diff --git a/ports/esp32/machine_adc.c b/ports/esp32/machine_adc.c
index 5ac05d56b5..6731978e28 100644
--- a/ports/esp32/machine_adc.c
+++ b/ports/esp32/machine_adc.c
@@ -164,10 +164,14 @@ STATIC mp_obj_t madc_width(mp_obj_t cls_in, mp_obj_t width_in) {
         case ADC_WIDTH_12Bit:
             adc_bit_width = 12;
             break;
-        #elif CONFIG_IDF_TARGET_ESP32S2 || CONFIG_IDF_TARGET_ESP32S3
+        #elif CONFIG_IDF_TARGET_ESP32S2
         case ADC_WIDTH_BIT_13:
             adc_bit_width = 13;
             break;
+        #elif CONFIG_IDF_TARGET_ESP32S3
+        case ADC_WIDTH_BIT_12:
+            adc_bit_width = 12;
+            break;
             #endif
         default:
             break;
@@ -194,8 +198,10 @@ STATIC const mp_rom_map_elem_t madc_locals_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR_WIDTH_10BIT), MP_ROM_INT(ADC_WIDTH_10Bit) },
     { MP_ROM_QSTR(MP_QSTR_WIDTH_11BIT), MP_ROM_INT(ADC_WIDTH_11Bit) },
     { MP_ROM_QSTR(MP_QSTR_WIDTH_12BIT), MP_ROM_INT(ADC_WIDTH_12Bit) },
-    #elif CONFIG_IDF_TARGET_ESP32S2 || CONFIG_IDF_TARGET_ESP32S3
+    #elif CONFIG_IDF_TARGET_ESP32S2
     { MP_ROM_QSTR(MP_QSTR_WIDTH_13BIT), MP_ROM_INT(ADC_WIDTH_BIT_13) },
+    #elif CONFIG_IDF_TARGET_ESP32S3
+    { MP_ROM_QSTR(MP_QSTR_WIDTH_12BIT), MP_ROM_INT(ADC_WIDTH_BIT_12) },
     #endif
 };
 
diff --git a/ports/esp32/machine_hw_spi.c b/ports/esp32/machine_hw_spi.c
index ca530ba943..4c0989b9a6 100644
--- a/ports/esp32/machine_hw_spi.c
+++ b/ports/esp32/machine_hw_spi.c
@@ -55,6 +55,8 @@
 
 #if CONFIG_IDF_TARGET_ESP32C3
 #define HSPI_HOST SPI2_HOST
+#elif CONFIG_IDF_TARGET_ESP32S3
+#define HSPI_HOST SPI3_HOST
 #endif
 
 typedef struct _machine_hw_spi_default_pins_t {
diff --git a/ports/esp32/machine_i2s.c b/ports/esp32/machine_i2s.c
index c650a33bef..dc583e8e96 100644
--- a/ports/esp32/machine_i2s.c
+++ b/ports/esp32/machine_i2s.c
@@ -455,8 +455,13 @@ STATIC void machine_i2s_init_helper(machine_i2s_obj_t *self, size_t n_pos_args,
     // apply low-level workaround for bug in some ESP-IDF versions that swap
     // the left and right channels
     // https://github.com/espressif/esp-idf/issues/6625
+    #if CONFIG_IDF_TARGET_ESP32S3
+    REG_SET_BIT(I2S_TX_CONF_REG(self->port), I2S_TX_MSB_SHIFT);
+    REG_SET_BIT(I2S_TX_CONF_REG(self->port), I2S_RX_MSB_SHIFT);
+    #else
     REG_SET_BIT(I2S_CONF_REG(self->port), I2S_TX_MSB_RIGHT);
     REG_SET_BIT(I2S_CONF_REG(self->port), I2S_RX_MSB_RIGHT);
+    #endif
 
     i2s_pin_config_t pin_config;
     pin_config.bck_io_num = self->sck;
diff --git a/ports/esp32/machine_timer.c b/ports/esp32/machine_timer.c
index 803849e1be..020ba4447d 100644
--- a/ports/esp32/machine_timer.c
+++ b/ports/esp32/machine_timer.c
@@ -138,7 +138,11 @@ STATIC void machine_timer_isr(void *self_in) {
     device->hw_timer[self->index].update = 1;
     #else
     #if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(4, 4, 0)
+    #if CONFIG_IDF_TARGET_ESP32S3
+    device->hw_timer[self->index].update.tn_update = 1;
+    #else
     device->hw_timer[self->index].update.tx_update = 1;
+    #endif
     #else
     device->hw_timer[self->index].update.update = 1;
     #endif
diff --git a/ports/esp32/modmachine.c b/ports/esp32/modmachine.c
index 00271a37ed..cca2015729 100644
--- a/ports/esp32/modmachine.c
+++ b/ports/esp32/modmachine.c
@@ -91,6 +91,8 @@ STATIC mp_obj_t machine_freq(size_t n_args, const mp_obj_t *args) {
         esp_pm_config_esp32c3_t pm;
         #elif CONFIG_IDF_TARGET_ESP32S2
         esp_pm_config_esp32s2_t pm;
+        #elif CONFIG_IDF_TARGET_ESP32S3
+        esp_pm_config_esp32s3_t pm;
         #endif
         pm.max_freq_mhz = freq;
         pm.min_freq_mhz = freq;
diff --git a/ports/esp32/partitions-8MiB.csv b/ports/esp32/partitions-8MiB.csv
new file mode 100644
index 0000000000..582d3b50e5
--- /dev/null
+++ b/ports/esp32/partitions-8MiB.csv
@@ -0,0 +1,7 @@
+# Notes: the offset of the partition table itself is set in
+# $IDF_PATH/components/partition_table/Kconfig.projbuild.
+# Name,   Type, SubType, Offset,  Size, Flags
+nvs,      data, nvs,     0x9000,  0x6000,
+phy_init, data, phy,     0xf000,  0x1000,
+factory,  app,  factory, 0x10000, 0x1F0000,
+vfs,      data, fat,     0x200000, 0x600000,
diff --git a/ports/esp32/uart.c b/ports/esp32/uart.c
index 480b364a59..58fc0c6c61 100644
--- a/ports/esp32/uart.c
+++ b/ports/esp32/uart.c
@@ -45,13 +45,18 @@ void uart_init(void) {
 // all code executed in ISR must be in IRAM, and any const data must be in DRAM
 STATIC void IRAM_ATTR uart_irq_handler(void *arg) {
     volatile uart_dev_t *uart = &UART0;
+    #if CONFIG_IDF_TARGET_ESP32S3
+    uart->int_clr.rxfifo_full_int_clr = 1;
+    uart->int_clr.rxfifo_tout_int_clr = 1;
+    #else
     uart->int_clr.rxfifo_full = 1;
-    uart->int_clr.frm_err = 1;
     uart->int_clr.rxfifo_tout = 1;
+    uart->int_clr.frm_err = 1;
+    #endif
     while (uart->status.rxfifo_cnt) {
         #if CONFIG_IDF_TARGET_ESP32
         uint8_t c = uart->fifo.rw_byte;
-        #elif CONFIG_IDF_TARGET_ESP32C3 || CONFIG_IDF_TARGET_ESP32S2
+        #elif CONFIG_IDF_TARGET_ESP32C3 || CONFIG_IDF_TARGET_ESP32S2 || CONFIG_IDF_TARGET_ESP32S3
         uint8_t c = READ_PERI_REG(UART_FIFO_AHB_REG(0)); // UART0
         #endif
         if (c == mp_interrupt_char) {