Remove build/ and use idf.py build to rebuild, it worked.

I tried to modify esp32.ld as below
/* IRAM for PRO cpu. Not sure if happy with this, this is MMU area... */
iram0_0_seg (RX) : org = 0x40080000, len = 0x10000

and macro in soc.h
#define SOC_IRAM_HIGH 0x400A0000
#define SOC_DIRAM_IRAM_LOW 0x400A0000
but it doesn't work. I use idf.py size ...