hathach · rhgndf · Jun 14, 2026 · Jun 14, 2026 · Jun 23, 2026 · Jul 4, 2026
diff --git a/README.rst b/README.rst
@@ -312,6 +312,8 @@ Supported CPUs
 |              | CH32V305, CH32V307          | 🟡     |      | ✅        | ch32_usbfs/hs          | ISO data loss [2]_ |
 |              +-----------------------------+--------+------+-----------+------------------------+--------------------+
 |              | CH583/2, CH32V103           | 🟡     |      | ❌        | ch32_usbfs             | ISO data loss [2]_ |
+|              +-----------------------------+--------+------+-----------+------------------------+--------------------+
+|              | CH32X033, CH32X035          | ✅     |      | ❌        | ch32_usbfs             | EP4 quirk          |
 +--------------+-----------------------------+--------+------+-----------+------------------------+--------------------+
 
 Table Legend

diff --git a/docs/reference/boards.rst b/docs/reference/boards.rst
@@ -363,17 +363,18 @@ fomu     fomu    fomu      https://tomu.im/fomu.html
 WCH
 ---
 
-==================  =============================  ========  =====================================================================  ======
-Board               Name                           Family    URL                                                                    Note
-==================  =============================  ========  =====================================================================  ======
-ch32f205r-r0        CH32F205r-r0                   ch32f20x  https://github.com/openwch/ch32f20x
-ch32v103c_bluepill  CH32V103C8T6-Bluepill          ch32v10x  https://stm32-base.org/boards/STM32F103C8T6-Blue-Pill
-ch32v103r_r1_1v0    CH32V103R-R1-1v1               ch32v10x  https://github.com/openwch/ch32v103/tree/main/SCHPCB/CH32V103R-R1-1v1
-ch32v203c_r0_1v0    CH32V203C-R0-1v0               ch32v20x  https://github.com/openwch/ch32v20x/tree/main/SCHPCB/CH32V203C-R0
-ch32v203g_r0_1v0    CH32V203G-R0-1v0               ch32v20x  https://github.com/openwch/ch32v20x/tree/main/SCHPCB/CH32V203C-R0
-nanoch32v203        nanoCH32V203                   ch32v20x  https://github.com/wuxx/nanoCH32V203
-ch32v307v_r1_1v0    CH32V307V-R1-1v0               ch32v30x  https://github.com/openwch/ch32v307/tree/main/SCHPCB/CH32V307V-R1-1v0
-nanoch32v305        nanoCH32V305                   ch32v30x  https://github.com/wuxx/nanoCH32V305
-ch582m_evt          CH582M-EVT evaluation board    ch583     https://www.wch-ic.com/products/CH582.html
-yd-ch582m           yd-ch582m from vcc-gnd studio  ch583     http://vcc-gnd.com/
-==================  =============================  ========  =====================================================================  ======
+===========================  =============================  ========  =====================================================================  ======
+Board                        Name                           Family    URL                                                                    Note
+===========================  =============================  ========  =====================================================================  ======
+ch32f205r-r0                 CH32F205r-r0                   ch32f20x  https://github.com/openwch/ch32f20x
+ch32v103c_bluepill           CH32V103C8T6-Bluepill          ch32v10x  https://stm32-base.org/boards/STM32F103C8T6-Blue-Pill
+ch32v103r_r1_1v0             CH32V103R-R1-1v1               ch32v10x  https://github.com/openwch/ch32v103/tree/main/SCHPCB/CH32V103R-R1-1v1
+ch32v203c_r0_1v0             CH32V203C-R0-1v0               ch32v20x  https://github.com/openwch/ch32v20x/tree/main/SCHPCB/CH32V203C-R0
+ch32v203g_r0_1v0             CH32V203G-R0-1v0               ch32v20x  https://github.com/openwch/ch32v20x/tree/main/SCHPCB/CH32V203C-R0
+nanoch32v203                 nanoCH32V203                   ch32v20x  https://github.com/wuxx/nanoCH32V203
+ch32v307v_r1_1v0             CH32V307V-R1-1v0               ch32v30x  https://github.com/openwch/ch32v307/tree/main/SCHPCB/CH32V307V-R1-1v0
+nanoch32v305                 nanoCH32V305                   ch32v30x  https://github.com/wuxx/nanoCH32V305
+ch582m_evt                   CH582M-EVT evaluation board    ch583     https://www.wch-ic.com/products/CH582.html
+yd-ch582m                    yd-ch582m from vcc-gnd studio  ch583     http://vcc-gnd.com/
+weact_ch32x035_core_board    WeAct CH32X035 Core Board      ch32x035  https://github.com/WeActStudio/WeActStudio.CH32X035CoreBoard
+===========================  =============================  ========  =====================================================================  ======
diff --git a/docs/reference/dependencies.rst b/docs/reference/dependencies.rst
@@ -91,6 +91,7 @@ hw/mcu/wch/ch32v103                       https://github.com/openwch/ch32v103.gi
 hw/mcu/wch/ch32v20x                       https://github.com/openwch/ch32v20x.git                           c4c38f507e258a4e69b059ccc2dc27dde33cea1b  ch32v20x
 hw/mcu/wch/ch32v307                       https://github.com/openwch/ch32v307.git                           184f21b852cb95eed58e86e901837bc9fff68775  ch32v30x
 hw/mcu/wch/ch583                          https://github.com/openwch/ch583.git                              bd508ad7ceed48377619837051412a651952857f  ch583
+hw/mcu/wch/ch32x035                       https://github.com/openwch/ch32x035.git                           c6253942b29ff2a3f5e2829182a874afffa45881  ch32x035
 lib/CMSIS_5                               https://github.com/ARM-software/CMSIS_5.git                       2b7495b8535bdcb306dac29b9ded4cfb679d7e5c  kinetis_k kinetis_kl lpc54 rw61x mm32 msp432e4 nrf samd2x_l2x lpc11 lpc13 lpc15 lpc17 lpc18 lpc40 lpc43 stm32c0 stm32f0 stm32f1 stm32f2 stm32f3 stm32f4 stm32f7 stm32g0 stm32g4 stm32h5 stm32h7 stm32h7rs stm32l0 stm32l1 stm32l4 stm32l5 stm32u0 stm32u5 stm32wb stm32wba sam3x samd11 samd21 samd2x_l2x samd51 samd5x_e5x same5x same7x samg tm4c
 lib/CMSIS_6                               https://github.com/ARM-software/CMSIS_6.git                       6f0a58d01aa9bd2feba212097f9afe7acd991d52  imxrt kinetis_k32l ra stm32n6 lpc51 lpc55 mcx stm32c5
 lib/FreeRTOS-Kernel                       https://github.com/FreeRTOS/FreeRTOS-Kernel.git                   9b777ae5c5b8e9e456065a00294d1e5f5f9facf5  all

diff --git a/examples/device/audio_4_channel_mic_freertos/skip.txt b/examples/device/audio_4_channel_mic_freertos/skip.txt
@@ -3,6 +3,7 @@ mcu:CH32V103
 mcu:CH32V20X
 mcu:CH32V307
 mcu:CH583
+mcu:CH32X035
 mcu:CXD56
 mcu:F1C100S
 mcu:GD32VF103

diff --git a/examples/device/audio_test_freertos/skip.txt b/examples/device/audio_test_freertos/skip.txt
@@ -3,6 +3,7 @@ mcu:CH32V103
 mcu:CH32V20X
 mcu:CH32V307
 mcu:CH583
+mcu:CH32X035
 mcu:CXD56
 mcu:F1C100S
 mcu:GD32VF103

diff --git a/examples/device/cdc_msc_freertos/skip.txt b/examples/device/cdc_msc_freertos/skip.txt
@@ -3,6 +3,7 @@ mcu:CH32V103
 mcu:CH32V20X
 mcu:CH32V307
 mcu:CH583
+mcu:CH32X035
 mcu:CXD56
 mcu:F1C100S
 mcu:GD32VF103

diff --git a/examples/device/hid_composite_freertos/skip.txt b/examples/device/hid_composite_freertos/skip.txt
@@ -3,6 +3,7 @@ mcu:CH32V103
 mcu:CH32V20X
 mcu:CH32V307
 mcu:CH583
+mcu:CH32X035
 mcu:CXD56
 mcu:F1C100S
 mcu:GD32VF103

diff --git a/examples/device/midi_test_freertos/skip.txt b/examples/device/midi_test_freertos/skip.txt
@@ -3,6 +3,7 @@ mcu:CH32V103
 mcu:CH32V20X
 mcu:CH32V307
 mcu:CH583
+mcu:CH32X035
 mcu:CXD56
 mcu:F1C100S
 mcu:GD32VF103

diff --git a/examples/device/net_lwip_webserver/skip.txt b/examples/device/net_lwip_webserver/skip.txt
@@ -1,5 +1,6 @@
 mcu:CH32V103
 mcu:CH32V20X
+mcu:CH32X035
 mcu:LPC11UXX
 mcu:LPC13XX
 mcu:LPC15XX

diff --git a/hw/bsp/ch32x035/boards/weact_ch32x035_core_board/board.cmake b/hw/bsp/ch32x035/boards/weact_ch32x035_core_board/board.cmake
@@ -0,0 +1,8 @@
+set(LD_FLASH_SIZE 62K)
+set(LD_RAM_SIZE 20K)
+
+function(update_board TARGET)
+  target_compile_definitions(${TARGET} PUBLIC
+    SYSCLK_FREQ_48MHz_HSI=48000000
+    )
+endfunction()
diff --git a/hw/bsp/ch32x035/boards/weact_ch32x035_core_board/board.h b/hw/bsp/ch32x035/boards/weact_ch32x035_core_board/board.h
@@ -0,0 +1,23 @@
+/* metadata:
+   name: WeAct CH32X035 Core Board
+   url: https://github.com/WeActStudio/WeActStudio.CH32X035CoreBoard
+*/
+
+#ifndef BOARD_H_
+#define BOARD_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define LED_PORT       GPIOB
+#define LED_PIN        GPIO_Pin_12
+#define LED_STATE_ON   1
+#define LED_CLOCK_EN() RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE)
+#define LED_MODE       GPIO_Mode_Out_PP
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/hw/bsp/ch32x035/boards/weact_ch32x035_core_board/board.mk b/hw/bsp/ch32x035/boards/weact_ch32x035_core_board/board.mk
@@ -0,0 +1,5 @@
+CFLAGS += -DSYSCLK_FREQ_48MHz_HSI=48000000
+
+LDFLAGS += \
+  -Wl,--defsym=__FLASH_SIZE=62K \
+  -Wl,--defsym=__RAM_SIZE=20K \
diff --git a/hw/bsp/ch32x035/ch32x035_conf.h b/hw/bsp/ch32x035/ch32x035_conf.h
@@ -0,0 +1,23 @@
+/********************************** (C) COPYRIGHT *******************************
+ * File Name          : ch32x035_conf.h
+ * Author             : WCH
+ * Version            : V1.0.0
+ * Date               : 2023/04/06
+ * Description        : Library configuration file.
+ *********************************************************************************
+ * Copyright (c) 2021 Nanjing Qinheng Microelectronics Co., Ltd.
+ * Attention: This software (modified or not) and binary are used for
+ * microcontroller manufactured by Nanjing Qinheng Microelectronics.
+ *******************************************************************************/
+#ifndef __CH32X035_CONF_H
+#define __CH32X035_CONF_H
+
+#include "ch32x035_dbgmcu.h"
+#include "ch32x035_flash.h"
+#include "ch32x035_gpio.h"
+#include "ch32x035_misc.h"
+#include "ch32x035_rcc.h"
+#include "ch32x035_usb.h"
+#include "ch32x035_usart.h"
+
+#endif
diff --git a/hw/bsp/ch32x035/ch32x035_it.h b/hw/bsp/ch32x035/ch32x035_it.h
@@ -0,0 +1,29 @@
+/********************************** (C) COPYRIGHT *******************************
+ * File Name          : ch32x035_it.h
+ * Author             : WCH
+ * Version            : V1.0.0
+ * Date               : 2023/04/06
+ * Description        : This file contains the headers of the interrupt handlers.
+ *********************************************************************************
+ * Copyright (c) 2021 Nanjing Qinheng Microelectronics Co., Ltd.
+ * Attention: This software (modified or not) and binary are used for
+ * microcontroller manufactured by Nanjing Qinheng Microelectronics.
+ *******************************************************************************/
+#ifndef __CH32X035_IT_H
+#define __CH32X035_IT_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "ch32x035.h"
+
+void USBFS_IRQHandler(void);
+void USBFSWakeUp_IRQHandler(void);
+void SysTick_Handler(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/hw/bsp/ch32x035/family.c b/hw/bsp/ch32x035/family.c
@@ -0,0 +1,176 @@
+/* metadata:
+manufacturer: WCH
+*/
+
+#include <stdio.h>
+
+// https://github.com/openwch/ch32v307/pull/90
+// https://github.com/openwch/ch32v20x/pull/12
+#ifdef __GNUC__
+  #pragma GCC diagnostic push
+  #pragma GCC diagnostic ignored "-Wstrict-prototypes"
+#endif
+
+#include "ch32x035.h"
+#include "ch32x035_it.h"
+
+#ifdef __GNUC__
+  #pragma GCC diagnostic pop
+#endif
+
+#include "bsp/board_api.h"
+#include "board.h"
+
+__attribute__((interrupt)) __attribute__((used)) void USBFS_IRQHandler(void) {
+#if CFG_TUD_ENABLED && CFG_TUD_WCH_USBIP_USBFS
+  tud_int_handler(0);
+#endif
+}
+
+__attribute__((interrupt)) __attribute__((used)) void USBFSWakeUp_IRQHandler(void) {
+#if CFG_TUD_ENABLED && CFG_TUD_WCH_USBIP_USBFS
+  tud_int_handler(0);
+#endif
+}
+
+//--------------------------------------------------------------------+
+// Board API
+//--------------------------------------------------------------------+
+#if CFG_TUSB_OS == OPT_OS_NONE
+volatile uint32_t system_ticks = 0;
+
+__attribute__((interrupt)) void SysTick_Handler(void) {
+  SysTick->SR = 0;
+  system_ticks++;
+}
+
+static uint32_t SysTick_Config(uint32_t ticks) {
+  NVIC_EnableIRQ(SysTicK_IRQn);
+  SysTick->CTLR = 0;
+  SysTick->SR   = 0;
+  SysTick->CNT  = 0;
+  SysTick->CMP  = ticks - 1;
+  SysTick->CTLR = 0xF;
+  return 0;
+}
+
+uint32_t tusb_time_millis_api(void) {
+  return system_ticks;
+}
+#endif
+
+void board_init(void) {
+  __disable_irq();
+
+  SystemCoreClockUpdate();
+
+#if CFG_TUSB_OS == OPT_OS_NONE
+  SysTick_Config(SystemCoreClock / 1000);
+#endif
+
+  LED_CLOCK_EN();
+
+  GPIO_InitTypeDef GPIO_InitStructure = {
+    .GPIO_Pin   = LED_PIN,
+    .GPIO_Mode  = LED_MODE,
+    .GPIO_Speed = GPIO_Speed_50MHz,
+  };
+  GPIO_Init(LED_PORT, &GPIO_InitStructure);
+
+  RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);
+  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE);
+  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_USBFS, ENABLE);
+
+  GPIO_InitStructure.GPIO_Pin  = GPIO_Pin_16;
+  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
+  GPIO_Init(GPIOC, &GPIO_InitStructure);
+
+  GPIO_InitStructure.GPIO_Pin  = GPIO_Pin_17;
+  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
+  GPIO_Init(GPIOC, &GPIO_InitStructure);
+
+  AFIO->CTLR = (AFIO->CTLR & ~(AFIO_CTLR_UDP_PUE | AFIO_CTLR_UDM_PUE)) | AFIO_CTLR_USB_PHY_V33 | AFIO_CTLR_UDP_PUE |
+               AFIO_CTLR_USB_IOEN;
+
+#ifdef UART_DEV
+  UART_CLOCK_EN();
+  GPIO_InitTypeDef usart_init = {
+    .GPIO_Pin   = UART_TX_PIN | UART_RX_PIN,
+    .GPIO_Speed = GPIO_Speed_50MHz,
+    .GPIO_Mode  = GPIO_Mode_AF_PP,
+  };
+  GPIO_Init(GPIOA, &usart_init);
+
+  USART_InitTypeDef usart = {
+    .USART_BaudRate            = 115200,
+    .USART_WordLength          = USART_WordLength_8b,
+    .USART_StopBits            = USART_StopBits_1,
+    .USART_Parity              = USART_Parity_No,
+    .USART_Mode                = USART_Mode_Tx | USART_Mode_Rx,
+    .USART_HardwareFlowControl = USART_HardwareFlowControl_None,
+  };
+  USART_Init(UART_DEV, &usart);
+  USART_Cmd(UART_DEV, ENABLE);
+#endif
+
+  __enable_irq();
+}
+
+void board_reset_to_bootloader(void) {
+}
+
+void board_led_write(bool state) {
+  GPIO_WriteBit(LED_PORT, LED_PIN, state ? LED_STATE_ON : (1 - LED_STATE_ON));
+}
+
+uint32_t board_button_read(void) {
+  return false;
+}
+
+size_t board_get_unique_id(uint8_t id[], size_t max_len) {
+  (void)max_len;
+  volatile uint32_t *ch32_uuid = ((volatile uint32_t *)0x1FFFF7E8UL);
+  uint32_t          *serial_32 = (uint32_t *)(uintptr_t)id;
+  serial_32[0]                 = ch32_uuid[0];
+  serial_32[1]                 = ch32_uuid[1];
+  serial_32[2]                 = ch32_uuid[2];
+
+  return 12;
+}
+
+int board_uart_read(uint8_t *buf, int len) {
+#ifdef UART_DEV
+  int count;
+  for (count = 0; count < len; count++) {
+    if (USART_GetFlagStatus(UART_DEV, USART_FLAG_RXNE) == RESET) {
+      break;
+    }
+    buf[count] = USART_ReceiveData(UART_DEV);
+  }
+  return count;
+#else
+  (void)buf;
+  (void)len;
+  return 0;
+#endif
+}
+
+int board_uart_write(const void *buf, int len) {
+#ifdef UART_DEV
+  const uint8_t *p     = (const uint8_t *)buf;
+  int            count = 0;
+  while (count < len) {
+    if (USART_GetFlagStatus(UART_DEV, USART_FLAG_TXE) != RESET) {
+      USART_SendData(UART_DEV, p[count]);
+      count++;
+    } else {
+      break;
+    }
+  }
+  return count;
+#else
+  (void)buf;
+  (void)len;
+  return 0;
+#endif
+}