[Info] Enable the LP core of BL808 and receive "Hello world" msg from LP core

[cjacker]

Update: too quick response from upstream developer, my work already upstreamed.

Here is a demo 'tripplecore' for it: https://github.com/cjacker/opensource-toolchain-bouffalo-lab/tree/main/triplecore_bl808

Install XuanTie RISC-V toolchain

wget https://occ-oss-prod.oss-cn-hangzhou.aliyuncs.com/resource//1663142243961/Xuantie-900-gcc-elf-newlib-x86_64-V2.6.1-20220906.tar.gz
sudo mkdir -p /opt/xuantie-riscv64-embed-toolchain
sudo tar xf Xuantie-900-gcc-elf-newlib-x86_64-V2.6.1-20220906.tar.gz -C /opt/xuantie-riscv64-embed-toolchain --strip-components=1

And add /opt/xuantie-riscv64-embed-toolchain/bin to PATH env according to your shell.

Apply patch to bl_mcu_sdk

Update: it's already upstreamed.

Build this triplecore demo

Enter 'bl_mcu_sdk/examples/bl808_triplecore' dir and type make directly.

After build successfully, these firmware files will be generated:

• ./helloworld_m0/build/build_out/helloworld_bl808_m0.bin : firmware for m0
• ./helloworld_lp/build/build_out/helloworld_bl808_lp.bin : firmware for lp
• ./helloworld_d0/build/build_out/helloworld_bl808_d0.bin : firmware for d0

Program to bl808

Since BLDevCube GUI tool not support Group2 in BL808 MCU page, you can not program these firmwares in one time.

I suggest to program it one by one by BLFlashCommand, you may need to activate UART programming mode every time.

Here use Sipeed M1S Dock as example.

• Connect 'UART' TypeC port of M1S Dock to PC USB port.
• Hold 'BOOT' down and press 'RESET' button.
• Release 'RESET' button, then release 'BOOT' button.

M1S Dock will enter UART programming mode.

Then:

cd helloworld_m0
make flash

After programmed, you need re-power M1S Dock and continue programming firmwares for d0 and lp core as above steps.

Wire up USB2TTL adapters

After all three firmware programmed, Wire 3 USB2TTL adapter as:

• UART0 for D0 core

  • GPIO 14 (TX) -> USB2TTL RX
  • GPIO 15 (RX) -> USB2TTL TX

• UART1 for M0 core

  • GPIO 16 (TX) -> USB2TTL RX
  • GPIO 17 (RX) -> USB2TTL TX

• UART2 for LP core

  • GPIO 18 (TX) -> USB2TTL RX
  • GPIO 19 (RX) -> USB2TTL TX

For M1S Dock, since it already have 2 UARTs (emulated by BL702) connect to D0 and M0, you only need wire another USB2TTL adapter to GPIO 18 and GPIO 19 for LP core.

For my env, the 3 serial devices are :

• '/dev/ttyUSB0' for D0
• '/dev/ttyUSB1' for M0
• '/dev/ttyACM0' for LP

Check it according to your env.

Receive hello world from 3 cores

Use any serial terminal such as tio / minicom / picocom / cutecom, etc. Set baudrate to 2000000, 8N1, and open 3 serial devices.

You will receive "hello world" from 3 cores.

To restore factory firmwares for Sipeed M1S Dock

Use these scripts and firmware to restore the factory firmwares for Sipeed M1S Dock:

https://github.com/cjacker/opensource-toolchain-bouffalo-lab/tree/main/m1s_dock_factory_firmware

More

• GPIO 18 (TX) and GPIO 19 (RX) for LP core UART is defined in bsp/board/bl808dk/board.c, you can change it as you like.

• LP core is boot by M0 core, and boot from 0x58020000, FW addr set to 0x20000 in helloworld_lp/flash_prog_cfg.ini for BLFlashCommand

[sakumisu]

Hi, @cjacker thank you for your effort, you do the same code as mine, could you please pr this patch into master?

[cjacker]

OK, I will send a PR.

[cjacker]

By the way, could you update BLDevCube for various platforms to add 'Group2' support to MCU page? After that, these firmwares can be programmed in one time.

[Fishwaldo]

There still is a issue with overlapping RAM regions in the linker scripts for M0/LP

If M0 uses more than 16K ram, it will walk over the memory for LP

[sakumisue]

There still is a issue with overlapping RAM regions in the linker scripts for M0/LP

If M0 uses more than 16K ram, it will walk over the memory for LP

This depends on user code, it is variable.