IMX8M and Optee support

Hans Christian Lønstad hcl at datarespons.no
Wed Oct 18 23:23:26 PDT 2023


Note that Optee is not build using position independence, so one will need to set CFG_TZDRAM_START to
the Barebox (endmem-OPTEE_SIZE) location.

This inconvenience makes the use of passed parameters less relevant given a compile time
resolution is required.

Hans

> 18. okt. 2023 kl. 16:36 skrev Ahmad Fatoum <a.fatoum at pengutronix.de>:
> 
> Hello Hans,
> 
> On 18.10.23 16:06, Hans Christian Lønstad wrote:
>> The ATF for imx8 is quite convoluted requiring fixed memory locations for images and device trees. The ATF itself supports transferring parameters
>> Using 4 unsigned long arguments. These are unfortunately zeroed out by a misconfiguration for IMX8:
>> 
>> RESET_TO_BL31 := 1
>> and not at the same time setting
>> RESET_TO_BL31_WITH_PARAMS := 1
>> 
>> As demoed below this can be made to work.
>> ———><——
>> 
>> Uart initialized
>> Run level 3
>> Init power
>> Init DDR
>> Handover to ATF
>> imx8mp_load_and_start_image_via_tfa: Expect OPTEE at 0xbe000000
>> CH e2a7175151fe3e842116990e62c864334e1bb030ca146b749d8e6b0c02481357
>> IH e2a7175151fe3e842116990e62c864334e1bb030ca146b749d8e6b0c02481357
>>                                                                   CAAM early init successful
>> imx8m_atf_start_bl31: Callout BL31 with 1, 2, 3, 4
>> NOTICE:  Do not release JR0 to NS as it can be used by HAB
>> INFO:    bl31_early_platform_setup2: args are 0x00000001, 0x00000002, 0x00000003, 0x00000004
>> NOTICE:  BL31: v2.8(debug):lf-6.1.36-2.1.0-0-g1a3beeab6-dirty
>> NOTICE:  BL31: Built : 15:49:38, Oct 18 2023
>> 
>> ——><——
>> 
>> The "best" approach is likely to patch ATFs imx8mX_bl31_setup.c replacing preprocessor values with values
>> handed over from Barebox. Adding these parameters will be compatible with unpatched ATFs anyway.
> 
> There's void bl31_entry(uintptr_t bl31_entry, uintptr_t bl32_entry,
>         uintptr_t bl33_entry, uintptr_t fdt_addr)
> 
> which is used for RK3568/RK3588 platforms. AFAIU, future SoCs will likely
> use a linked list of hand over blocks to transfer this same information.
> 
> Any of these two approaches would be better than what we have now on i.MX.
> 
> I am still not sure how this relates to OP-TEE hanging. Can you configure
> your OP-TEE to not expect a FDT?
> 
> Cheers,
> Ahmad
> 
>> 
>> Hans
>> 
>> 
>>> 18. okt. 2023 kl. 15:04 skrev Ahmad Fatoum <a.fatoum at pengutronix.de>:
>>> 
>>> Hello,
>>> 
>>> On 18.10.23 14:31, Hans Christian Lønstad wrote:
>>>> I may have gotten this wrong, but should not the device tree be passed over to ATF which again pass it over to Optee?
>>>> 
>>>> The bl31() wrapper in imx8m_atf_start_bl31 should do this using register call parameters?
>>> 
>>> I am using a quite antiquated imx-atf v2.4 and optee-os-3.2.0.imx in my setup and
>>> haven't come around to update them. I know that barebox works fine with newer TF-A
>>> versions (especially after https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/16370),
>>> but I haven't tested a newer OP-TEE, so if your OP-TEE configuration/version expects
>>> a device tree, this may indeed be the culprit.
>>> 
>>>>> 18. okt. 2023 kl. 13:29 skrev Hans Christian Lønstad <hcl at datarespons.no>:
>>>>> 
>>>>> We have a 2GB IMX8MP system using 32MB OPTEEE_SIZE, so expect to find Optee blob at 0xBE000000.
>>>>> 
>>>>> ATF compiled with:
>>>>> make PLAT=imx8mp BL32_BASE=0xBE000000 IMX_BOOT_UART_BASE=0x30890000 SPD=opteed DEBUG=1 -j
>>>>> 
>>>>> Optee compiled with:
>>>>> 
>>>>> CFG_DDR_SIZE ?= UL(0x80000000)
>>>>> CFG_UART_BASE ?= UART2_BASE
>>>>> CFG_TZDRAM_START ?= 0xBE000000
>>>>> undefine CFG_NS_ENTRY_ADDR
>>>>> 
>>>>> Barebox compiled with:
>>>>> CONFIG_HAVE_OPTEE=y CONFIG_OPTEE_SIZE=0x02000000 # CONFIG_BOOTM_OPTEE is not set CONFIG_PBL_OPTEE=y CONFIG_FIRMWARE_IMX8MP_OPTEE=y
>>> 
>>> barebox configuration looks ok assuming board code calls imx8mp_load_and_start_image_via_tfa().
>>> 
>>>>> 
>>>>> This produces the following on boot:
>>>>> —————————————————><--------------
>>>>> 
>>>>> Uart initialized
>>>>> Run level 3
>>>>> Init power
>>>>> Init DDR
>>>>> Handover to ATF
>>>>> imx8mp_load_and_start_image_via_tfa: Expect OPTEE at 0xbe000000
>>>>> CH e2a7175151fe3e842116990e62c864334e1bb030ca146b749d8e6b0c02481357
>>>>> IH e2a7175151fe3e842116990e62c864334e1bb030ca146b749d8e6b0c02481357
>>>>>                                                                 NOTICE:  Do not release JR0 to NS as it can be used by HAB
>>>>> NOTICE:  BL31: v2.8(debug):lf-6.1.36-2.1.0-0-g1a3beeab6-dirty
>>>>> NOTICE:  BL31: Built : 13:14:09, Oct 18 2023
>>>>> INFO:    GICv3 with legacy support detected.
>>>>> INFO:    ARM GICv3 driver initialized in EL3
>>>>> INFO:    Maximum SPI INTID supported: 191
>>>>> INFO:    BL31: Initializing runtime services
>>>>> INFO:    bl31_plat_get_next_image_ep_info: want image 0
>>>>> INFO:    bl31_plat_get_next_image_ep_info: bl32 PC is 0xbe000000
>>>>> INFO:    BL31: cortex_a53: CPU workaround for 855873 was applied
>>>>> WARNING: BL31: cortex_a53: CPU workaround for 1530924 was missing!
>>>>> INFO:    BL31: Initializing BL32
>>>>> INFO:    bl31_plat_get_next_image_ep_info: want image 0
>>>>> INFO:    bl31_plat_get_next_image_ep_info: bl32 PC is 0xbe000000
>>>>> INFO:    opteed_init: 176 - calling <opteed_synchronous_sp_entry>
>>>>> INFO:    opteed_synchronous_sp_entry: 79 - calling <opteed_enter_sp>
>>> 
>>> Try compiling op-tee with CFG_TEE_CORE_LOG_LEVEL=4 and see how far it gets.
>>> 
>>>>> I´m not sure why it asks for the same image twice and if this implies anything …
>>> 
>>> No idea..
>>> 
>>> Cheers,
>>> Ahmad
>>> 
>>> -- 
>>> 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 |




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