micropython · VynDragon · Sep 15, 2026
diff --git a/ports/zephyr/Kconfig b/ports/zephyr/Kconfig
@@ -83,6 +83,37 @@ choice MICROPY_CONFIG_ROM_LEVEL
 
 endchoice
 
+choice MICROPY_GETCHAR
+	prompt  "Getchar driver to use for the console"
+	default MICROPY_GETCHAR_CONSOLE_DRIVER
+
+	config MICROPY_GETCHAR_CONSOLE_DRIVER
+		bool "Use the console driver getchar"
+		depends on UART_CONSOLE
+		depends on UART_CONSOLE_DEBUG_SERVER_HOOKS
+		help
+			Use the uart_console driver API directly to access interrupts via a mix
+			of UART-like drivers and standard I/O. The console buffer is managed by
+			MicroPython.
+
+	config MICROPY_GETCHAR_CONSOLE_SUBSYS
+		bool "Use the console subsys getchar"
+		depends on CONSOLE_SUBSYS
+		depends on CONSOLE_GETCHAR
+		help
+			Let Zephyr handle all the console management including the buffers via
+			the console subsystem.
+
+endchoice
+
+if MICROPY_GETCHAR_CONSOLE_DRIVER
+
+config MICROPY_GETCHAR_CONSOLE_DRIVER_BUF_SIZE
+	int "Size of the console driver getchar buffer"
+	default 1024
+
+endif # MICROPY_GETCHAR_CONSOLE_DRIVER
+
 endmenu # MicroPython Options
 
 source "Kconfig.zephyr"
diff --git a/ports/zephyr/boards/ai_m61_32s_kit.conf b/ports/zephyr/boards/ai_m61_32s_kit.conf
@@ -2,10 +2,6 @@
 CONFIG_PINCTRL=y
 CONFIG_GPIO=y
 CONFIG_WATCHDOG=y
-CONFIG_CONSOLE_SUBSYS=y
-CONFIG_CONSOLE_GETCHAR=y
-CONFIG_CONSOLE_GETCHAR_BUFSIZE=1024
-CONFIG_CONSOLE_PUTCHAR_BUFSIZE=1024
 CONFIG_I2C=y
 CONFIG_I2C_TARGET=y
 CONFIG_SPI=y

diff --git a/ports/zephyr/boards/ai_m62_12f_kit.conf b/ports/zephyr/boards/ai_m62_12f_kit.conf
@@ -2,10 +2,6 @@
 CONFIG_PINCTRL=y
 CONFIG_GPIO=y
 CONFIG_WATCHDOG=y
-CONFIG_CONSOLE_SUBSYS=y
-CONFIG_CONSOLE_GETCHAR=y
-CONFIG_CONSOLE_GETCHAR_BUFSIZE=1024
-CONFIG_CONSOLE_PUTCHAR_BUFSIZE=1024
 CONFIG_I2C=y
 CONFIG_I2C_TARGET=y
 CONFIG_SPI=y

diff --git a/ports/zephyr/boards/ai_m64p_32s_kit.conf b/ports/zephyr/boards/ai_m64p_32s_kit.conf
@@ -2,10 +2,6 @@
 CONFIG_PINCTRL=y
 CONFIG_GPIO=y
 CONFIG_WATCHDOG=y
-CONFIG_CONSOLE_SUBSYS=y
-CONFIG_CONSOLE_GETCHAR=y
-CONFIG_CONSOLE_GETCHAR_BUFSIZE=1024
-CONFIG_CONSOLE_PUTCHAR_BUFSIZE=1024
 CONFIG_I2C=y
 CONFIG_I2C_TARGET=y
 CONFIG_SPI=y

diff --git a/ports/zephyr/boards/ai_wb2_12f_kit.conf b/ports/zephyr/boards/ai_wb2_12f_kit.conf
@@ -2,10 +2,6 @@
 CONFIG_PINCTRL=y
 CONFIG_GPIO=y
 CONFIG_WATCHDOG=y
-CONFIG_CONSOLE_SUBSYS=y
-CONFIG_CONSOLE_GETCHAR=y
-CONFIG_CONSOLE_GETCHAR_BUFSIZE=1024
-CONFIG_CONSOLE_PUTCHAR_BUFSIZE=1024
 CONFIG_I2C=y
 CONFIG_I2C_TARGET=y
 CONFIG_SPI=y

diff --git a/ports/zephyr/main.c b/ports/zephyr/main.c
@@ -41,7 +41,7 @@
 
 #include <zephyr/storage/flash_map.h>
 
-#ifdef CONFIG_CONSOLE_SUBSYS
+#ifdef CONFIG_MICROPY_GETCHAR_CONSOLE_SUBSYS
 #include <zephyr/console/console.h>
 
 #if CONFIG_CONSOLE_GETCHAR_BUFSIZE < 512
@@ -129,13 +129,15 @@ void init_zephyr(void) {
 
 int main(void) {
     /* Initialize terminal device */
-    #ifdef CONFIG_CONSOLE_SUBSYS
+    #ifdef CONFIG_MICROPY_GETCHAR_CONSOLE_SUBSYS
     console_init();
     /* Always immediately hand control back to micropython */
     console_set_rx_timeout(K_NO_WAIT);
     console_set_tx_timeout(K_NO_WAIT);
-    #else
+    #elif CONFIG_MICROPY_GETCHAR_CONSOLE_DRIVER
     zephyr_getchar_init();
+    #else
+    #error A getchar driver must be chosen
     #endif
 
     #if MICROPY_PY_THREAD

diff --git a/ports/zephyr/src/zephyr_getchar.c b/ports/zephyr/src/zephyr_getchar.c
@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#ifdef CONFIG_MICROPY_GETCHAR_CONSOLE_DRIVER
+
 #include <zephyr/kernel.h>
 #include <zephyr/drivers/uart.h>
 #include <zephyr/drivers/console/uart_console.h>
@@ -24,12 +26,11 @@ extern int mp_interrupt_char;
 void mp_sched_keyboard_interrupt(void);
 void mp_hal_signal_event(void);
 
-#define UART_BUFSIZE (512)
-static uint8_t uart_ringbuf[UART_BUFSIZE];
-static uint16_t i_get, i_put;
+static uint8_t uart_ringbuf[CONFIG_MICROPY_GETCHAR_CONSOLE_DRIVER_BUF_SIZE];
+static uint16_t i_get = 0, i_put = 0;
 
 static int console_irq_input_hook(uint8_t ch) {
-    int i_next = (i_put + 1) & (UART_BUFSIZE - 1);
+    int i_next = (i_put + 1) & (CONFIG_MICROPY_GETCHAR_CONSOLE_DRIVER_BUF_SIZE - 1);
     if (i_next == i_get) {
         printk("UART buffer overflow - char dropped\n");
         return 1;
@@ -54,7 +55,7 @@ int zephyr_getchar(void) {
     if (i_get != i_put) {
         unsigned int key = irq_lock();
         int c = (int)uart_ringbuf[i_get++];
-        i_get &= UART_BUFSIZE - 1;
+        i_get &= CONFIG_MICROPY_GETCHAR_CONSOLE_DRIVER_BUF_SIZE - 1;
         irq_unlock(key);
         return c;
     }
@@ -66,3 +67,5 @@ void zephyr_getchar_init(void) {
     // All NULLs because we're interested only in the callback above
     uart_register_input(NULL, NULL, NULL);
 }
+
+#endif /* CONFIG_MICROPY_GETCHAR_CONSOLE_DRIVER */
diff --git a/ports/zephyr/src/zephyr_getchar.h b/ports/zephyr/src/zephyr_getchar.h
@@ -14,8 +14,15 @@
  * limitations under the License.
  */
 
-#include <stdint.h>
+#ifndef MICROPY_INCLUDED_ZEPHYR_SRC_ZEPHYR_GETCHAR_H
+#define MICROPY_INCLUDED_ZEPHYR_SRC_ZEPHYR_GETCHAR_H
+
+#ifdef CONFIG_MICROPY_GETCHAR_CONSOLE_DRIVER
 
 void zephyr_getchar_init(void);
 int zephyr_getchar_check(void);
 int zephyr_getchar(void);
+
+#endif
+
+#endif /* MICROPY_INCLUDED_ZEPHYR_SRC_ZEPHYR_GETCHAR_H */
diff --git a/ports/zephyr/uart_core.c b/ports/zephyr/uart_core.c
@@ -23,6 +23,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
+
 #include <unistd.h>
 #include "py/mpconfig.h"
 #include "py/runtime.h"
@@ -38,10 +39,14 @@
  * Core UART functions to implement for a port
  */
 
+#ifdef CONFIG_MICROPY_GETCHAR_CONSOLE_DRIVER
+static const struct device *const uart_console_dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_console));
+#endif
+
 uintptr_t mp_hal_stdio_poll(uintptr_t poll_flags) {
     uintptr_t ret = 0;
     if (poll_flags & MP_STREAM_POLL_RD) {
-        #ifdef CONFIG_CONSOLE_SUBSYS
+        #ifdef CONFIG_MICROPY_GETCHAR_CONSOLE_SUBSYS
         // It's not easy to test if tty is readable, so just unconditionally set it for now.
         ret |= MP_STREAM_POLL_RD;
         #else
@@ -60,7 +65,7 @@ uintptr_t mp_hal_stdio_poll(uintptr_t poll_flags) {
 int mp_hal_stdin_rx_chr(void) {
     for (;;) {
         int _chr;
-        #ifdef CONFIG_CONSOLE_SUBSYS
+        #ifdef CONFIG_MICROPY_GETCHAR_CONSOLE_SUBSYS
         _chr = console_getchar();
         #else
         _chr = zephyr_getchar();
@@ -75,7 +80,7 @@ int mp_hal_stdin_rx_chr(void) {
 // Send string of given length
 mp_uint_t mp_hal_stdout_tx_strn(const char *str, mp_uint_t len) {
     mp_uint_t ret = len;
-    #ifdef CONFIG_CONSOLE_SUBSYS
+    #ifdef CONFIG_MICROPY_GETCHAR_CONSOLE_SUBSYS
     while (len--) {
         char c = *str++;
         /* console_putchar returns -EAGAIN when no free tx is available */
@@ -84,9 +89,11 @@ mp_uint_t mp_hal_stdout_tx_strn(const char *str, mp_uint_t len) {
         }
     }
     #else
-    static const struct device *uart_console_dev =
-        DEVICE_DT_GET(DT_CHOSEN(zephyr_console));
-
+    /* Use poll out directly, because printk and other indirect uart_console access will append
+     * windows line returns to the output.
+     * This works for UART and UART-like serial drivers (CDC ACM) and is equivalent to the
+     * uart_console driver's output.
+     */
     while (len--) {
         uart_poll_out(uart_console_dev, *str++);
     }