Loading U-Boot over JTAG - 2023.2 English

Users can load and run U-Boot over JTAG and then flash drivers in the U-Boot to program the flash.

Script to run U-Boot and download the binary file for programming to flash.

• Zynq:

  # Connect to target
  connect
  
  # Load and run FSBL
  targets -set -nocase -filter {name =~ "ARM*#0"}
  dow zynq_fsbl.elf 
  con
  after 3000
  stop
  
  # Load DTB at 0x100000
  dow -data system.dtb 0x100000
  
  # Download and run u-boot 
  dow uboot.elf
  con
  after 1000; 
  stop
  
  # Download the BOOT.bin (file to program to flash) in some DDR location which is not used for other apps.
  dow -data BOOT.BIN <ddr_addr>
  

• AMD Zynq™ MP:

  # Connect to target
  connect
  
  # Disable Security gates to view PMU MB target
  targets -set -nocase -filter {name =~ "*PSU*"}
  mask_write 0xFFCA0038 0x1C0 0x1C0
  
  #Load and run PMU FW
  targets -set -nocase -filter {name =~ "*MicroBlaze PMU*"}
  dow pmufw.elf
  con
  after 500
  
  # Load and run FSBL
  targets -set -nocase -filter {name =~ "*A53*#0"}
  rst -proc
  dow zynqmp_fsbl.elf
  con
  after 5000
  stop
  
  # Load DTB at 0x100000
  dow -data system.dtb 0x100000
  
  # Load and run u-boot
  dow u-boot.elf
  dow bl31.elf
  con
  after 5000
  stop
  
  # Download the BOOT.bin (file to program to flash) in some DDR location which is not used for other apps.
  dow -data BOOT.BIN <ddr_address>
  

• Versal:

  # Connect to target
  connect
  
  # Configure the device with PDI containing PLM, necessary CDOs, u-boot, BL31 and system.dtb
  # Steps for creating this PDI (BOOT.BIN) are given in the next section 
  targets -set -nocase -filter {name =~ "*PMC*"}
  device program BOOT.BIN 
  
  # Download the BOOT.bin (file to program to flash) in some DDR location which is not used for other apps.
  targets -set -nocase -filter {name =~ "*A72*#0"}
  stop 
  dow -data BOOT.BIN <ddr_address>
  
  

  Following are the steps to create BOOT.BIN used in the script:

  1. Extract the PDI from the XSA - lets call it system.pdi
  2. Create a BIF as shown below: bootimage.bif

     all:
     {
         image
         {
             { type = bootimage, file = system.pdi }
         }
         image
         {
             name=default_subsys, id=0x1c000000
             { load = 0x1000, file = system.dtb }
             { core = a72-0, exception_level = el-3, trustzone, file = bl31.elf }
             { core = a72-0, exception_level = el-2, load=0x8000000, file=u-boot.elf }
         }
     } 

  3. Use Bootgen to create a new extended PDI by appending system.dtb, U-Boot and bl31 to the PDI extracted from XSA Bootgen -arch versal -image bootimage.bif -w -o BOOT.BIN.

Running U-Boot commands for flash programming

sf probe 0 0 0
sf erase 0 <size of BOOT.bin>
sf write <ddr_address> 0 <size of BOOT.bin>