ptn 4 name='kernel' start=N/A len=N/A (use hard-coded info. (cmd: movi))
ptn 5 name='ramdisk' start=N/A len=0x6800(~27262976KB) (use hard-coded info. (cmd: movi))
ptn 6 name='system' start=0x1000A len=0x502CA(~336275456KB)
ptn 7 name='userdata' start=0x1000A len=0x203AAA(~-2132104704KB)
ptn 8 name='cache' start=0x1000A len=0x8331C(~550268928KB)
ptn 9 name='fat' start=0x1000A len=0x44E659(~328820224KB)

从 name 这一项就基本可以确定是用来存什么的

这些是4412的但是我不知道FAT分区是干什么用的？