Modules with PSRAM take long to boot

[mcer12]

Seems like PSRAM is tested during boot, which can be disabled in menuconfonfig ("Run memory test on SPI RAM initialization" option). This causes ~500ms delay in boot. It would be nice to be able to disable the PSRAM test in arduino environment as well.

It is mentioned here:
https://esp32.com/viewtopic.php?t=9448

[SuGlider]

@mcer12
It seems disabled in sdkconfig. I tested a ESP32-WROVER and it boots instantaneously.
Could you provide us with some evidence of it?

[SuGlider]

This seems something related IDF 3.3
SPIRAM_MEMTEST was set to Yes by default.
It only has an effect on Arduino Core 1.0.6

But in version 2.0.0, that uses IDF 4.4, this option doesn't exist anymore in sdkconfig.

What is the Arduino Core Version you are currently using?
Would you consider using 2.0.0?

[mcer12]

@SuGlider when you tried it, did you enable PSRAM in the board settings? It boots up instantaneously for me as well but only when the PSRAM is disabled. And yes, I am running the latest arduino core.

[SuGlider]

@mcer12
I just retested it with Core Debug Level as Verbose.
I got a message in UART that indicates that Arduino Core is actually testing PSRAM:
[ 841][D][esp32-hal-psram.c:84] psramInit(): PSRAM enabled

Looking into Arduino Core code I found
https://github.com/espressif/arduino-esp32/blob/mem-optimized/cores/esp32/esp32-hal-psram.c#L69-L73

This is the place where it tests PSRAM and takes 500ms after booting.

@me-no-dev, is PSRAM test mandatory for Arduino or it can be skipped?

[mcer12]

Any news on this? I know 500ms doesn't seem like a big deal but on battery powered devices, it can mean weeks of extra deep sleep time :)

[SuGlider]

@mcer12
Sorry for the delay. I already have a solution for it.
Using BYPASS_SPIRAM_TEST(bool); will allow you to bypass PSRAM test and make the WROVER boot fast.

Example:

BYPASS_SPIRAM_TEST(true);

void setup() {
  Serial.begin(115200);
  Serial.println("\n Testing SPIRAM test bypass!");
  Serial.println("Check how long does it take to boot in a WROVER module.");
}

void loop() {
  static uint8_t count = 0;
  Serial.print("-");
  delay(500);
  if (++count == 32) {
    count = 0;
    Serial.println();
  }
}

[SuGlider]

The PR #6135 will solve your need.

[mcer12]

Thank you! Hope it gets approved soon.