ESP8266 Boot

ESP8266 启动

ESP8266 启动时，将从 UART0 以波特率 74880 打印：

 ets Jan  8 2013,rst cause:1, boot mode:(3,1)

load 0x40100000, len 26880, room 16 
tail 0
chksum 0x0a
load 0x3ffe8000, len 884, room 8 
tail 12
chksum 0x3f
ho 0 tail 12 room 4
load 0x3ffe8378, len 272, room 12 
tail 4
chksum 0xc7
csum 0xc7