From a2919a6fb2c433cafa5c528ee03ee9c86efb93d8 Mon Sep 17 00:00:00 2001 From: Jeff Epler Date: Wed, 15 Jul 2020 11:45:13 -0500 Subject: [PATCH] esp32s2: Use the device's EUI-48 address as unique ID On my hardware, esptool reports MAC: 7c:df:a1:02:6c:b8 after this change, the USB descriptor says SerialNumber: 7CDFA1026CB8 and microcontroller.cpu.id has >>> "".join("%02x" % byte for byte in microcontroller.cpu.uid) 'c7fd1a20c68b' Note that the nibble-swapping between USB and cpu.uid is typical. For instance, an stm32 board has USB SerialNumber 24002500F005D42445632302 but hex-converted microcontroller.cpu.id 420052000f504d4254363220. --- .../common-hal/microcontroller/Processor.c | 24 ++++++++++++++++++- .../common-hal/microcontroller/Processor.h | 2 +- ports/esp32s2/mpconfigport.mk | 2 +- 3 files changed, 25 insertions(+), 3 deletions(-) diff --git a/ports/esp32s2/common-hal/microcontroller/Processor.c b/ports/esp32s2/common-hal/microcontroller/Processor.c index 8eaf1a33d2..39b85a18b8 100644 --- a/ports/esp32s2/common-hal/microcontroller/Processor.c +++ b/ports/esp32s2/common-hal/microcontroller/Processor.c @@ -26,10 +26,14 @@ */ #include +#include + #include "common-hal/microcontroller/Processor.h" #include "py/runtime.h" #include "supervisor/shared/translate.h" +#include "soc/efuse_reg.h" + float common_hal_mcu_processor_get_temperature(void) { return NAN; } @@ -42,5 +46,23 @@ uint32_t common_hal_mcu_processor_get_frequency(void) { return 0; } -void common_hal_mcu_processor_get_uid(uint8_t raw_id[]) { +STATIC uint8_t swap_nibbles(uint8_t v) { + return ((v << 4) | (v >> 4)) & 0xff; +} + +void common_hal_mcu_processor_get_uid(uint8_t raw_id[]) { + 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 + uint32_t mac_address_part = REG_READ(EFUSE_RD_MAC_SPI_SYS_0_REG); + *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 + mac_address_part = REG_READ(EFUSE_RD_MAC_SPI_SYS_1_REG); + *ptr-- = swap_nibbles(mac_address_part & 0xff); mac_address_part >>= 8; + *ptr-- = swap_nibbles(mac_address_part & 0xff); } diff --git a/ports/esp32s2/common-hal/microcontroller/Processor.h b/ports/esp32s2/common-hal/microcontroller/Processor.h index a2ea261c8f..f6636b333c 100644 --- a/ports/esp32s2/common-hal/microcontroller/Processor.h +++ b/ports/esp32s2/common-hal/microcontroller/Processor.h @@ -27,7 +27,7 @@ #ifndef MICROPY_INCLUDED_LITEX_COMMON_HAL_MICROCONTROLLER_PROCESSOR_H #define MICROPY_INCLUDED_LITEX_COMMON_HAL_MICROCONTROLLER_PROCESSOR_H -#define COMMON_HAL_MCU_PROCESSOR_UID_LENGTH 15 +#define COMMON_HAL_MCU_PROCESSOR_UID_LENGTH 6 #include "py/obj.h" diff --git a/ports/esp32s2/mpconfigport.mk b/ports/esp32s2/mpconfigport.mk index 5686579b45..713ccbb094 100644 --- a/ports/esp32s2/mpconfigport.mk +++ b/ports/esp32s2/mpconfigport.mk @@ -7,7 +7,7 @@ MPY_TOOL_LONGINT_IMPL = -mlongint-impl=mpz INTERNAL_LIBM = 1 # Chip supplied serial number, in bytes -USB_SERIAL_NUMBER_LENGTH = 30 +USB_SERIAL_NUMBER_LENGTH = 12 # Longints can be implemented as mpz, as longlong, or not LONGINT_IMPL = MPZ