IMX8M and Optee support

[Hans Christian Lønstad]

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.

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
> 
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