Runing pyTorch Model in STM32F749

Model:
   SINE MLP-3 Model
Toolchain:
   pyTorch + TVM/LLVM + RIOT
Procedure:
   (1) Use pyTorch to train and save model.
   (2) Use TVM to compile model and save it to C library format.
   (3) Write C file and Makefile to compile the model in RIOT OS. \

Step 1: Train and Save Sine Model in pyTorch

Training Sine Model

File: 0101trainSine.py
Info: Refer to TinyML Book Chapter 4.

# Save the trained pyTorch model weight
torch.save(model.state_dict(), 'model/sine_mlp3.pth')

Transform pyTorch Model for TVM

File: 0103scriptedpyTorch.py Info: Transform pyTorch model.

# Just-in-time compilation
input_shape = [1,1]
input_data = torch.randn(input_shape)
scripted_model = torch.jit.trace(model, input_data).eval()

scripted_model.save('model/sine_mlp3_scripted.pth')

Step 2: Compiled with TVM to Generate Library

File: 0201tvm.py
Info: .

import tvm
from tvm import relay
from tvm.relay.backend import Executor
from tvm.relay.backend import Runtime
from tvm.driver import tvmc
from tvm.micro import export_model_library_format

RUNTIME = Runtime('crt', {'system-lib':False})
EXECUTOR = Executor('aot',
    {"unpacked-api": True, 
    "interface-api": "c", 
    "workspace-byte-alignment": 4,
    "link-params": True,},
    )

TARGET = tvm.target.target.stm32('stm32F7xx')

# Build Model in TVM Relay
with tvm.transform.PassContext(opt_level=3, 
    config={"tir.disable_vectorize": True, 
    "tir.usmp.enable": True}):
    module = relay.build(model.mod, 
                        target=TARGET, 
                        runtime=RUNTIME, 
                        params=model.params, 
                        executor=EXECUTOR)

export_model_library_format(module, './models/default/default.tar')

Step 3: Compile with RIOT OS

3.1 Create Code for Embedding Model in C

File: 0301sin.c
Info: .

• Write 0301sin.c

#include <tvmgen_default.h>
#include "model_io_vars.h"

int ch=0;
scanf("%d", &ch);
input = (float)(ch*1.0/100);
tvmgen_default_run(&default_inputs, &default_outputs);
printf("Input: %d, output: %d\n", (int)(input*100), (int)(output*100));

• Write model_io_vars.h

#include <stdio.h>

#include <tvmgen_default.h>

static float input;
static float output;
struct tvmgen_default_inputs default_inputs = {.input0 = &input,};
struct tvmgen_default_outputs default_outputs = {.output = &output,};

int main(void)
{
    while(1){
        int ch=0;
        scanf("%d", &ch);
        printf("Input Number is: %d\n", ch);
        
        input = (float)((float)ch*1.0/180.0*3.14159265);

        tvmgen_default_run(&default_inputs, &default_outputs);
        printf("Output Sine Value: %d\n", (int)(output*100));
        
    }
    return 0;
}

• Input and output Refer to Model Code generated by TVM.
  Source : ./models/default/default.tar/codegen/host/include/tvmgen_default.h

/*!
 * \brief Input tensor pointers for TVM module "default" 
 */
struct tvmgen_default_inputs {
  void* input0;
};

/*!
 * \brief Output tensor pointers for TVM module "default" 
 */
struct tvmgen_default_outputs {
  void* output;
};

/*!
 * \brief entrypoint function for TVM module "default"
 * \param inputs Input tensors for the module 
 * \param outputs Output tensors for the module 
 */
int32_t tvmgen_default_run(
  struct tvmgen_default_inputs* inputs,
  struct tvmgen_default_outputs* outputs
);

3.2 Download RIOT OS and Write Makefile

RIOT OS Web for information.
RIOT OS CODE for testing.

git clone https://github.com/RIOT-OS/RIOT.git 

• Create Makefile in ROOT Directory

RIOTBASE= ./RIOT

BOARD ?= stm32f746g-disco
APPLICATION = SINE

EXTERNAL_PKG_DIRS += models

USEPKG += default 
USEMODULE += stdin

include $(RIOTBASE)/Makefile.include

CFLAGS += -Wno-strict-prototypes 
CFLAGS += -Wno-missing-include-dirs

override BINARY := $(ELFFILE)

• Create Makefile in ./models/default Directory

include $(RIOTBASE)/makefiles/utvm.inc.mk

• Create utvm.inc.mk in ./RIOT/makefiles Directory

_CURDIR := $(shell basename $(CURDIR))
UTVM_NAME ?= $(_CURDIR)
UTVM_DIR_BASE ?= $(BINDIR)/utvm
UTVM_MODEL_DIR = $(UTVM_DIR_BASE)/$(UTVM_NAME)

all:
	$(QQ)"$(MAKE)" -C $(UTVM_MODEL_DIR)/codegen/host/src -f $(RIOTBASE)/makefiles/utvm/Makefile.utvm \
		UTVM_MODULE_NAME=$(UTVM_NAME) UTVM_NAME=$(UTVM_NAME) UTVM_MODEL_DIR=$(UTVM_MODEL_DIR)

prepare: $(CURDIR)/$(UTVM_NAME).tar
	mkdir -p $(UTVM_MODEL_DIR)
	tar --extract --file=$< --directory $(UTVM_MODEL_DIR) --touch

clean:
	$(QQ)rm -Rf $(UTVM_MODEL_DIR)

• Create Makefile.utvm in ./RIOT/makefiles/utvm Directory

MODULE := $(UTVM_MODULE_NAME)

CFLAGS += -I$(UTVM_MODEL_DIR)/runtime/include
CFLAGS += -I$(UTVM_MODEL_DIR)/codegen/host/include
CFLAGS += -Wno-pedantic 
CFLAGS += -Wno-attributes
CFLAGS += -Wno-incompatible-pointer-types
CFLAGS += -Wno-cast-align
CFLAGS += -Wno-unused-parameter
CFLAGS += -Wno-unused-variable

include  $(RIOTBASE)/Makefile.base

Step 4: Compile, Flash and Test

make flash

make term

Thanks to U-TOE project, and RIOT project.