AM6254ATL SIP Platforms
Introduction:
The AM6254atl SiP (System In Package) provides existing AM62 Platforms with 512MiB of DDR integrated in a single packages.
More details can be found in the Technical Reference Manual: https://www.ti.com/lit/pdf/spruiv7
Platform information:
Boot Flow:
Below is the pictorial representation of boot flow:
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
branch: masterTrusted Firmware-A (TF-A)
branch: masterOpen Portable Trusted Execution Environment (OP-TEE)
branch: masterTI Firmware (TIFS, DM, SYSFW)
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.
TIFS Stub - The TIFS stub is a small piece of binary designed to help restore the required security context and resume the TIFS firmware when the system resumes from low-power modes such as suspend-to-RAM/Deep Sleep. This stub uses the same encryption and customer key signing model as TIFS and is loaded into the ATCM (Tightly Coupled Memory ‘A’ of the DM R5) during DM startup. Due to the independent certificate signing process, the stub is maintained separately from DM.
Build procedure:
Setup the 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 |
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=am6254atl_evm_r5_defconfig
export UBOOT_CFG_CORTEXA=am6254atl_evm_a53_defconfig
export TFA_BOARD=lite
export TFA_EXTRA_ARGS="PRELOADED_BL33_BASE=0x82000000 BL32_BASE=0x80080000"
export OPTEE_PLATFORM=k3-am62x
export OPTEE_EXTRA_ARGS="CFG_TZDRAM_START=0x80080000"
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=$LNX_FW_PATH
3.1.1 Alternative build of R5 for DFU boot:
As the SPL size can get too big when building with support for booting both from local storage and DFU an extra config fragment should be used to enable DFU support (and disable storage support)
export UBOOT_CFG_CORTEXR="${UBOOT_CFG_CORTEXR} am62x_r5_usbdfu.config"
# 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 or HS-SE) requires a different source for these files.
HS-FS
tiboot3-am62x-hs-fs-evm.bin from step 3.1
tispl.bin, u-boot.img from step 3.2
HS-SE
tiboot3-am62x-hs-evm.bin from step 3.1
tispl.bin, u-boot.img from step 3.2
Image formats:
tiboot3.bin
tispl.bin
OSPI:
ROM supports booting from OSPI from offset 0x0.
Flashing images to OSPI:
Below commands can be used to download tiboot3.bin, tispl.bin, and u-boot.img, over tftp and then flash those to OSPI at their respective addresses.
sf probe
tftp ${loadaddr} tiboot3.bin
sf update $loadaddr 0x0 $filesize
tftp ${loadaddr} tispl.bin
sf update $loadaddr 0x80000 $filesize
tftp ${loadaddr} u-boot.img
sf update $loadaddr 0x280000 $filesize
Flash layout for OSPI:
A53 SPL DDR Memory Layout
This provides an overview memory usage in A53 SPL stage.
Region |
Start Address |
End Address |
|---|---|---|
ATF |
0x80000000 |
0x80080000 |
OPTEE |
0x80080000 |
0x81880000 |
TEXT BASE |
0x81880000 |
0x818d8000 |
EMPTY |
0x818d8000 |
0x81a00000 |
BMP IMAGE |
0x81a00000 |
0x82377660 |
STACK |
0x82377660 |
0x82377e60 |
GD |
0x82377e60 |
0x80b78000 |
MALLOC |
0x82378000 |
0x82380000 |
EMPTY |
0x82380000 |
0x82480000 |
BSS |
0x82480000 |
0x82500000 |
BLOBS |
0x82500000 |
0x82500400 |
EMPTY |
0x82500400 |
0x82800000 |
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 AM62 platform. More details can be found in the Technical Reference Manual: https://www.ti.com/lit/pdf/spruiv7 under the Boot Mode Pins section.
Switch Label |
SW2: 12345678 |
SW3: 12345678 |
|---|---|---|
SD |
01000000 |
11000010 |
OSPI |
00000000 |
11001110 |
EMMC |
00000000 |
11010010 |
UART |
00000000 |
11011100 |
USB DFU |
00000000 |
11001010 |
Ethernet |
00110000 |
11000100 |
For SW2 and SW1, the switch state in the “ON” position = 1.
DFU based boot
To boot the board over DFU, set the switches to DFU mode and connect to the USB type C DRD port on the board. After power-on the build artifacts needs to be uploaded one by one with a tool like dfu-util.
The initial ROM will have a DFU alt named bootloader for the initial R5 spl upload. The next stages as exposed by U-Boot have target alts matching the name of the artifacts, for these a USB reset has to be done after each upload.
When using dfu-util the following commands can be used to boot to a U-Boot shell:
dfu-util -a bootloader -D tiboot3.bin
dfu-util -R -a tispl.bin -D tispl.bin
dfu-util -R -a u-boot.img -D u-boot.img
Debugging U-Boot
See Common Debugging environment - OpenOCD: for detailed setup information.
Warning
OpenOCD support since: v0.12.0
If the default package version of OpenOCD in your development environment’s distribution needs to be updated, it might be necessary to build OpenOCD from the source.
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_am625evm.cfg