RT-Thread is an open-source embedded Real-Time Operating System (RTOS) that has been widely adopted in the Internet of Things (IoT) domain due to its rich components and excellent tailorability. TH4001 is a 32-bit Reduced Instruction Set Computer-V (RISC-V) processor chip targeted at lightweight embedded control scenarios. It suffers from limited on-chip Static Random Access Memory (SRAM) capacity and is not equipped with standard hardware peripherals such as the Universal Asynchronous Receiver/Transmitter (UART). To date, no mature solution exists for porting the RT-Thread operating system to the TH4001 platform. To fill this gap, this paper presents a complete RT-Thread porting scheme for the TH4001 chip, focusing on addressing the constraints of insufficient SRAM capacity and the lack of UART peripherals. The scheme adopts a hybrid loading and running architecture for system booting, and leverages the Programmable I/O (PIO) module to emulate a UART interface for console output. Experimental results demonstrate that the ported RT-Thread system boots successfully, runs the user main thread, and correctly performs context switching. This work serves as a reference solution for porting RTOS to similarly resource-constrained RISC-V chips.