OpenOCD fails to read peripheral memory via sysbus/progbuf/abstract when using PlatformIO SVD view

I’m working with a custom RISC-V 64-bit SoC. The PlatformIO support for this SoC is still under development, and I am part of the team building that integration.

As part of testing, I created an SVD file for this SoC and configured PlatformIO to use it (debug_svd_path). When I start a debug session:

• All peripherals appear in the debug view.
• A temporary breakpoint is correctly set at main().
• OpenOCD is running externally (started manually in another terminal).
• PlatformIO is configured to connect using a custom debug tool.

However, whenever PlatformIO tries to update peripheral registers, OpenOCD reports memory read failures.

In the PlatformIO debug console, I see:

Internal error: Failed to update peripheral UART0 after memory reads

Whenever I try to step in or step out of the code in VS Code, OpenOCD fails with the same error. In the OpenOCD log, I see:

Error: [riscv.cpu.0] Failed to read memory (addr=0x11300)
 progbuf=disabled, sysbus=skipped (sysbus access failed), abstract=disabled

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Environment

• OpenOCD: official upstream build

• OpenOCD launch command:

  openocd -f interface/jtag.cfg -f target/riscv.cfg
  

• PlatformIO platformio.ini:

  [env:secure-iot]
  platform = mg
  board = secure-iot
  framework = Apps
  monitor_speed = 115200
  monitor_port = /dev/ttyUSB1
  debug_svd_path = path/to/Secure_IoT.svd
  upload_protocol = ft2232
  debug_speed = 1000
  debug_tool = custom
  debug_port = localhost:3333
  
  debug_build_flags = -O0 -ggdb3 -g3
  build_type = debug
  
  ; Override GDB init sequence
  debug_extra_cmds =
      monitor halt
  

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Logs

From OpenOCD:

Warn : [riscv.cpu.0] Failed to read memory via system bus.
Error: [riscv.cpu.0] Failed to read memory (addr=0x60100)
  progbuf=disabled, sysbus=skipped (sysbus access failed), abstract=disabled
Error: [riscv.cpu.0] Failed to read memory (addr=0x20100)
  progbuf=disabled, sysbus=skipped (sysbus access failed), abstract=disabled
Error: [riscv.cpu.0] Failed to read memory (addr=0x11300)
  progbuf=disabled, sysbus=skipped (sysbus access failed), abstract=disabled
(repeats for multiple addresses)

From PlatformIO:

PlatformIO: Initialization completed
Internal error: Failed to update peripheral OTP after memory reads
Internal error: Failed to update peripheral UART0 after memory reads
PlatformIO: Resume the execution to `debug_init_break = tbreak main`

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Important Observation

Manual memory reads in GDB do succeed, for example:

(gdb) x/x 0x11300
0x11300:  0x017c017c

So the hardware can return values from memory, but OpenOCD reports that progbuf, sysbus, and abstract access are all disabled/skipped when peripheral polling is triggered from PlatformIO.

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Hardware

• SoC: Custom RISC-V 64-bit
• Debug module: supports progbuf, sba, and abstract (expected to be available)

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Steps to Reproduce

1. Start OpenOCD with:

   openocd -f interface/jtag.cfg -f target/riscv.cfg
   

2. Launch a debug session in PlatformIO with the platformio.ini shown above.

3. Observe that peripherals are listed, but peripheral register updates fail.

4. Compare with manual GDB access (x/x <addr>) which works.

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Question

• Is this an OpenOCD limitation or a configuration issue on my side?
• Why does manual memory access via GDB succeed, but automatic peripheral polling through OpenOCD fails?