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espressif: use canonical factory MACs for processor UIDs #11494

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Merged
dhalbert merged 5 commits into from
Oct 5, 2026
+6 −54
Merged

espressif: use canonical factory MACs for processor UIDs #11494

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c37df81
Initialize ESP32-P4 unique ID from its factory MAC
ladyada-eagleclaw Oct 2, 2026
c2e2d09
Merge branch 'main' into fix-esp32p4-factory-uid
ladyada Oct 5, 2026
513a55f
espressif: avoid raising on P4 UID read failure
ladyada-eagleclaw Oct 5, 2026
758b81c
Merge branch 'main' into fix-esp32p4-factory-uid
ladyada Oct 5, 2026
4e53b02
espressif: use canonical factory MACs for processor UIDs
ladyada-eagleclaw Oct 5, 2026
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60 changes: 6 additions & 54 deletions ports/espressif/common-hal/microcontroller/Processor.c
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Original file line number Diff line number Diff line change
Expand Up @@ -15,12 +15,11 @@
#include "shared-bindings/microcontroller/Processor.h"
#include "shared-bindings/microcontroller/ResetReason.h"

#include "esp_mac.h"
#include "esp_sleep.h"
#include "esp_system.h"
#include "esp_pm.h"

#include "soc/efuse_reg.h"

#if !defined(CONFIG_IDF_TARGET_ESP32)
#include "driver/temperature_sensor.h"
#endif
Expand Down Expand Up @@ -111,59 +110,12 @@ void common_hal_mcu_processor_set_frequency(mcu_processor_obj_t *self, uint32_t
}
#endif

#ifndef CONFIG_IDF_TARGET_ESP32P4
static uint8_t swap_nibbles(uint8_t v) {
return ((v << 4) | (v >> 4)) & 0xff;
}
#endif

void common_hal_mcu_processor_get_uid(uint8_t raw_id[]) {
#ifndef CONFIG_IDF_TARGET_ESP32P4
memset(raw_id, 0, COMMON_HAL_MCU_PROCESSOR_UID_LENGTH);

uint8_t *ptr = &raw_id[COMMON_HAL_MCU_PROCESSOR_UID_LENGTH - 1];
// MAC address contains 48 bits (6 bytes), 32 in the low order word

#if defined(CONFIG_IDF_TARGET_ESP32)
uint32_t mac_address_part = REG_READ(EFUSE_BLK0_RDATA1_REG);
#elif defined(CONFIG_IDF_TARGET_ESP32H2)
uint32_t mac_address_part = REG_READ(EFUSE_RD_MAC_SYS_0_REG);
#elif defined(CONFIG_IDF_TARGET_ESP32C2)
uint32_t mac_address_part = REG_READ(EFUSE_RD_BLK2_DATA0_REG);
#elif defined(CONFIG_IDF_TARGET_ESP32C61) || defined(CONFIG_IDF_TARGET_ESP32C5)
uint32_t mac_address_part = REG_READ(EFUSE_RD_MAC_SYS0_REG);
#else
uint32_t mac_address_part = REG_READ(EFUSE_RD_MAC_SPI_SYS_0_REG);
#endif

*ptr-- = swap_nibbles(mac_address_part & 0xff);
mac_address_part >>= 8;
*ptr-- = swap_nibbles(mac_address_part & 0xff);
mac_address_part >>= 8;
*ptr-- = swap_nibbles(mac_address_part & 0xff);
mac_address_part >>= 8;
*ptr-- = swap_nibbles(mac_address_part & 0xff);

// and 16 in the high order word
#if defined(CONFIG_IDF_TARGET_ESP32)
mac_address_part = REG_READ(EFUSE_BLK0_RDATA2_REG);
#elif defined(CONFIG_IDF_TARGET_ESP32H2)
mac_address_part = REG_READ(EFUSE_RD_MAC_SYS_1_REG);
#elif defined(CONFIG_IDF_TARGET_ESP32C2)
mac_address_part = REG_READ(EFUSE_RD_BLK2_DATA1_REG);
#elif defined(CONFIG_IDF_TARGET_ESP32C61) || defined(CONFIG_IDF_TARGET_ESP32C5)
mac_address_part = REG_READ(EFUSE_RD_MAC_SYS1_REG);
#else
mac_address_part = REG_READ(EFUSE_RD_MAC_SPI_SYS_1_REG);
#endif

*ptr-- = swap_nibbles(mac_address_part & 0xff);
mac_address_part >>= 8;
*ptr-- = swap_nibbles(mac_address_part & 0xff);
#else
// TODO: Get UID for ESP32-P4.
return;
#endif
// The factory MAC is six bytes even on IEEE 802.15.4 chips.
// USB descriptor setup also calls this outside the VM, so do not raise.
if (esp_read_mac(raw_id, ESP_MAC_EFUSE_FACTORY) != ESP_OK) {
memset(raw_id, 0, COMMON_HAL_MCU_PROCESSOR_UID_LENGTH);
}
}

mcu_reset_reason_t common_hal_mcu_processor_get_reset_reason(void) {
Expand Down
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