how to format the MTD of SPI flash

Dear All,

i use a SPI flash memory connected to SPI0 CS2, i enabled MTD and related setting while configure the linux kernel.

while start up, i could get the info:

bfin-uart.0: ttyBF0 at MMIO 0xffc00400 (irq = 29) is a BFIN-UART               
bfin-uart.1: ttyBF1 at MMIO 0xffc02000 (irq = 31) is a BFIN-UART               
m25p80 spi0.2: found s25fl256s1, expected m25p16                               
m25p80 spi0.2: s25fl256s1 (32768 Kbytes)                                       
Creating 3 MTD partitions on "m25p80":                                         
0x000000000000-0x000000200000 : "bootloader(spi)"                              
0x000000200000-0x000000500000 : "linux kernel(spi)"                            
0x000000500000-0x000002000000 : "file system(spi)"                             
bfin_wdt: initialized: timeout=20 sec (nowayout=0)                             
                                                                               
                                                                               
BusyBox v1.20.2 (2013-06-30 15:27:52 HKT) hush - the humble shell              
                                                                               
root:/>

but i can't find any mtdblock on the folder /dev.

and i want to know how to format the mtd3 as FAT format or other format supported by blackfin.

I want to access them via mount command as filesystem.

by the way, on the docs web, it said a tool named bonnie++, but with buildroot 2012, i didn't see this selection. any suggestion?