[SOLVED] Select between SysBus and ProgBuf when accessing memory on RISC-V core?

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  • [SOLVED] Select between SysBus and ProgBuf when accessing memory on RISC-V core?

    Hello,

    on a RISC-V (RV32) core that supports both "Program Buffer" and "System Bus Access", I can observe that J-Link Commander (V6.50) uses System Bus to access main memory (commands mem8, mem16, ... w1, w2, ...).


    Is there an option that would select whether JLinkExe will access the memory through one or the other approach? Having this choice is very important in practice, as ProgramBuffer will always provide hart's point of view to memory, which is on the other hand not guaranteed with System Bus (depending on the system structure, presence of caches, etc.). Further rationale for this is given in the RISC-V debug spec 0.13.2, page 18, section 3.9.

    For example OpenOCD has this switch in the form of "riscv set_prefer_sba [on|off]" command which selects whether SystemBus or ProgBuf is used as the "first choice" when accessing the memory:


    If there is no such feature in J-Link Commander, would you please consider implementing it?

    Thank you,
    Jan
  • Hello Jan,

    Thank you for your inquiry.
    We received your inquiry in parallel via our Support System. To make sure no information is lost between different channels this thread will be locked now.

    Best regards,
    Nino
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