CubeMX breaks TF-A

[AMurr.2282]

When building a custom machine for the STM32MP153AAC (using yocto), the device tree generated by CubeMX for the TF-A creates the following output:

NOTICE:  CPU: STM32MP153AAB Rev.B
NOTICE:  Model: STMicroelectronics custom STM32CubeMX board
INFO:    Reset reason (0x14):
INFO:      Pad Reset from NRST
INFO:    Using USB
INFO:      Instance 2
INFO:    Boot used partition fsbl1
NOTICE:  BL2: v2.2-r1.0(release):devtool-patched-dirty
NOTICE:  BL2: Built : 13:15:56, Sep 25 2020
INFO:    Using crypto library 'stm32_crypto_lib'
INFO:    BL2: Doing platform setup
INFO:    RAM: DDR3-DDR3L 16bits 533000Khz
INFO:    Memory size = 0x10000000 (256 MB)
INFO:    BL2 runs SP_MIN setup
INFO:    BL2: Loading image id 4
INFO:    Loading image id=4 at address 0x2ffed000
INFO:    Image id=4 loaded: 0x2ffed000 - 0x2ffff000
INFO:    BL2: Loading image id 5
INFO:    GETSTATUS :
INFO:                   DFU_STATE_IDLE
INFO:    UPLOAD :
INFO:                   Phase ID : 0
INFO:                   address 0x2ffe5928
INFO:    GETSTATUS :
INFO:                   DFU_STATE_IDLE
INFO:    GETSTATUS :
INFO:                   DFU_STATE_IDLE
INFO:    UPLOAD :
INFO:                   Phase ID : 0
INFO:                   address 0x2ffe5928
INFO:    GETSTATUS :
INFO:                   DFU_STATE_IDLE
INFO:    Start Download partition 0 to address 0xc0000000 length 0
INFO:    USB : DFU : end of download partition : 0
INFO:    Loading image id=5 at address 0xc0100000
INFO:    GETSTATUS :
INFO:                   DFU_STATE_IDLE
INFO:    UPLOAD :
INFO:                   Phase ID : 3
INFO:                   address 0x2ffe5928
INFO:    GETSTATUS :
INFO:                   DFU_STATE_IDLE
INFO:    receive request 6
INFO:    GETSTATUS :
INFO:                   DFU_STATE_IDLE
INFO:    UPLOAD :
INFO:                   Phase ID : 3
INFO:                   address 0x2ffe5928
INFO:    GETSTATUS :
INFO:                   DFU_STATE_IDLE
INFO:    usb_partition_size: partition size : 0xce9cf
INFO:    Start Download partition 3 to address 0xc0100000 length 846287
INFO:    USB : DFU : end of download partition : 3
INFO:    GETSTATUS :
INFO:                   DFU_STATE_IDLE
INFO:    UPLOAD :
INFO:                   Phase ID : 0
INFO:                   address 0xffffffff
INFO:    Send detach request
INFO:    GETSTATUS :
INFO:                   DFU_STATE_IDLE
INFO:    Receive Detach
INFO:    Image id=5 loaded: 0xc0100000 - 0xc01ce9cf
NOTICE:  BL2: Booting BL32
INFO:    Entry point address = 0x2ffed000
INFO:    SPSR = 0x1d3

This is as far as it gets. The CPU appears to hang here.

After an extremely tiring and timely process of diffing/binary searching the TF-A device tree with one that works, I have found that adding the following to the generated TF-A device tree fixes the issue:

/* USER CODE BEGIN addons */
&cpu0 {
    cpu-supply = <&v1v2_vdd_core>;
};
&cpu1 {
    cpu-supply = <&v1v2_vdd_core>;
};
/* USER CODE END addons */

Where v1v2_vdd_core is a node in the pmic section:

pmic: stpmic@33 {
    compatible = "st,stpmic1";
    /* (stuff) */
    regulators {
        v1v2_vdd_core: buck1 {
                regulator-name = "v1v2_vdd_core";
                regulator-min-microvolt = <1200000>;
                regulator-max-microvolt = <1350000>;
                regulator-always-on;
                regulator-initial-mode = <0>;
                regulator-over-current-protection;
                lp-stop {
                    regulator-on-in-suspend;
                    regulator-suspend-microvolt = <1200000>;
                };
                standby-ddr-sr {
                    regulator-off-in-suspend;
                };
                standby-ddr-off {
                    regulator-off-in-suspend;
                };
        };
 
        /* (more stuff) */
    };
};

I don't understand why this fixes it, nor do I understand why it hangs in the first place.

If you need more information I'd be happy to supply it.

[Olivier GALLIEN]

​Hi @AMurr.2282​ ,

You may know that for "sample" project as you ( STM32MP153AAC ) STM32CubeMX generate only "partial" Device Tree.

You need to fill all USER SECTION in order to get a complete and bootable Device Tree.

To help you we provide this wiki page :

https://wiki.st.com/stm32mpu/wiki/How_to_create_your_board_device_tree

+ you can use complete dts generated in case of project for DK2 or EV1 board in order to help how to fill USER SECTION

Hope it help

Olivier