J722S-EVM Platform

The J722S is a family of application processors built for Automotive and Linux Application development. J722S family of SoCs is a superset of the AM62P SoC family and shares similar memory map, thus the nodes are being reused from AM62P includes instead of duplicating the definitions.

Some highlights of J722S SoC (in addition to AM62P SoC features) are:

Two Cortex-R5F for Functional Safety or general-purpose usage and two C7x floating point vector DSP with Matrix Multiply Accelerator for deep learning.
Vision Processing Accelerator (VPAC) with image signal processor and Depth and Motion Processing Accelerator (DMPAC).
7xUARTs, 3xSPI, 5xI2C, 2xUSB2, 2xCAN-FD, 3xMMC and SD, GPMC for NAND/FPGA connection, OSPI memory controller, 5xMcASP for audio, 4xCSI-RX for Camera, 1 PCIe Gen3 controller, USB3.0 eCAP/eQEP, ePWM, among other peripherals.

For those interested, more details about this SoC can be found in the Technical Reference Manual here: https://www.ti.com/lit/zip/sprujb3

Boot Flow:

The bootflow is exactly the same as all SoCs in the am62xxx extended SoC family. Below is the pictorial representation:

Here TIFS acts as master and provides all the critical services. R5/A53 requests TIFS to get these services done as shown in the above diagram.

Sources:

Das U-Boot

source: https://source.denx.de/u-boot/u-boot.git

branch: master
Trusted Firmware-A (TF-A)

source: https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/

branch: master
Open Portable Trusted Execution Environment (OP-TEE)

source: https://github.com/OP-TEE/optee_os.git

branch: master
TI Firmware (TIFS, DM, SYSFW)

source: https://github.com/TexasInstruments/ti-linux-firmware

branch: ti-linux-firmware

Note

The TI Firmwares required for functionality of the system are (see platform specific boot diagram for further information as to which component runs on which processor):

TIFS - TI Foundational Security Firmware - Consists of purely firmware meant to run on the security enclave.
DM - Device Management firmware also called TI System Control Interface server (TISCI Server) - This component purely plays the role of managing device resources such as power, clock, interrupts, dma etc. This firmware runs on a dedicated or multi-use microcontroller outside the security enclave.

Build procedure:

Setup the environment variables:

Generic environment variables
S/w Component	Env Variable	Description
All Software	CC32	Cross compiler for ARMv7 (ARM 32bit), typically arm-linux-gnueabihf-
All Software	CC64	Cross compiler for ARMv8 (ARM 64bit), typically aarch64-linux-gnu-
All Software	LNX_FW_PATH	Path to TI Linux firmware repository
All Software	TFA_PATH	Path to source of Trusted Firmware-A
All Software	OPTEE_PATH	Path to source of OP-TEE

Board specific environment variables
S/w Component	Env Variable	Description
U-Boot	UBOOT_CFG_CORTEXR	Defconfig for Cortex-R (Boot processor).
U-Boot	UBOOT_CFG_CORTEXA	Defconfig for Cortex-A (MPU processor).
Trusted Firmware-A	TFA_BOARD	Platform name used for building TF-A for Cortex-A Processor.
Trusted Firmware-A	TFA_EXTRA_ARGS	Any extra arguments used for building TF-A.
OP-TEE	OPTEE_PLATFORM	Platform name used for building OP-TEE for Cortex-A Processor.
OP-TEE	OPTEE_EXTRA_ARGS	Any extra arguments used for building OP-TEE.

Set the variables corresponding to this platform:

export CC32=arm-linux-gnueabihf-
export CC64=aarch64-linux-gnu-
export LNX_FW_PATH=path/to/ti-linux-firmware
export TFA_PATH=path/to/trusted-firmware-a
export OPTEE_PATH=path/to/optee_os

export UBOOT_CFG_CORTEXR=j722s_evm_r5_defconfig
export UBOOT_CFG_CORTEXA=j722s_evm_a53_defconfig
export TFA_BOARD=lite
export OPTEE_PLATFORM=k3-am62x

Trusted Firmware-A:

# inside trusted-firmware-a source
make CROSS_COMPILE=$CC64 ARCH=aarch64 PLAT=k3 SPD=opteed $TFA_EXTRA_ARGS \
     TARGET_BOARD=$TFA_BOARD

OP-TEE:

# inside optee_os source
make CROSS_COMPILE=$CC32 CROSS_COMPILE64=$CC64 CFG_ARM64_core=y $OPTEE_EXTRA_ARGS \
      PLATFORM=$OPTEE_PLATFORM

U-Boot:

3.1 R5:

# inside u-boot source
make $UBOOT_CFG_CORTEXR
make CROSS_COMPILE=$CC32 BINMAN_INDIRS=$LNX_FW_PATH

3.2 A53:

# inside u-boot source
make $UBOOT_CFG_CORTEXA
make CROSS_COMPILE=$CC64 BINMAN_INDIRS=$LNX_FW_PATH \
       BL31=$TFA_PATH/build/k3/$TFA_BOARD/release/bl31.bin \
       TEE=$OPTEE_PATH/out/arm-plat-k3/core/tee-raw.bin

Note

It is also possible to pick up a custom DM binary by adding TI_DM argument pointing to the file. If not provided, it defaults to picking up the DM binary from BINMAN_INDIRS. This is only applicable to devices that utilize split firmware.

Target Images

In order to boot we need tiboot3.bin, tispl.bin and u-boot.img. Each SoC variant (HS-FS, HS-SE) requires a different source for these files.

HS-FS

tiboot3-j722s-hs-fs-evm.bin from step 3.1

tispl.bin, u-boot.img from step 3.2

HS-SE

tiboot3-j722s-hs-evm.bin from step 3.1

tispl.bin, u-boot.img from step 3.2

Image formats:

tiboot3.bin

tispl.bin

A53 SPL DDR Memory Layout

This provides an overview memory usage in A53 SPL stage.

Region	Start Address	End Address
EMPTY	0x80000000	0x80080000
TEXT BASE	0x80080000	0x800d8000
EMPTY	0x800d8000	0x80477660
STACK	0x80477660	0x80477e60
GD	0x80477e60	0x80478000
MALLOC	0x80478000	0x80480000
EMPTY	0x80480000	0x80a00000
BSS	0x80a00000	0x80a80000
BLOBS	0x80a80000	0x80d00400
EMPTY	0x80d00400	0x81000000

Switch Setting for Boot Mode

Boot Mode pins provide means to select the boot mode and options before the device is powered up. After every POR, they are the main source to populate the Boot Parameter Tables.

The following table shows some common boot modes used on J722S-EVM platform. More details can be found in the Technical Reference Manual: https://www.ti.com/lit/zip/sprujb3 under the Boot Mode Pins section.

Boot Modes
Switch Label	SW3: 12345678	SW4: 12345678
SD	11000010	01000000
OSPI	11001110	00000000
EMMC	11010010	00000000
UART	11011100	00000000
USB DFU	11001010	00000000

For SW2 and SW1, the switch state in the “ON” position = 1.

Debugging U-Boot

See Common Debugging environment - OpenOCD: for detailed setup information.

Warning

OpenOCD support after: v0.12.0

While support for the entire K3 generation including the am62xxx extended family was added before v0.12.0, the tcl scripts for the am62px have been accepted and will be available in the next release of OpenOCD. It may be necessary to build OpenOCD from source depending on the version your distribution has packaged.

Integrated JTAG adapter/dongle: The board has a micro-USB connector labelled XDS110 USB or JTAG. Connect a USB cable to the board to the mentioned port.

Note

There are multiple USB ports on a typical board, So, ensure you have read the user guide for the board and confirmed the silk screen label to ensure connecting to the correct port.

To start OpenOCD and connect to the board

openocd -f board/ti_j722sevm.cfg