esp32/sdkconfig: Change to use single core only.

dpgeorge · dpgeorge · commit 375a250db6cb · 2016-12-19T13:06:43.000+11:00
There seem to be random crashes when using both cores at the same time.
It's hard to reproduce, but, for example, changing the order of object
files on the command line to the linker can make the difference between
crash and no crash.  And the start up code will always get at least as far
as starting the PRO CPU.

Espressif also changed the default config setting to use only a single
core.

It may be related to SPI flash and cache because the SPI flash driver
plays some tricks to get both CPUs to stop while accessing the flash.
diff --git a/esp32/sdkconfig.h b/esp32/sdkconfig.h
@@ -23,7 +23,7 @@
 #define CONFIG_LWIP_MAX_SOCKETS 4
 #define CONFIG_ULP_COPROC_RESERVE_MEM 0
 #define CONFIG_ESPTOOLPY_BAUD 115200
-#define CONFIG_INT_WDT_CHECK_CPU1 1
+#define CONFIG_INT_WDT_CHECK_CPU1 0
 #define CONFIG_TOOLPREFIX "xtensa-esp32-elf-"
 #define CONFIG_CONSOLE_UART_NUM 0
 #define CONFIG_ESP32_RTC_CLOCK_SOURCE_INTERNAL_RC 1
@@ -66,6 +66,7 @@
 #define CONFIG_ESP32_DEBUG_OCDAWARE 1
 #define CONFIG_FREERTOS_BREAK_ON_SCHEDULER_START_JTAG 1
 #define CONFIG_MBEDTLS_HARDWARE_SHA 1
+#define CONFIG_FREERTOS_UNICORE 1
 #define CONFIG_FREERTOS_CORETIMER_0 1
 #define CONFIG_PARTITION_TABLE_CUSTOM_FILENAME "partitions.csv"
 #define CONFIG_FREERTOS_ISR_STACKSIZE 1536
