esp-open-rtos/core/include/esp/wdev_regs.h

/* esp/wdev_regs.h
 *
 * ESP8266 register definitions for the "wdev" region (0x3FF2xxx)
 *
 * In the DPORT memory space, alongside DPORT regs. However mostly
 * concerned with the WiFi hardware interface.
 *
 * Not compatible with ESP SDK register access code.
 */

#ifndef _ESP_WDEV_REGS_H
#define _ESP_WDEV_REGS_H

#include "esp/types.h"
#include "common_macros.h"

#define WDEV_BASE 0x3FF20000
#define WDEV (*(struct WDEV_REGS *)(WDEV_BASE))

/* Note: This memory region is not currently well understood.  Pretty much all
 * of the definitions here are from reverse-engineering the Espressif SDK code,
 * many are just educated guesses, and almost certainly some are misleading or
 * wrong.  If you can improve on any of this, please contribute!
 */

struct WDEV_REGS {
    uint32_t volatile _unknown0[768];  // 0x0000 - 0x0bfc
    uint32_t volatile SYS_TIME;        // 0x0c00
    uint32_t volatile _unknown1[144];  // 0x0c04 - 0x0e40
    uint32_t volatile HWRNG;           // 0xe44 HW RNG, see http://esp8266-re.foogod.com/wiki/Random_Number_Generator
} __attribute__ (( packed ));

_Static_assert(sizeof(struct WDEV_REGS) == 0xe48, "WDEV_REGS is the wrong size");

/* Extra paranoid check about the HWRNG address, as if this becomes
   wrong there will be no obvious symptoms apart from a lack of
   entropy.
*/
_Static_assert(&WDEV.HWRNG == (void*)0x3FF20E44, "HWRNG register is at wrong address");

#endif /* _ESP_WDEV_REGS_H */