Won't reboot after spurious crash. "W (32) rtc_clk: Bogus XTAL frequency: 0 MHz"

[novalight]

Hey, I've noticed recently some strange behavior: (I am using a custom board with 40MHz and 32kHz crystals, this is also set in sdkconfig)

1. The ESP32 crashes because of a "StoreProhibited", caused by _gettimeofday_r . I call gettimeofday in an if-branch that should never be entered in the given application.
2. It reboots and outputs:

Code: Select all

ets Jun  8 2016 00:22:57

rst:0xc (SW_CPU_RESET),boot:0x17 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:1
load:0x3fff0010,len:4
load:0x3fff0014,len:7772
load:0x40078000,len:0
load:0x40078000,len:13760
entry 0x40079384
W (32) rtc_clk: Bogus XTAL frequency: 0 MHz

3. The debug output contiues then on UART1:

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>>>...<<<
I (730) cpu_start: Pro cpu up.
I (733) cpu_start: Starting app cpu, entry point is 0x40080f8c
I (740) cpu_start: App cpu up.
I (744) heap_init: Initializing. RAM available for dynamic allocation:
I (751) heap_init: At 3FFAE6E0 len 00001920 (6 KiB): DRAM
I (757) heap_init: At 3FFBAB60 len 000254A0 (149 KiB): DRAM
I (763) heap_init: At 3FFE0440 len 00003BC0 (14 KiB): D/IRAM
I (770) heap_init: At 3FFE4350 len 0001BCB0 (111 KiB): D/IRAM
I (776) heap_init: At 40091000 len 0000F000 (60 KiB): IRAM
I (782) cpu_start: Pro cpu start user code

>>>>Log ends here, application is not executed<<<<

Probably an interesting side note: When de device boots in normal state it says:

Code: Select all

rst:0x1 (POWERON_RESET),boot:0x17 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:1
load:0x3fff0010,len:4
load:0x3fff0014,len:7772
load:0x40078000,len:0
load:0x40078000,len:13760
entry 0x40079384
W (32) rtc_clk: Possibly invalid CONFIG_ESP32_XTAL_FREQ setting (40MHz). Detected 40 MHz.

What could be the issue here? Probably some kind of thermal issue? The device is now outside where it gets quite cold at night.

[novalight]

FYI, since this bug looks quite serious to us (it prevents unattended operation of the device basically) I've created an issue on github:
https://github.com/espressif/esp-idf/issues/1132