helpers.cpp

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#include "esphome/core/helpers.h"
#include "esphome/core/defines.h"
 
#ifdef USE_RP2040
 
#include "esphome/core/hal.h"
 
#if defined(USE_WIFI)
#include <WiFi.h>
#include <pico/cyw43_arch.h>  // For cyw43_arch_lwip_begin/end (LwIPLock)
#elif defined(USE_ETHERNET)
#include <lwip_wrap.h>  // For LWIPMutex — LwIPLock mirrors its semantics (see below)
#include "esphome/components/ethernet/ethernet_component.h"
#endif
#include <hardware/structs/rosc.h>
#include <hardware/sync.h>
 
namespace esphome {
 
bool random_bytes(uint8_t *data, size_t len) {
  while (len-- != 0) {
    uint8_t result = 0;
    for (uint8_t i = 0; i < 8; i++) {
      result <<= 1;
      result |= rosc_hw->randombit;
    }
    *data++ = result;
  }
  return true;
}
 
// RP2040 Mutex is defined inline in helpers.h for RP2040/ESP8266 builds.
 
IRAM_ATTR InterruptLock::InterruptLock() { state_ = save_and_disable_interrupts(); }
IRAM_ATTR InterruptLock::~InterruptLock() { restore_interrupts(state_); }
 
// On RP2040, lwip callbacks run from a low-priority user IRQ context, not the
// main loop (see low_priority_irq_handler() in pico-sdk
// async_context_threadsafe_background.c). This applies to both WiFi (CYW43) and
// Ethernet (W5500) — both use async_context_threadsafe_background.
//
// Without locking, recv_fn() from IRQ context races with read_locked_() on the
// main loop, corrupting the shared rx_buf_ pbuf chain (use-after-free, pbuf_cat
// assertion failures). See esphome#10681.
//
// WiFi uses cyw43_arch_lwip_begin/end.
//
// For wired Ethernet, taking only the async_context lock is NOT enough. The
// W5500 GPIO IRQ path (LwipIntfDev::_irq) checks arduino-pico's `__inLWIP`
// counter to decide whether to defer packet processing. If we hold the
// async_context lock without bumping `__inLWIP`, an interrupt-driven packet
// arrival re-enters lwIP from IRQ context and corrupts pbufs (the `pbuf_cat`
// assertion crash on wiznet-w5500-evb-pico). We mirror arduino-pico's
// LWIPMutex (cores/rp2040/lwip_wrap.h) exactly: bump `__inLWIP`, take the
// lock, and on release re-unmask any GPIO IRQs that were deferred while we
// held it. We can't `using LwIPLock = LWIPMutex;` in helpers.h because
// pulling lwip_wrap.h there poisons many TUs with lwIP types.
//
// When neither WiFi nor Ethernet is configured, this is a no-op since
// there's no network stack and no lwip callbacks to race with.
#if defined(USE_WIFI)
LwIPLock::LwIPLock() { cyw43_arch_lwip_begin(); }
LwIPLock::~LwIPLock() { cyw43_arch_lwip_end(); }
#elif defined(USE_ETHERNET)
LwIPLock::LwIPLock() {
  __inLWIP++;
  ethernet_arch_lwip_begin();
}
LwIPLock::~LwIPLock() {
  ethernet_arch_lwip_end();
  __inLWIP--;
  if (__needsIRQEN && !__inLWIP) {
    __needsIRQEN = false;
    ethernet_arch_lwip_gpio_unmask();
  }
}
#else
LwIPLock::LwIPLock() {}
LwIPLock::~LwIPLock() {}
#endif
 
void get_mac_address_raw(uint8_t *mac) {  // NOLINT(readability-non-const-parameter)
#ifdef USE_WIFI
  WiFi.macAddress(mac);
#elif defined(USE_ETHERNET)
  ethernet::global_eth_component->get_eth_mac_address_raw(mac);
#endif
}
 
}  // namespace esphome
 
#endif  // USE_RP2040