Debug TI Keystone II UBoot with CCSv 5

Debug TI Keystone II U-Boot with CCSv 5 Vincent Han Mar, 2014 TI Information – Selective Disclosure 1

Agenda • Basic U-boot Code Structure • Debug on TCI 6638 EVM with CCSv 5 TI Information – Selective Disclosure 2

Basic Keystone II U-boot Code Structure TI Information – Selective Disclosure

U-boot Relocation Mechanism • U-boot designs the HW initialization as 2 parts – 1 st part is function “board_init_f” – 2 nd part is function “board_init_r” • There will be sections’ relocation operation during these 2 steps • Benefits of this design: – Can implement on some platforms have little on-chip SRAM to run entire image (e. g. have little size of on-chip memory but have enough room on DDR) – Can improve the code execute efficiency (e. g. first run on Flash then relocate the code and run on SRAM) • Although Keystone II devices have enough on-chip SRAM , the Keystone II U-boot code still keeps this mechanism TI Information – Selective Disclosure

U-boot Relocation Procedures - 1 TI Information – Selective Disclosure

U-boot Relocation Procedures - 2 TI Information – Selective Disclosure

U-boot Relocation Procedures - 3 TI Information – Selective Disclosure

Agenda • Basic U-boot Code Structure • Debug on TCI 6638 EVM with CCSv 5 TI Information – Selective Disclosure 8

Debug on TCI 6638 EVM with CCSv 5 • Launch the debug session and connect the target – Please do not use any ARM core gel file – Connect with the 1 st ARM core on TCI 6638 (other 3 cores are power-off after reset) • Load symbol to the target – After you load the symbol table, some of the symbols/functions which defined in U-boot image can be recognized by CCS • Load bin file to the target – Choose the load address “ 0 x 0 C 00_1000” and choose the 32 -bit load mode • Change PC and map code in CCS – Add PC pointer in expression view and force PC pointer point to “ 0 x 0 C 00_1000” – Step into/over in the disassembly view by clicking green buttons until the PC pointer point to “board_init_f” TI Information – Selective Disclosure

Debug on TCI 6638 EVM with CCSv 5 – Click “step into” to go to this function, you will see the following hints in code view window – Click “Locate File” to locate the correct path of board. c on your PC – Then you can debug the first part of hardware configurations code calling in function “board_init_f” • Get the relocate address from code – Function “board_init_f” will calculate the relocation address and store it in “id>relocaddr”, we can get this value in the end part of this function • Remap code in CCS for relocation – After the relocation, the disassembly pointer and source code pointer will not be match with each other, which need our manually adjust to correct offset – We need to run just before calling “relocate_code” in function “_main” by setting the hardware breakpoint TI Information – Selective Disclosure

Debug on TCI 6638 EVM with CCSv 5 – Then reload the symbol by adding the previous offset “ 0 x. BFF 5_6000” to get the correct source code and disassembly pointer after the relocation for further debugging – The code and disassembly pointer will adjust to the correct place after relocation – We can switch to the correct address of “board_init_r” and make a hardware breakpoint in that place, then execute the code to stop at that breakpoint – We need to make the breakpoint at the adjusted address rather than the address before the relocation, or the breakpoint to the different place and cannot stop correctly – We can see that after we stopped after relocation, the assembly code seemed incorrect due to the CCS disassembly view window parse the code in 32 -bit ARM mode other than 16 -bit Thumb mode, which needs us manually change the disassembly code view to Thumb mode – After this step, you can move on to debug the U-boot code in CCS by step into/over • For more information, please refer operation guide on deyisupport TI Information – Selective Disclosure

Boot Linux Kernel (UBI File-system) • For the next boot procedure, if you configured the environment variables correctly, U-Boot will boot Linux Kernel automatically by default. • Using UBI file-system, Linux Kernel, Boot Monitor and DTB files will be burnt on NAND flash, Ethernet is not needed during every boot time. TI Information – Selective Disclosure 12

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