RKLLM Qwen2 VL

Qwen2-VL is a multimodal vision-language model (VLM) developed by Alibaba. It provides strong visual perception, adapts to images of different resolutions and aspect ratios, and supports deeper understanding of long videos (20+ minutes). Qwen2-VL also supports multiple languages and can act as an “agent” for tasks such as phone control and robot instruction execution. This document explains how to deploy Qwen2-VL-2B-Instruct on RK3588 using the RKLLM toolchain and run hardware-accelerated inference on the built-in NPU.

Quick Start

Download the demo

Download the complete demo from ModelScope.

For virtual environment setup, refer to Virtual Environment Usage.

Device

python3 -m venv .venv && source .venv/bin/activate
pip install -U modelscope
modelscope download --model radxa/Qwen2-VL-2B-RKLLM --local_dir ./Qwen2-VL-2B-RKLLM

Run the Example

Device

cd Qwen2-VL-2B-RKLLM/demo_Linux_aarch64/
export LD_LIBRARY_PATH=./lib
chmod +x ./demo
./demo demo.jpg ../qwen2_vl_2b_vision_rk3588.rknn ../qwen2-vl-2b-instruct_W8A8_rk3588.rkllm 2048 4096 3 "<|vision_start|>" "<|vision_end|>" "<|image_pad|>"

Full Conversion Workflow

Prerequisites

Set up the development environment by following RKNN Installation and RKLLM Installation.

RKLLM currently only converts the language model part, so deploying a multimodal model requires converting the vision encoder with the RKNN toolchain.

Activate the virtual environment

For virtual environment setup, refer to Create Virtual Environment.

X64 Linux PC

conda activate rkllm
pip install -U huggingface_hub

Download the Model

X64 Linux PC

cd RK-SDK/rknn-llm/examples/multimodal_model_demo/
hf download Qwen/Qwen2-VL-2B-Instruct  --local-dir ./Qwen2-VL-2B-Instruct

Model Conversion

Generate static positional encodings.

X64 Linux PC

python export/export_vision_qwen2.py --step 1 --path ./Qwen2-VL-2B-Instruct

Parameter	Required	Description	Notes
step	Yes	Export step	1/2. When step==1, only generates cu_seqlens and rotary_pos_emb. When step==2, exports ONNX (run step==1 first).
path	No	Hugging Face model directory	Default: Qwen/Qwen2-VL-2B-Instruct
batch	No	Batch size	Default: 1
height	No	Image height	Default: 392
width	No	Image width	Default: 392
savepath	No	Output path for ONNX/RKNN	Default: qwen2-vl-2b/qwen2_vl_2b_vision.onnx

Export the vision module to ONNX.

X64 Linux PC

pip install onnx==1.18
python export/export_vision_qwen2.py --step 2 --path ./Qwen2-VL-2B-Instruct

Convert the vision module to RKNN. For RKNN virtual environment setup, refer to Create Virtual Environment.

X64 Linux PC

conda activate rknn
python export/export_vision_rknn.py --path /path/to/save/qwen2-vl-vision.onnx --target-platform rk3588

Generate a quantization calibration file.

X64 Linux PC

conda activate rkllm
python data/make_input_embeds_for_quantize.py --path /path/to/Qwen2-VL-model

Parameter	Required	Description	Notes
path	Yes	Hugging Face model directory	N/A

Export the language module to the RKLLM format.

X64 Linux PC

python export/export_rkllm.py

Parameter	Required	Description	Notes
path	No	Hugging Face model directory	Default: Qwen/Qwen2-VL-2B-Instruct
target-platform	No	Target platform	rk3588 / rk3576 / rk3562 (default: rk3588)
num_npu_core	No	NPU core count	rk3588: [1,2,3], rk3576: [1,2], rk3562: [1] (default: 3)
quantized_dtype	No	RKLLM quantization dtype	Defaults to w8a8 (supported options depend on the platform)
device	No	Device used during conversion	cpu / cuda (default: cpu)
savepath	No	Output RKLLM model path	Default: qwen2_vl_2b_instruct.rkllm

Build the executable

For cross-compiler setup, refer to Compiler Tools.

X64 Linux PC

cd deploy/
export GCC_COMPILER=/path/to/your/gcc/bin/aarch64-linux-gnu
bash build-linux.sh

The generated binaries are located at install/demo_Linux_aarch64.

Deploy to the device

Copy the converted models and the built demo_Linux_aarch64 directory to the device.

Device

cd demo_Linux_aarch64/
export RKLLM_LOG_LEVEL=1
export LD_LIBRARY_PATH=./lib
./demo demo.jpg ../qwen2_vl_2b_vision_rk3588.rknn ../qwen2-vl-2b-instruct_W8A8_rk3588.rkllm 2048 4096 3 "<|vision_start|>" "<|vision_end|>" "<|image_pad|>"

Run the demo. Type exit to quit.

Device

./demo demo.jpg ../qwen2_vl_2b_vision_rk3588.rknn ../qwen2-vl-2b-instruct_W8A8_rk3588.rkllm 2048 4096 3 "<|vision_start|>" "<|vision_end|>" "<|image_pad|>"

Parameter	Required	Description	Notes
image_path	Yes	Image path	N/A
encoder_model_path	Yes	Vision encoder RKNN	N/A
llm_model_path	Yes	Language model RKLLM	N/A
max_new_tokens	Yes	Max generated tokens	Must be ≤ max_context_len
max_context_len	Yes	Max context length	Must be > text_token_num + image_token_num + max_new_tokens
core_num	Yes	NPU core count	rk3588: [1,2,3], rk3576: [1,2], rk3562: [1]

$ ./demo demo.jpg ../qwen2_vl_2b_vision_rk3588.rknn ../qwen2-vl-2b-instruct_W8A8_rk3588.rkllm 2048 4096 3
 "<|vision_start|>" "<|vision_end|>" "<|image_pad|>"
I rkllm: rkllm-runtime version: 1.2.3, rknpu driver version: 0.9.8, platform: RK3588
I rkllm: loading rkllm model from ../qwen2-vl-2b-instruct_W8A8_rk3588.rkllm
I rkllm: rkllm-toolkit version: 1.2.3, max_context_limit: 4096, npu_core_num: 3, target_platform: RK3588, model_dtype: W8A8
I rkllm: Enabled cpus: [4, 5, 6, 7]
I rkllm: Enabled cpus num: 4
I rkllm: Using mrope
rkllm init success
main: LLM Model loaded in  3052.79 ms
===the core num is 3===
model input num: 1, output num: 1
input tensors:
  index=0, name=onnx::Expand_0, n_dims=4, dims=[1, 392, 392, 3], n_elems=460992, size=921984, fmt=NHWC, type=FP16, qnt_type=AFFINE, zp=0, scale=1.000000
output tensors:
  index=0, name=4542, n_dims=2, dims=[196, 1536, 0, 0], n_elems=301056, size=602112, fmt=UNDEFINED, type=FP16, qnt_type=AFFINE, zp=0, scale=1.000000
model input height=392, width=392, channel=3
main: ImgEnc Model loaded in  2362.74 ms
main: ImgEnc Model inference took  3762.45 ms

**********************You can choose a preset question or type your own********************

[0] <image>What is in the image?

*************************************************************************

user: 0
<image>What is in the image?
assistant: The image depicts an astronaut sitting on a chair holding a green bottle, looking at Earth from the Moon with a starry sky in the background.

Test image:

Performance:

Stage	Total Time (ms)	Tokens	Time per Token (ms)	Tokens per Second
Prefill	929.40	222	4.19	238.86
Generate	3897.42	60	64.96	15.39