Reading efuse values on esp32s3

[stephanelsmith]

Leaving this here in case someone else needs it. I needed to write efuses with espfuse and then read them back out in micropython. Quick c module function white reads out the first 20 bytes of block 3, the rest being reserved.

// efuse definitions here
// primarily we are working with EFUSE_RD_USR_DATA0_REG which is block 3
// ~/esp-idf-v5.2.2/components/soc/esp32s3/include/soc/efuse_reg.h
#include "soc/efuse_reg.h"

static mp_obj_t mp_read_efuse_usr_data() {
    // the first 160 bits (20 bytes) are user allowed.  The remainder of the block is reserved, eg. custom mac
    uint8_t blk_usr_data[20];
    memcpy(blk_usr_data, (void *)EFUSE_RD_USR_DATA0_REG, sizeof(blk_usr_data));
    mp_obj_t mp_bufout = mp_obj_new_bytearray(sizeof(blk_usr_data), blk_usr_data);
    return mp_bufout;
}
static MP_DEFINE_CONST_FUN_OBJ_0(mp_read_efuse_usr_data_obj, mp_read_efuse_usr_data);

[jonnor]

Thank you for sharing!