AMP Debugging
Debugging and troubleshooting
12.1 Recommended debug sequence
- Boot only RTOS/HAL and verify the entry address, linker address, and debug UART.
- Add Linux without RPMsg and verify that both sides start reliably.
- Check
/proc/iomem, DTS reserved memory, and the linked address ranges of every ELF file. - Enable Mailbox/SoftIRQ and RPMsg, and run the SDK demo first.
- Transfer actual peripherals and application code one resource type at a time.
Useful Linux-side checks:
cat /proc/iomem
cat /proc/interrupts
dmesg | grep -Ei 'amp|rpmsg|virtio|mailbox|reserved|failed|error'
ls /sys/firmware/devicetree/base/reserved-memory/Inspect the entry point and segments of an RTOS/HAL ELF file:
<cross-readelf> -h <firmware>.elf
<cross-readelf> -l <firmware>.elf
<cross-nm> -n <firmware>.elf | head12.2 Common issues
| Symptom | Common cause | Resolution |
|---|---|---|
U-Boot does not print Brought up cpu | U-Boot was not built with rk-amp.config, the amp partition is missing, or FIT validation failed | Check the U-Boot configuration, partition table, amp.img, and loadables |
| Remote core faults immediately after startup | ITS load does not match the linked address, or the firmware exceeds its assigned region | Compare the ITS, map file, ELF program headers, and DTS |
| Linux crashes intermittently or data is corrupted | Remote-core memory is not reserved in Linux or overlaps CMA/another reserved region | Check reserved-memory, /proc/iomem, and the actual DDR capacity |
| RTOS/HAL has no serial output | UART is owned by Linux, the IOMUX group is wrong, the clock is not retained, or the baud rate differs | Disable the Linux UART node and check AMP clocks/pinctrl and board IOMUX |
| A peripheral works in polling mode but not with interrupts | GIC/NVIC/IPIC routing is wrong, or the peripheral interrupt source is disabled | Check the interrupt ID, target CPU, ISR, and peripheral registers in sequence |
RPMsg only reports host is online | The remote is not running, shared addresses differ, or Name Service was not announced | Check remote logs, vring addresses, link ID, and endpoint name |
| RPMsg occasionally loses messages or hangs | Cache attributes differ, shared memory overlaps another region, or memory barriers are missing | Restore the SDK's default uncached configuration and check MMU/MPU mappings |
/dev/ttyRPMSG* is missing | CONFIG_RPMSG_TTY is disabled or the remote did not announce rpmsg-tty | Check the Kernel configuration and remote Name Service |
| A newly assigned peripheral fails in both Linux and RTOS | Both sides still manage the peripheral, pinctrl, reset, or clock | Establish a single owner, disable the Linux DTS device, and retain required resources through the AMP node |
12.3 JTAG debugging
- Cortex-A RTOS/HAL firmware can be debugged with OpenOCD and JTAG by loading the ELF symbols for the corresponding CPU.
- A Cortex-M MCU can be debugged with J-Link/Ozone using connection scripts and address mappings designed for the target SoC.
- The ELF loaded into the debugger must come from the same build as the
amp.imgcurrently running on the board.