Booting from eMMC

1. Intention will be to flash the boot0 partition with R5 SPL, A72 SPL, A72 u-boot and sysfw.itb and then flash the user partition with a tiny file system.

2. We use tiny fs right now as the full file system will take a lot of time to flash using JTAG.

3. Follow the below steps to acheive the above. Note that some commands need to run on TARGET (u-boot prompt) and some on HOST PC.

4. Physical connections needed:

   • MCU UART
   • JTAG (XDS110/XDS560v2)

5. Softwares required:

   • UNIFLASH: https://www.ti.com/tool/UNIFLASH
   • CCS: https://software-dl.ti.com/ccs/esd/documents/ccs_downloads.html

Modified eMMC layout for boot0

Each sector is 512B

				boot0 partition (4 MB)                       user partition
		 0x0+----------------------------------+    0x0+-------------------------+
			|     tiboot3.bin (384 KB)         |       |                         |
	   0x300+----------------------------------+       |                         |
			|       tispl.bin (768 KB)         |       |                         |
	   0x900+----------------------------------+       |        rootfs           |
			|       u-boot.img (2 MB)          |       |                         |
	  0x1900+----------------------------------+       |                         |
			|       sysfw.itb (768 KB)         |       |                         |
	  0x1F00+----------------------------------+       +-------------------------+

Step1: Patch the u-boot

The u-boot needs to be patched to change the offsets for the eMMC. Reason being that the eMMC part on the EVM has 8MB boot0 partition

Modify the offsets according to the layout above.

1. Apply the patch 0001-Change-the-offsets-for-eMMC-8MB-boot0-partition-to-4.patch

    cd <PATH_TO_UBOOT_DIR>
    git am 0001-Change-the-offsets-for-eMMC-8MB-boot0-partition-to-4.patch
    make mrproper
   

2. Rebuild the u-boot and SPL

    # use the top level makefile to build u-boot and SPL
    cd <PATH_TO_SDK>
    make u-boot-a53_clean -sj
    make u-boot-a53
    make u-boot-r5_clean -sj
    make u-boot-r5
   

3. Path to binaries

    ls -la <PATH_TO_SDK>/board-support/u-boot_build/r5/tiboot3.bin
    ls -la <PATH_TO_SDK>/board-support/u-boot_build/a53/tispl.bin
    ls -la <PATH_TO_SDK>/board-support/u-boot_build/a53/u-boot.img
    ls -la <PATH_TO_SDK>/board-support/prebuilt-images/sysfw.itb
   
    # Now copy these 4 binaries to <FULL_PATH_TO_BINS>
   

Step2: Flashing the eMMC boot0

Refer http://downloads.ti.com/jacinto7/esd/processor-sdk-rtos-jacinto7/latest/exports/docs/pdk_jacinto_07_00_00/docs/userguide/board/uniflash.html#getting-started-with-uniflash for more details.

UNIFLASH Commands to flash to eMMC boot0 partition (restricted to 4MB):

UNIFLASH uses actual byte offsets rather than sector offsets.

1. Change boot mode on the board to UART boot mode.
2. Close the MCU UART (2nd instance, phyically un-plug & plug back in case of windows)
3. Use below commands to flash the boot0 binaries.

Below commands run on the HOST

dslite.bat --mode processors -c COM7 -f C:\ti\uniflash_5.3.1\processors\FlashWriter\j721e_evm\uart_j721e_evm_flash_programmer_release.tiimage -i 0
dslite.bat --mode processors -c COM7 -f <FULL_PATH_TO_BINS>\tiboot3.bin -d 4 -o 0
dslite.bat --mode processors -c COM7 -f <FULL_PATH_TO_BINS>\tispl.bin -d 4 -o 60000
dslite.bat --mode processors -c COM7 -f <FULL_PATH_TO_BINS>\u-boot.img -d 4 -o 120000
dslite.bat --mode processors -c COM7 -f <FULL_PATH_TO_BINS>\sysfw.itb -d 4 -o 320000

1. Change the boot mode to eMMC boot mode and you should be able to u-boot prompt.

Step3: Setup u-boot environment

Halt at u-boot prompt and run the below commands on the TARGET

setenv mmcdev 0
setenv bootpart 0
saveenv
gpt write mmc 0 ${partitions}
mmc partconf 0 1 1 1
mmc bootbus 0 2 0 0

Step4: Flash the eMMC rootfs

Step a is optional, if you use the attached tisdk-tiny-image.tar.xz then you can stip step a

a. Create the tisdk-tiny-image.tar.xz

git clone git://arago-project.org/git/projects/oe-layersetup.git tisdk
cd tisdk/

# Copy config file from the 7.00 installer yocto-build/configs/psdkla/psdkla-07_00_00.txt
./oe-layertool-setup.sh -f psdkla-07_00_00.txt

# export proxy
export ftp_proxy=<a href="webproxy.ext.ti.com:80">http:/.../a>
export http_proxy=<a href="webproxy.ext.ti.com:80">http:/.../a>
export https_proxy=<a href="webproxy.ext.ti.com:80">http:/.../a>

cd build
# Edit config file if you want to reuse downloads folder
vi conf/local.conf
. conf/setenv

# this is the path to the toolchains for ARMv7 and ARMv8
TOOLCHAIN_BASE=/sdk/tools MACHINE=j7-evm bitbake -k tisdk-tiny-image

# build image can be found here
la -la tisdk/build/arago-tmp-external-arm-glibc/deploy/images/j7-evm/tisdk-tiny-image-j7-evm.tar.xz

b. Create a tiny rootfs image from the tisdk-tiny-image.tar.xz (attached)

Below steps need to be run on HOST machine to create the tisdk-tiny-image.img

# Create an empty image file, seek value will create an image of that size. Typically 100MB should be enough.
# Size will should be slightly greater than size of untarred tisdk-tiny-image-j7-evm.tar.xz + size (DTBs + Kernel image)
dd if=/dev/null of= bs=1M seek=100

# Add a filesystem to it
mkfs.ext4 -F tisdk-tiny-image.img

# Mount it on your local machine to copy DTB and Kernel image
mkdir example_mnt_pt
sudo mount -t ext4 -o loop tisdk-tiny-image.img /home/karan/yocto-build/example_mnt_pt

# Untar tisdk-tiny-image-j7-evm.tar.xz on the mounted file system which is currently empty
cd example_mnt_pt
sudo tar xvf ../tisdk-tiny-image-j7-evm.tar.xz

# Copy DTB, DTBOs and Kernel Image for your platform
sudo cp /media/karan/rootfs/boot/Image* example_mnt_pt/boot
sudo cp /media/karan/rootfs/boot/*dtb* example_mnt_pt/boot
sync

# Unmount the image, now the tisdk-tiny-image.img is ready
cd ../
sudo umount /home/karan/yocto-build/example_mnt_pt

# Now you have the tisdk-tiny-image.img ready  to be flashed.

c. Flash this tisdk-tiny-image.img using JTAG + u-boot

Do NOT power cycle throught this step

1. Halt at u-boot

2. Connect CCS using the XDS110/XDS560v2 and using the appropriate target ccxml (without GELs).

3. Load the tisdk-tiny-image.img to the DDR address 0x80080000

   • Launch the target ccxml and connect to CortexA72_0_0
   • Open Memory browser and load memory: View -> Memory Browser -> Load Memory
   • Select file tisdk-tiny-image.img and select File Type as Binary, click Next
   • Set Start Address as 0x80080000, click Finish.

     Depending on the JTAG used the time taken to load this will vary. Expect 1Hr with XDS110 and 20mins with XDS560v2.

4. Now the image in loaded on the RAM, flash it using u-boot

   Code runs at u-boot prompt on the TARGET

    part start mmc 0 rootfs
    
    # what ever the above command outputs, use that below (eg - 0x22)
    mmc write 0x80080000 0x22 0x32000
   
    # after the above completes
    boot
   

With this you should be able to boot to the tiny file system in eMMC.

Package: /cfs-file/__key/communityserver-discussions-components-files/791/eMMC_5F00_flashing_5F00_package.zip

Regards,

Karan