           |                             |
>> Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
>> 31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
>> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
> 


-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |