• V3s (Lichee Pi Zero)
• H3 (Orange Pi PC)
• H5 (Orange Pi PC2)
• H616 (Orange Pi Zero2)
• H6 (Orange Pi One Plus)
• R40/A40/V40 (Banana Pi BPI-M2 Berry)
• T113-S3 (MangoPi MQ-R)

IAR allows out-of-the-box execution of debuggee code in SUNXI SRAM by selecting the proper core and using a compatible linker configuration. To run code in DRAM, it must be initialized first.

This package enables step-by-step debugging in DRAM using J-Link or a compatible JTAG emulator. It was done by porting the U-Boot clock and DRAM initialization code into an IAR macro called sunxi.mac. Initialization by executing precompiled binary is also supported.

1. Setup IAR 9.40 (for Cortex-A7 only), 9.50 and later (for both A7 and A53), J-Link, board, USB dongle (optional)
2. Clone repo: git clone --recurse-submodules https://github.com/grinux/sunxi-jtag.git
3. Open sunxi-jtag.ewp or sunxi-jtag-94.ewp for EWARM 9.40
4. In sunxi_jtag.h change CFG_SYS_UART to desired console UART
5. Build XX-dram-app target
6. For Cortex-A53 core (H5, etc.) run J-Link GDB server GUI and select Cortex-A53 core, JTAG interface, and GDB port 2331
   • Or run console version with params: -select USB=0 -device Cortex-A53 -endian little -if JTAG -speed auto -noir -LocalhostOnly -nologtofile -port 2331
7. Start debugging. If IAR asks for memory configuration, click "Use factory" button
8. If message box appears, select desired initialization mode and set it permanently in project options following the message box instructions
9. Run
10. If the USB dongle is connected, "Hello from DRAM" output appears
11. Edit linker configuration sunxi.icf to set desired code/DRAM area size
12. Enjoy running applications from DRAM without unwanted tricks

The project allows running the original U-Boot initialization code. Therefore, sunxi.mac has two working modes available to select on first load:

1. Macro initialization (supports V3s, H3, R40 only)

   • Initialization is performed by JTAG directly accessing necessary registers, then the main debuggee is loaded

2. Binary initialization

   • Initialization executable is loaded by JTAG → executed → results evaluated → main debuggee loaded

Performance between the two modes is negligible.

To use binary mode:

13. Select a suitable XX-dram-init target (e.g., V3s-dram-init, H3-dram-init)
14. In sunxi_jtag.h set CFG_SYS_INIT_DEBUG to 1 to enable console output for dram-init target
15. Build. File sunXX-YY-dram-init.hex will be generated
16. Debug if needed
17. Change the target back to XX-dram-app
18. In Options → Debugger → Extra Options add or change: --macro_param init_mode="bin"
    • This tells sunxi.mac to go into binary mode and load and run the generated hex file before the main debuggee
19. Start debugging
20. Check the debug log to verify hex file was loaded and executed properly
21. Enjoy

If you have any trouble, please open an issue here or submit a pull request.

GPL-2.0 license inherited from U-Boot. Checkout this statement about using in proprietary projects.