Summary
The espefuse.py summary command reads the eFuses from the chip and outputs them in text or json format. It is also possible to save it to a file. The command also supports eFuse filtering by name.
Optional arguments:
--format- Select the summary format:summary- text format (default option).json- json format. Usage--format json.value_only- only the value of the eFuse specified as an argument will be displayed. For more information, refer to the Filtering eFuses section.
--file- File to save the efuse summary. Usage--file efuses.json.List of eFuses to filter. For more information, refer to the Filtering eFuses section.
Text Format Summary
The text format of summary consists of 3 main columns:
This column consists of the eFuse name and additional information: the block name associated with this eFuse field and encoding errors (if any).
Description of eFuse field.
This column has human readable value, read/write protection status, raw value (hexadecimal or binary).
Read and Write Protection Status
The R/W output indicates a protection status of a specific eFuse field/block:
-/Windicates that read protection is set. Value of such eFuse field will always show all-zeroes, even though hardware may use the correct value. In espefuse v2.6 and newer, read-protected eFuse values are displayed as question marks (??). On earlier versions, they are displayed as zeroes.BLOCK1 (BLOCK1): = ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? -/W
R/-indicates that write protection is set. No further bits can be set.-/-means both read and write protection are set.
Some eFuses have no protection at all, and some eFuses have only one read or write protection. There is no mark in the summary to expose it.
Display Efuse Summary
The eFuse summary may vary from version to version of this tool and differ for different chips. Below is the summary for the ESP32-C2 chip.
For details on the meaning of each eFuse value, refer to the Technical Reference Manual.
> espefuse.py -p PORT summary
Connecting...................
Detecting chip type... ESP32-C2
=== Run "summary" command ===
EFUSE_NAME (Block) Description = [Meaningful Value] [Readable/Writeable] (Hex Value)
----------------------------------------------------------------------------------------
Config fuses:
WR_DIS (BLOCK0) Disable programming of individual eFuses = 0 R/W (0x00)
RD_DIS (BLOCK0) Disable reading from BlOCK3 = 0 R/W (0b00)
UART_PRINT_CONTROL (BLOCK0) Set the default UARTboot message output mode = Enable R/W (0b00)
DIS_DIRECT_BOOT (BLOCK0) This bit set means disable direct_boot mode = False R/W (0b0)
Flash fuses:
FORCE_SEND_RESUME (BLOCK0) Set this bit to force ROM code to send a resume co = False R/W (0b0)
mmand during SPI boot
FLASH_TPUW (BLOCK0) Configures flash waiting time after power-up; in u = 0 R/W (0x0)
nit of ms. If the value is less than 15; the waiti
ng time is the configurable value. Otherwise; the
waiting time is twice the configurable value
Identity fuses:
DISABLE_WAFER_VERSION_MAJOR (BLOCK0) Disables check of wafer version major = False R/W (0b0)
DISABLE_BLK_VERSION_MAJOR (BLOCK0) Disables check of blk version major = False R/W (0b0)
WAFER_VERSION_MINOR (BLOCK2) WAFER_VERSION_MINOR = 0 R/W (0x0)
WAFER_VERSION_MAJOR (BLOCK2) WAFER_VERSION_MAJOR = 1 R/W (0b01)
PKG_VERSION (BLOCK2) EFUSE_PKG_VERSION = 1 R/W (0b001)
BLK_VERSION_MINOR (BLOCK2) Minor version of BLOCK2 = No calib R/W (0b000)
BLK_VERSION_MAJOR (BLOCK2) Major version of BLOCK2 = 0 R/W (0b00)
Jtag fuses:
DIS_PAD_JTAG (BLOCK0) Set this bit to disable pad jtag = False R/W (0b0)
Mac fuses:
CUSTOM_MAC_USED (BLOCK0) True if MAC_CUSTOM is burned = False R/W (0b0)
CUSTOM_MAC (BLOCK1) Custom MAC address
= 00:00:00:00:00:00 (OK) R/W
MAC (BLOCK2) MAC address
= 10:97:bd:f0:e5:28 (OK) R/W
Security fuses:
DIS_DOWNLOAD_ICACHE (BLOCK0) The bit be set to disable icache in download mode = False R/W (0b0)
DIS_DOWNLOAD_MANUAL_ENCRYPT (BLOCK0) The bit be set to disable manual encryption = False R/W (0b0)
SPI_BOOT_CRYPT_CNT (BLOCK0) Enables flash encryption when 1 or 3 bits are set = Disable R/W (0b000)
and disables otherwise
XTS_KEY_LENGTH_256 (BLOCK0) Flash encryption key length = 128 bits key R/W (0b0)
DIS_DOWNLOAD_MODE (BLOCK0) Set this bit to disable download mode (boot_mode[3 = False R/W (0b0)
:0] = 0; 1; 2; 4; 5; 6; 7)
ENABLE_SECURITY_DOWNLOAD (BLOCK0) Set this bit to enable secure UART download mode = False R/W (0b0)
SECURE_BOOT_EN (BLOCK0) The bit be set to enable secure boot = False R/W (0b0)
SECURE_VERSION (BLOCK0) Secure version for anti-rollback = 0 R/W (0x0)
BLOCK_KEY0 (BLOCK3) BLOCK_KEY0 - 256-bits. 256-bit key of Flash Encryp
= 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 R/W
tion
BLOCK_KEY0_LOW_128 (BLOCK3) BLOCK_KEY0 - lower 128-bits. 128-bit key of Flash
= 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 R/W
Encryption
BLOCK_KEY0_HI_128 (BLOCK3) BLOCK_KEY0 - higher 128-bits. 128-bits key of Secu
= 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 R/W
re Boot
Wdt fuses:
WDT_DELAY_SEL (BLOCK0) RTC watchdog timeout threshold; in unit of slow cl = 40000 R/W (0b00)
ock cycle
Json Format Summary
The json representation of eFuses for the ESP32 chip is shown below.
> espefuse.py summary --format json
{
"ABS_DONE_0": {
"bit_len": 1,
"block": 0,
"category": "security",
"description": "Secure boot V1 is enabled for bootloader image",
"efuse_type": "bool",
"name": "ABS_DONE_0",
"pos": 4,
"readable": true,
"value": false,
"word": 6,
"writeable": true
},
"BLOCK1": {
"bit_len": 256,
"block": 1,
"category": "security",
"description": "Flash encryption key",
"efuse_type": "bytes:32",
"name": "BLOCK1",
"pos": 0,
"readable": true,
"value": "00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00",
"word": 0,
"writeable": true
},
...
"CODING_SCHEME": {
"bit_len": 2,
"block": 0,
"category": "efuse",
"description": "Efuse variable block length scheme",
"efuse_type": "uint:2",
"name": "CODING_SCHEME",
"pos": 0,
"readable": true,
"value": "NONE (BLK1-3 len=256 bits)",
"word": 6,
"writeable": true
},
....
}
Save Json Format Summary To File
> espefuse.py summary --format json --file efuses.json
Connecting..........
Detecting chip type... Unsupported detection protocol, switching and trying again...
Connecting....
Detecting chip type... ESP32
=== Run "summary" command ===
Saving efuse values to efuses.json
Filtering Efuses and Displaying Only the Value
The espefuse.py summary command supports filtering eFuses by name. The eFuses to filter needs to be specified as positional arguments. If no eFuses are specified, complete summary will be displayed. Example:
> espefuse.py summary ABS_DONE_0 BLOCK1
=== Run "summary" command ===
EFUSE_NAME (Block) Description = [Meaningful Value] [Readable/Writeable] (Hex Value)
----------------------------------------------------------------------------------------
Security fuses:
ABS_DONE_0 (BLOCK0) Secure boot V1 is enabled for bootloader image = False R/W (0b0)
BLOCK1 (BLOCK1) Flash encryption key
= 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 R/W
If --format value_only is specified, only the value of the eFuse specified as an argument will be displayed. Only one eFuse can be specified as an argument for this format. Example:
> espefuse.py summary --format value_only MAC
=== Run "summary" command ===
00:00:00:00:00:00 (CRC 0x00 OK)