The flashing is fine, but the whole SoC stucks in bootloop.
I tried several examples under esp8266-rtos-sample-code and under RTOS_SDK. The boot shows this:
ets Jan 8 2013,rst cause:2, boot mode:(3,6)
load 0x40100000, len 29960, room 16
tail 8
chksum 0xd4
load 0x3ffe8000, len 2136, room 0
tail 8
chksum 0x94
load 0x3ffe8860, len 6644, room 0
tail 4
chksum 0xa0
csum 0xa
OS SDK ver: 1.5.0-dev(950076a) compiled @ Nov 4 2016 19:29:32
þ
I tried with lower SPI frequency and several flash address (both 0x20000 and 0x40000).
I experienced that with flashing eagle.irom0text.bin to 0x20000 and eagle.flash.bin to 0x00000.
The 3.3V is provided by 7833.